PHYSICS, BIO & PROTECTION

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Who first demonstrated the fluoroscope? when?

Thomas Edison in 1898

Special wiring patterns ("wye","star","delta") used to create voltage waveforms that are placed 120 degrees out of phase wiaht one another, these voltage wafeforms are called what?

Three-phase alternating current

Adenine always bonds with ________.

Thymine

What type of cancer continues to be the main adverse health effect of the Chernobyl nuclear power accident?

Thyroid cancer

What is coast time?

Time it takes the rotor to rest after use

What is used to regulate the duration of x-ray exposure?

Timer

What is the function of a filter in diagnostic radiology?

To decrease the x-radiation dose to the patient's skin and superficial tissue

What is the purpose of x-ray beam filtration?

To filter out low energy x-ray photons. Filtration also results in lower patient dose.

27. What is the purpose of using a compensating filter?

To get a uniform picture.

What is the purpose of the autotransformer?

To vary and control the amplitude of the voltage supplied to the high-voltage step-up transformer and the filament transformer

The electron ejected during a Compton scattering interaction is called

a Compton electron (or Compton recoil electron)

List some examples of High-LET radiation:

*Alpha particles *Low-energy neutrons

The occupational effective dose limit of 50 mSv or 5 rem does NOT include:

*Background radiation *Exposure from personal medical procedures

List 4 types of radiosensitive cells:

*Basal cells of the skin *Blood cells such as lymphocytes & erythrocytes *Intestinal crypt cells *Reproductive (germ) cells

List 3 types of radioinsensitive (radioresistant) cells:

*Brain cells *Muscle cells *Nerve cells

Protective structural shielding is placed in the:

*Ceilings *Floors *Walls

List 3 examples of involuntary motion:

*Chills *Muscle spasms *Tremors

List 2 types of chromosome anomalies that have been observed at metaphase:

*Chromosome aberrations *Chromatid aberrations

List 2 types of chromosome anomalies:

*Chromosome aberrations *Chromatid aberrations

The amount of radiation dose received by a patient is usually specified in these 3 ways:

*ESE - Entrance skin exposure *Gonadal dose *GSD - Genetically significant dose

List 4 types of gonadal shielding devices:

*Flat contact shields * Clear lead shields *Shaped contact shields *Shadow shields

Radiographers receive the highest occupational exposure during:

*Fluoroscopy *Mobile radiography *Special procedures

When imaging a child, it is important to:

*Gain cooperation *Communicate *Use gonadal shielding *Collimate

Name the 3 radiation energy transfer determinants:

*LET (Linear Energy Transfer) *OER (Oxygen Enhancement Ratio *RBE (Relative Biological Effectiveness)

List 3 Radiation Energy Transfer Determinants:

*LET - Linear Energy Transfer *RBE - Relative Biological Effectiveness *OER - Oxygen Enhancement Ratio

To DECREASE patient exposure during fluoroscopic procedures, the fluoroscopist can:

*Limit the size of the fluoroscopic field to include only the area of anatomy that is of interest *Employ the practice of intermittent, or pulsed, fluoroscopy to reduce the overall length of exposure

List 2 General Categories of Radiation:

*Low-LET *High-LET

Name the 2 types of RNA:

*Messenger RNA (mRNA) *Transfer RNA (tRNA)

Avoiding repeats reduces:

*Patient exposure *Technologist exposure

List 6 functions of lipids:

*Reservoirs for long-term storage of energy *Insulate & guard body against environment *Support & protect organs *Provide essential substances necessary for growth & development *Lubricate the joints *Assist in digestive process

Name 2 types of nonlinear curves:

*Sigmoid *Linear Quadratic

List the Basic Principles of Radiation Protection for Personnel Exposure Reduction:

*Time *Distance *Shielding

Why was the Alliance for Radiation Safety in Pediatric Imaging founded?

*To increase awareness of the need to reduce patient dose for pediatric patients

these 2 organizations supply information to the (ICRP) International Commission on Radiological Protection

*UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) *NAS/NRC-BEIR (National Academy of Sciences/National Research Council Committee on the Biological Effects of Ionizing Radiation)

Name the 2 types of motion:

*Voluntary *Involuntary

List 2 examples of Low-LET radiation:

*X-rays *Gamma rays

List 2 functions of salts (electrolytes):

*aid in production of energy in the cell *Aid in conduction of nerves impulses

Secondary protective barriers are barriers from:

*leakage radiation *scatter

Dose reduction in mammography can be achieved by:

*limiting the number of projections taken *doing axillary projections ONLY on request of the radiologist

Dose response curves vary in 2 basic ways:

*linear or nonlinear *threshold or non-threshold

What where some of the doses received by workers at the Chernobyl plant from the explosion?

*more than 200 people rec'd 1 Sv (100 rem) whole body EqD *2 dozen people rec'd doses greater than 4 Sv (400 rem) *approx. 1/4 million people within 200 miles rec'd 0.2 Sv (20 rem) *some individuals rec'd thyroid doses exceeding several Sieverts from drinking milk containing radioactive iodine)

List the 2 types of nucleons:

*protons (positively charged)

After receiving radiation safety counseling, the pregnant radiologist technologist must read and sign a form for these 2 reasons:

*to acknowlege that she has received counseling *to confirm that she understands the ways to implement appropriate measures to ensure safety of the embryo-fetus.

*neutrons (no charge/neutral)

...

this term means "indivisible"

...

X-rays of any given energy are more penetrating in material with __________ than in material of ____________.

...more penetrating in material with low atomic number than in material of high atomic number.

What would be considered a negligible individual annual dose?

.001 rem

What is the typical radiation dose received on an airplane flight?

.005 to .01 mSv/hr or .5 to 1 mrem/hr

Dose limit to the embryo-fetus per month

.05 rem

The maximum monthly exposure to the fetus is

.05 rem

The annual effective dose limit for education and training is _____.

.1 rem

Dose limit for hospital workers, not radiology employees but may regularly visit x-ray

.1 rem per yr.

Dose limit to the embryo-fetus for the entire gestational period.

.5 rem

General public, infrequent exposure annual dose limit

.5 rem

The maximum exposure to the fetus over the entire gestation period is ____.

.5 rem

electrical charge of a neutron

0

electrical charge of an atom

0

What is the minimum safe dose?

0 rem

When 100% of light is transmitted, the optical density equals

0.0

Optical density (OD) can range from ___ to ___

0.0, 4.0

Fog density on a processed radiograph should not exceed ___

0.1

What is the small focal spot size range?

0.1 to 1 mm

Base plus fog OD has a range of approximately ____ to ____

0.1, 0.3

According to the U.S. Public Health Service, the estimated GSD for the U.S. population is about _______.

0.20 mSv or 20 mrem

All target interactions occur within this distance of the surface of the target.

0.25 - 0.5 mm

What whole body dose delivered within a few days produces a measureable hematologic depression?

0.25 Gy

Bucky slot shielding device should be a minimum of ____mm Pb.

0.25 mm

Protective curtain for the spot film device should be a minimum of ___mm Pb.

0.25 mm

What is the common thickness of lead gloves?

0.25 mm

List 3 thicknesses of lead aprons:

0.25 mm, 0.5 mm, 1.0 mm

When 50% of the light is transmitted, the optical density equals

0.3

What is the large focal spot size range?

0.3 to 2 mm

The log relative exposure (LRE) scale is usually presented in increments of ___, with each increment equal to _____ the exposure

0.3, doubling

What is the common thickness of lead eyeglasses?

0.35 mm

A dose of this level lessens the amount of platelets in human blood:

0.5 Gy

What is the common thickness of neck & thyroid shields?

0.5 mm

The Texas requirement for lead apron thickness is:

0.5 mm Pb

This lead thickness for aprons is most common:

0.5 mm Pb

The diagnostic range of optical density is between ___ and ___ OD

0.5, 2.0

When 25% of the light is transmitted, the optical density equals

0.6

The OER of high-LET radiation is approx. equal to ___.

1

a dose of 1 gray of beta particles, gamma rays or x-rays will give you a dose equivalent to...

1 Sievert (Sv)

One electric charge equals

1 coulomb ( 6.3 x 10^18 electrons)

What is the lowest reading for an OSL?

1 mrem

1 R =

1 rad or 1 rem

Cumulative effective dose limit for occupational exposure

1 rem x age

reproductive death occurs from exposures within this range:

1 to 10 Gy

What is the usual size of the aluminum (Al) metal filter in an x-ray imaging system?

1 to 5 mm

What is the Background Equivalent Radiation Time for a Lumbar spine exam?

1 yr

What percent of projectile kinetic energy is used for the production of x-radiation?

1%

What percent voltage ripple do high-frequency generators have?

1%

What percentage of carbohydrates are contained in the cell?

1%

What percentage of nucleic acids are contained in the cell?

1%

The FDA has recommended that a notation be placed in the patient's record if a skin dose in the range of ____ is received.

1-2 Gy

List 2 sources of added filtration:

1-mm or more sheets of aluminum permanently installed in the port of the x-ray tube housing, between the housing and the collimator the collimator

With an appropriate Pb equivalent in the barrier of the control booth, exposure of the radiographer will not exceed a max allowance of:

1mSv per week

What expose time does the electronic timer allow?

1ms (0.001 second)

The most radiosensitive period during pregnancy for radiation induced congenital abnormalities is during the _______.

1st trimester

Diagnostic x-rays should scatter a MINIMUM of ___ times before reaching any area behind the control booth barrier.

2

When radiation dose is low (below 2Gy), low-LET types of radiation have an OER of about ___.

2

single-phase power has this many pulses per 1/60 sec.

2

Source to image receptor distance must be accurate within ___%.

2 %

How many filaments does a cathode assemble have?

2 -- smalll one and large one

What radiation dose may cause temporary sterility?

2 Gy

A primary protective barrier of ___ mm Pb is required for an image intensifier unit.

2 mm

What is the approximate width and length of a filament?

2 mm in diameter & 1 to 2 cm in length

What is the weekly Maximum Permissible Dose for an uncontrolled area?

2 mrem

The risk of radiation-induced leukemia in children after a substantial dose of ionizing radiation is about ____that of adults.

2 times

Approx dose for body in CT imaging

2 to 4 rad

Because the binary system is used, bit depth is express as ______

2 to the power of n

What is the Background Equivalent Radiation Time for a patient who receives a Lower GI series?

2 yrs

Effective dose from Consumer

2%

What percentage of lipids are contained in the cell?

2%

Both alignment and length and width dimensions of the radiographic and light beams must correspond to within:

2% of the SID

If a radiograph transmits 0.32% of incident light as determined with a densitometer, what is the optical density (OD)

2.49

What amount of aluminum equivalent for total permanent filtration meets the minimum requirement for mobile diagnostic and fluoroscopic equipment?

2.5 mm aluminum equivalent

Roentgen (R) is equivalent to this:

2.58 x 10^-4 c/kg

There are ______ base pairs in the human genome that are arranged into approx. ________ genes.

2.9 billion....30,000

Approximately _____ of all radiation-induced damage is believed to be ultimately caused by the hydroxyl free radical (OH*).

2/3 (two-thirds)

the number of elements that have been artificially produced in high-energy particle accelerators

20

a dose of 1 gray of alpha particles will give you a dose equivalent to...

20 Sievert (Sv)

What is the maximum permitted equivalent dose in an uncontrolled area?

20 microSv (2 mrem)

A dose of ___ rads or more to a small area of the body can cause skin erythema.

200

The Alliance for Radiation Safety in Pediatric Imaging was founded in ____

2007

How many different amino acids does protein synthesis involve?

22

most x-ray imaging systems are designed to operate on this voltage

220 V power

primary side- 200 turns; secondary side - 400 turns; primary voltage 110V; secondary voltage = ______

220V

Germ cells have ____ chromosomes, which pair up to form a full set of ____ chromosomes when a sperm fertilizes an egg cell.

23...46

Effective dose from Computed Tomography

24%

What is the usual voltage range for diagnostic x-ray systems?

25 to 150 kVp

The rate of transfer of energy from ionizing radiation used for diagnostic purposes to soft biologic tissue is estimated to be _____ keV/um.

3

When the radiation dose is high, low-LET types of radiation have an OER of about _____.

3

The FDA states that the mean dose to the glandular tissue of a 4.5 cm compressed breast using filmscreen should not exceed ______ per view.

3 mGy (300 mrad)

What is the LD 50/30 (lethal dose) for humans?

3 to 4 Gy

A diagnostic x-ray beam usually has an HVL in the range of:

3 to 5 mm Al or 3 to 6 cm of soft tissue

Approx dose for head in CT imaging

3 to 5 rad

filaments normally operate at these currents:

3 to 6 amperes (A)

the speed of light as represented by the SI system of units

3 x 10^8 m/s

the velocity of all electromagnetic radiation

3 x 10^8 m/s

the speed of light

3 x 10^8 or 186,400 miles per second

Effective Terrestrial dose

3%

What is the rating (range) for a high-voltage generator for a basic radiographic unit?

30 to 50 kW

rating for a high-voltage generator in basic radiographic units

30 to 50 kw

At what mA can either focal spot size be used?

300 mA or less

The human eye can only distinguish between about ____ shades of gray at one time

32

An anode rotates at what rpm?

3300 to 10,000 rpm

What is the speed of most rotating anodes?

3400 rpm

What is the melting point of Tungsten?

3410 celcius

What is the melting point of tungsten?

3410 degrees Celcius

The LD50/60 for humans is approx. ____rads.

350

Full-wave rectified, three-phase units provide an x-ray beam at _____ pulses per second.

360

a full wave rectified three phase generator would have how many x-ray beam pulses per second?

360

Three-phase - 6 pulse waveforms contain how many pulses per second?

360 pulses per second

Effective dose from Radon & Thoron

37%

full-wave rectified x-ray imaging systems contain at least this many diodes in the high-voltage circuit

4

Radiation-induced leukemia has a latent period of ____ years.

4 to 7

Voltage ripple of three-phase, twelve-pulse generator

4%

What percent voltage ripple does three phase, twelve pulse power have?

4%

the numeric value for Planck's constant

4.15 x 10^-15

Fetal doses greater than ____ rem have been shown to greatly increase the incidence of severe mental retardation.

40

To double the output intensity by increasing kVp, one would have to raise the kVp by as much as _____.

40%

humidity range for film storage

40-60%

At what mA should you use only the large focal spot?

400 mA

A 12-bit depth can display ____ shades of gray

4096

A normal human being has ___ different chromosomes (____ pairs) in each somatic (nonreproductive) cell.

46...23 pairs

A shield is recommended if the ovaries and uterus are less than ____cm from any edge of the field.

5 cm

What is the lowest reading for a TLD?

5 mR

Most general purpose radiographic tubes, when operated at approximately 70 kVp, produce x-ray intensities of approximately...

5 mR/mAs at a 100 cm SID

Annual effective dose limit for occupational exposure

5 rem

What radiation dose may cause permanent sterilization?

5 to 6 Gy

Effective Internal dose

5%

Effective dose from Conventional Radiography

5%

Effective dose from Space

5%

What percentage of average radiation exposure to a human is due to medical x-rays?

5%

What is the normal white blood cell count for an adult?

5,000 to 10,000/mm of blood

Annual mammograms for women over ____ is recommended.

50

In Europe, Latin America, and other parts of the world, electric current is supplied at this frequency:

50 Hz

Federal government standards, enforcing a recommendation of the NCRP, permit diagnostic imaging personnel to receive an annual occupational effective dose of _____.

50 mSv or 5 rem

Dose limit to areas of skin, hands & feet for occupational workers

50 rem

Digital image receptors can produce an acceptable diagnostic image as long as the exposure is within +/- ____ of the intended exposure

50%

The central nervous system syndrome occurs following a whole body dose of ____ rads or more.

5000

three-phase power has this many pulses per 1/60 sec.

6

What is the Background Equivalent Radiation Time for a Thoracic Spine exam?

6 months

Three -phase waveforms my have how many pulses per cycle?

6 pulses per cycle or 12 pulses per cycle

a half wave rectified single phase generator would have how many x-ray beam pulses per second?

60

In the United States, electric current is supplied at this frequency:

60 Hz

What is the current from a common wall plug?

60 Hz AC (alternating current)

The LD50/60 is the dose of radiation to the whole-body that will result in death within ____ to ____% of the irradiated population.

60 days, 50%

What is the coast time in new x-ray tube?

60 s

A 16-bit depth can display _____ shades of gray

65,536

K-Characteristic x-rays require an x-ray tube potential of at least ______

69 kVp

What is the minimum required kVp to produce characteristic radiation?

69%

Control booth barriers must extend __ ft up from the floor and be permanently secured to the floor.

7

the periods in the Periodic Table of the Elements is represented by this

7 horizontal rows

Effective dose from Interventional Fluoroscopy

7%

Three-phase - 12 pulse waveforms contain how many pulses per second?

720 pulses per second

What is the atomic number of tungsten?

74

the groups in the Periodic Table of the Elements is represented by this

8 vertical columns

The greatest risk for radiation-induced mental retardation occurs when the embryo-fetus is exposed _____ weeks after conception.

8-15 weeks

Water accounts for what percentage of protoplasm?

80% to 85%

Water constitutes what % of the body?

80% to 85%

the maximum energy for an exposure taken at 90 kVp would be ____

90 keV

the number of naturally occurring elements

92

What percent of the kinetic energy of projectile electrons is converted to heat?

99%

Effective Industrial dose

< .1%

Effective Occupational Dose

< .1%

energy range for coherent scatter

< 10 keV

Voltage ripple of high-frequency generator

<1%

_______ of the kinetic energy of electrons is converted into x-rays

<1%

symbol for atomic mass number

A

2How much kVp will you reduce when changing from a single phase to three phase equipment?

A 12% reduction

How much kVp will reduce when changing from a single phase to a high frequency equipment?

A 16% reduction

Understand continuous x-ray emission spectrum and discrete x-ray emission spectrum.

A continuous spectrum contains all possible values and a discrete spectrum contains only specific values.

What does a anode consist of?

A metal target made of a tungsten-rhenium allow embeded in a disk of molubdenum with a motor to rotate the traget.

transformers only operate on this type of current

AC

Transformers requires what type of current?

AC (alternating current)

What is the usual output of an electrical generator?

AC (alternating current)

What type of current do transformers operate on?

AC (alternating current)

an electronic device designed to terminate x-ray exposure after properly exposing an image receptor

AEC

this type of timer may not respond properly at low kVp

AEC

acronym for as low as reasonably achievable

ALARA

the rate of change of velocity with time

Acceleration

List the 3 inorganic compounds found in the body:

Acids Bases *Salts (electrolytes)

Name the 2 purines:

Adenine Guanine

List the 4 nitrogenous organic bases that compose the rungs of the ladder in a DNA macromolecule:

Adenine Guanine Cytosine Thymine

an alternative to a grid for reducing scatter and improving contrast.

Air gap technique

What does the acronym ALARA stand for?

As Low As Reasonably Achievable

What is the difference between filament current and tube current?

At low filament current, there is no tube current because the filament does not get hot enough for thermionic emission. Because of thermionic emission, a small change in filament current results in a large change in tube current.

What is the number of protons plus the number of neutrons and is represented by the letter A called?

Atomic mass

What contains protons (positive charges) and neutrons (no charge); contains most of the mass of an atom?

Atomic nucleus

What equals the number of protons in the nucleus, is represented byt the letter Z, and that determines the chemical element?

Atomic number of an atom

model of atom with a central nucleus and well defined electron orbital paths

Bohr's

In the diagnostic range, most x-rays are this type:

Bremsstrahlung

This type of x-rays have a range of energies and form a continuous emission spectrum

Bremsstrahlung

X-rays that are produced when a projectile electron is slowed by the electric field of a target atom nucleus

Bremsstrahlung

A projectile electron misses outer shell electrons in the target and moves in close to the nucleus is called what?

Bremsstrahlung (bremms) radiation

X-ray tubes used in these modalities generally have a much shorter life

CT interventional radiology

______ is a late effect of radiation exposure.

Cancer

an electrical circuit device that stores electric charge

Capacitor

6.The negative side of the x-ray tube is called ______ and has two main parts ________ and __________

Cathode, Filament, Focusing cup

This results when projectile electron interaction is sufficiently violent to ionize the target atom through total removal of an inner-shell electron.

Characteristic X-rays

These are emitted when an outer-shell electron fills an inner-shell void.

Characteristic x-rays

This type of x-rays have precisely fixed (discrete) energies and form a discrete emission spectrum.

Characteristic x-rays

What is emitted when an other-shell electron fills an inner-shell void?

Characteristic x-rays

Explain how characteristic radiation is produced?

Characteristic x-rays are emitted from heavy elements when their electrons make transitions between the lower atomic energy levels.

Who cut exposure time in half by exposing two glass plates with emulsion sides together, leading to the development of double-emulsion film?

Charles Leonard

What is energy resulting form a chemical reaction?

Chemical energy

type of chromosome anomalie that results when irradiation of individual chromatids occurs later in interphase, after DNA sythesis has taken place

Chromatid aberration

type of chromosome anomalie that results when irradiation occurs early in interphase, before DNA synthesis takes place

Chromosome aberration

Which of the 2 types of chromosome anomalies is the most detrimental?

Chromosome aberrations

List 3 types of transformers:

Closed-core transformer Autotransformer *Shell-type transformer

Which x-ray interaction with matter is not considered to be important in radiography

Coherent scattering

Which x-ray interaction with matter occurs with low-energy x-rays, causes an atom to become temporarily excited, and results in the x-ray losing no energy and changing direction less than 20 degrees

Coherent scattering

Of compton and photoelectric, even though both decrease as kV increases, which is more prevalent at higher kV?

Compton

Scatter radiation can add unwanted exposure to the radiographic image as a result of ___

Compton interactions

interactions with matter occurring in the diagnostic energy range

Compton scatter and photoelectric

Which specific scattering interaction causes an outer shell electron to be ejected from an atom

Compton scattering

What are the 3 ways to electrify an object?

Contact Friction *Induction

area occupied by workers trained in radiation safety procedures and wearing radiation monitoring devices

Controlled area

the transfer of thermal energy from one position to another by a moving fluid medium

Convection

three components of Natural environmental radiation

Cosmic rays - terrestrial radiation - internally deposited radionuclides

What are the 3 Natural sources of whole-body radiation exposure?

Cosmic rays Terrestrial radiation *Internally deposited radionuclides

type of tube Roentgen was experimenting with when he discovered x-rays

Crooke's tube

A step-down transformer is used in the filament protion of the x-ray circuit to increase what?

Current flow to the chathode

What are the 3 types of area monitoring instruments?

Cutie pie (Ionization chamber) Geiger-Muller Detector *Proportional counter

Name the 2 Pyrimidines:

Cytosine Thymine

What type of current does an x-ray tube require?

DC (direct current)

What is the prototype for mRNA?

DNA

What serves as a prototype for messenger RNA (mRNA)?

DNA

composed of two long sugar-phosphate chains, twisted in a double-helix configuration

DNA

known as the "master chemical" found mostly in the cell nucleus and contains all the information the cell needs to function; a radiation-sensitive target molecule

DNA

What are the 2 types of nucleic acids?

DNA (deoxyribonucleic acid) RNA (ribonucleic acid)

person noted as describing elements being composed of identical atoms

Dalton

HVL may be defined as the thickness of a designated absorber required to:

Decrease the intensity of the primary beam by 50% of its initial value

Lipids are also known as what ugly, 4 letter word?

Fats

Ovaries are most radiosensitive during:

Fetal growth Early childhood

steps down the voltage to approximately 12 V and provides the current to heat the filament

Filament Heating Isolation Step-down Transformer

3 areas in diagnostic imaging that provide the greatest occupational exposure to radiation for radiologic technologists

Fluoroscopy Portables *C-arm

What surrounds the filaments on three sides?

Focusing cup

What 3 things must the body provide to ensure efficient cell operation?

Food Oxygen *Water

Secondary quantities that are derived from a combination of one or more of the three base quantities

Derived Quantity

What is electron cloud?

Describe where electrons are when they go around the nucleus of an atom

an electrical device that contains two electrodes

Diode

Undirectional folw of electrons in an electrical conductor is called what?

Direct Current (DC)

Name 2 factors that do not affect radiation quality

Distance & mAs

created the Periodic Table of the Elements

Dmitri Mendeleev

his work occurred 50 yrs after Dalton's work

Dmitri Mendeleev

showed that if the elements were arranged in order of increasing atomic mass, a periodic repetition of similar chemical properties occurred

Dmitri Mendeleev

most damaging break that cuts DNA in half

Double-strand break

Planck's Quantum Equation

E = hf (where E is the photon energy, "h" is Planck's constant, and "f" is the photon frequency in hertz)

Einstein's mass-energy equivalence equation

E = mc^2

Einstein's Relativity Equation

E = mc^2 (E is the energy measured in joules, "m" is the mass measured in kilograms, and "c" is the velocity of light measured in meters per second)

develops and enforces regulations pertaining to the control of environmental radiation

EPA (Environmental Protection Agency)

TLDs are used to measure

ESE (Entrance Skin Exposure)

What does a mA meter do?

Measures tube current in milliamperes.

type of cell division in which 2 cell divisions occur and 4 daughter cells are formed

Meiosis

Who developed the Periodic Table of the Elements?

Mendeleev

List the 3 units common to the SI and MKS systems:

Meter Kilogram *Second

Intensity of radiation is measeured in what unit?

Milligray in air

Intensity of radiation is measured in what unit?

Milligray in air (also called xray quanity)

the process of somatic cell division wherein a parent cell divides to form two daughter cells identical to the parent cell

Mitosis

List the 2 types of cell division:

Mitosis Meiosis

List 3 types of carbohydrates:

Monosaccharide Disaccharides *Polysaccharides

What will happen to the KE of the projectile electron when it interacts with the tungsten atom of the target material?

Most of the KE will turn into heat

What is inducing current flow in a secondary coil by varying the current flow through a primary coil called?

Mutual induction

Name the 2 types of semiconductors:

N-type P-type

reviews ICRP recommendations and implements them into U.S. radiation protection policy

NCRP (National Council on Radiation Protection and Measurements)

What is energy resulting form the nucleus of an atom?

Nuclear energy

Neutrons and protons

Nucleons

"City Hall"; controls every organelle in the cytoplasm along with the process of cell reproduction; must function properly for a cell to accomplish its normal activities & be able to duplicate itself

Nucleus

What is the formula for average gradient

OD2 - OD1 / LRE2 - LRE1

Numerically describes the oxygen effect that states that when irradiated in an oxygenated state, biologic tissue is more sensitive to radiation than when exposed to radiation without oxygen

OER (Oxygen Enhancement Ratio)

Because radiographers produce radiographs of three-dimensional objects, some size distortion always occurs as a result of ____

OID (some part of the object is always farther away from the image receptor resulting is more size distortion)

monitors the workplace and regulates occupational exposure to radiation

OSHA (Occupational Safety and Health Administration)

Factor used to modify the shielding requirement for a particular barrier by taking into account the fraction of the x-ray unit's workload for which there is an occupancy beyond that barrier

Occupancy Factor

T represents

Occupancy factor

What rule states that the outer shell of an atom may not contain more then eight electrons?

Octet rule

What law states that voltage in the circuit is equal to the current X resistace?

Ohm's Law

describes the manner in which electric currents behave in an electric circuit

Ohm's Law

V=IR

Ohm's law

List 5 major controls on the operator's console:

On/off control kVp selection mA selection time selection *AEC

Protoplasm consists of these 2 types of compounds:

Organic Inorganic

Without oxygen, damage produced by the indirect action of radiation on a biologic molecule my be repaired, but when damage occurs through an oxygen-mediated process, the end result is permanent, or fixed.

Oxygen Fixation Hypothesis

What type of radiation is alpha particles (helium nucleus - two protons and two neutrons), and beta particles (electronlike particles emitted from the nucleus of a radioactive atom)?

Particulated radiation

Name 5 Clinical skills required by the ARRT:

Patient Care Radiation protection Equipment Operation Image Production *Radiographic Procedures

List 8 examples of voluntary motion:

Patient's age Breathing patterns Anxiety Physical or mental discomfort Excitability Fear of exam Unfavorable prognosis Mental instability

an arrangement of all known elements into rows and columns

Periodic Table of the Elements

List the 3 principal types of magnets:

Permanent magnets Electromagnets *Superconducting magnets

What is the smallest amount of any type of electromagnetic radiation, is also considered a bundle of energy called a quantum, travels at the speed of light, and travels in waves in a stright path?

Photon

the study of interactions of matter and energy in all their diverse forms

Physics

the constant of proportionality is know as this:

Planck's constant

a single-strand break in the ladderlike DNA molecular structure

Point mutation

the 2 radioactive elements discovered by Marie and Pierre Curie

Polonium and Radium

What type of charge is a proton?

Positive

What is the anode?

Positive electrode in the x-ray tube

7 Forms of Energy

Potential - Kinetic - Chemical - Electrical - Thermal - Nuclear - Electromagnetic

What is energy of position?

Potential energy

Both ____ and ____ determine the amount of magnification of the anatomic structures on an image

SID, OID

___ and ____ play an important role in minimizing the amount of size distortion

SID, OID

___________ must be done in a way to minimize occupational dose and evenly distribute occupational dose to keep individual radiation doses ALARA.

Scheduling of radiographers

barriers from leakage radiation and scatter

Secondary protective barriers

What are the two types of electromagnetic induction?

Self induction and mutual induction.

What is opposing voltage created in a conductor by passing alternating current through it called?

Self-induction

Material that may act as an insulator or conductor under different conditions called?

Semiconductor

a material that can conduct an electric current or not, depending on the voltage applied across that material

Semiconductor

SI unit of occupational dose

Sievert

the SI equivalent for rem

Sievert (Sv)

Representation of electron flow as alternating current is called what?

Sine wave

What is waves of electromatnetic radiation?

Sine waves

What is the simplest type of current, has voltage that flows as a sine wave, has voltage that begins at zero and peaks at full value a the the crest of the wave then returns to zero, reverses, and again peaks on the inverse portion of the cycle at the trough?

Single-phase, two-pulse alternating current

the mathematical or graphical description of a simple harmonic motion

Sinusoidal variation

What is added to the filaments in the cathode assembly to reduce vaporization and prolong tube life?

Small amount of thorium

List the 2 types of endoplasmic reticulum:

Smooth ER Rough ER

2 developments that transformed the use of x-rays into a valuable medical specialty

Snook transformer Coolidge tube

Stakes of wire coil through which electrical current flows, creating overlapping force field lines is called what?

Solenoid

Electron cloud near the filament is called?

Space Charge

Phenomenon of the space charge that makes it difficult for subsequent electrons to be emitted by the filament because of electrostatic repulsion is called?

Space charge effect

Quantities derived from the base quantities that are used only in specialty areas of science, such as the units used in radiologic science

Special Quantity

Transformer that decrease voltage from the primary to the secondary coil and increases current in the same proportion is called what?

Step-down transformer

Does a step-up transformer or a step-down transformer have more turns in the secondary coil than in the primary coil?

Step-up transformer

Transformer that increases voltage from the primary to the secondary coil and decreases current in the same proportion is called what?

Step-up transformer

What composes the rails of the DNA ladder?

Sugar-phosphate compounds

Name the 4 types of timing circuits:

Synchronous Electronic Timers mAs Timers *Automatic Exposure Control

Antibodies are produced when other lymphocytes in the body, known as _____________, detect the presence of molecules that do not belong to the body.

T lymphocytes

True or False: Cine procedures can result in the highest patient doses of all diagnostic procedures.

TRUE

True or False: It is important that all radiographers are conscientiously employing radiation protection practices.

TRUE

True or False: Radiographers should not be allowed to get a dose close to 5 rem annually.

TRUE

True or False: When the frame rate is higher when using cine film in fluoroscopy, the radiation dose to the patient is also higher.

TRUE

the concept that DNA is the irreplaceable master molecule that serves as the vital target necessary for the survival of the cell; if DNA dies, the cell dies

Target Theory

a mathematical relationship describing the reduction in radiation intensity with distance from a point source.

The Inverse Square Law

energy can be transformed into another form or into matter, but it cannot be created or destroyed

The Law of Conservation of Energy

the first description of an atom having a nucleus

The Rutherford atom

List 3 effects to the x-ray beam of added filtration:

a beam with higher energy greater penetrability *better quality

tube tanning

a brownish-golden film on tube glass resulting from filament vaporizing

This type of spectrum contains all possible values

a continuous spectrum

Oersted proved what?

a current produces a magnetic field

This type of spectrum contains only specific values.

a discrete spectrum

Because of thermionic emission, a small change in filament current results in this:

a large change in tube current

faraday proved what?

a magnetic field in motion could produce an electric current

A charged particle in motion creates

a magnetic field.

Who determines the specifications for protective structural shielding of radiographic imaging rooms?

a medical physicist

atoms grouped together with other atoms form this

a molecule

When does a negative charge occur?

a negative charge occurs when there are more electrons than protons

List the 3 components that form nucleotides:

a nitrogen-containing organic base a five-carbon sugar molecule (deoxyribose) *a phosphate molecule

Rutherford's experiments in 1911 showed that the atom was composed of

a nucleus with an electron cloud.

What is the sensing agent in pocket ionization chambers?

a positive and negative electrode (ion pairs)

When does a positive charge occur?

a positive charge occurs when there are fewer electrons than protons

this allows the voltage to be monitored before an exposure

a prereading kVp meter

single-phase power results in this

a pulsating x-ray beam

the electronic device that allows current flow in only one direction

a rectifier

What type of transformer is a high-voltage transformer?

a step-up transformer

a precision device designed to drive a shaft at precisely 60 revolutions per second

a synchronous motor

What is the usual form of added filtration?

a thin sheet of aluminum positioned between the protective x-ray tube housing and the x-ray beam collimator

visible light behaves like

a wave

A decrease in quantity. An increase in quality.

an increase in added filtration

An increase in quantity and quality.

an increase in kVp (voltage)

An increase in quantity. No change in quality.

an increase in mAs (current)

An increase in quantity and quality.

an increase in target atomic number

A decrease in quantity and quality.

an increase in voltage ripple

a quantum of electromagnetic energy that travels through space at the speed of light

an x-ray photon

contains considerably more energy than a visible light photon or an RF photon

an x-ray photon

Bit depth is determined by the ____

analog-to-digital converter

What is angled if an image has foreshortening

anatomic part

where radiation is made in the x-ray tube

anode

means "without oxygen"

anoxic

foreign objects such as bacteria and flu viruses

antigens

this means programmed cell death

apoptosis

What is the inherent filtration of tubes made of beryllium?

approx. 0.1 mm Al equivalent

What is the inherent filtration of a general purpose x-ray tube?

approx. 0.5 mm Al equivalent

What is the distance between the filament and the x-ray tube?

approx. 1 cm

How much does the voltage fall during capacitor discharge?

approximately 1kV/mAs

the autotransformer can be designed to step up voltage to this amount:

approximately twice the input voltage value

tungsten vaporization can cause this tube failure issue

arcing

An ___ is any unwanted image on a radiograph; something that should not have been there or is not actually part of the patients anatomy

artifact

Errors such as double exposing an image receptor or the improper use of equipment can result in image _____ and must be avoided

artifacts

For photoelectric absorption to occur, the incoming x-ray photon must be ___ to the binding energy of the inner shell electron

at least equal

Where do x-rays interact?

at the electron level, or nuclear level, ionizing an atom or ejecting a nuclear particle

Where does a pregnant radiographer wear her fetal dose monitor?

at waist level, underneath the lead apron

[a (not) + temon (cut)] and is used to describe the smallest part of the four substances of matter

atom

smallest part of an element

atom

smallest particle of an element

atom

the smallest particle of matter that has all the properties of an element

atom

sources of manmade ionizing radiation?

atomic fallout, smoke detectors, nuclear power plants, medical x-rays

sum of proton's and neutrons in an atom determine the atom's ______.

atomic mass

the way in which the mass of an atomic particle is expressed when precision is not necessary (system of whole numbers)

atomic mass units (amu)

Increasing target _____ _______ enhances the efficiency of x-ray production and the energy of characteristic and bremsstrahlung x-rays.

atomic number

protons in an atom determine the atom's _____.

atomic number

to change the discrete x-ray emission spectrum, one would need to change this

atomic number of target material

all matter is composed of this

atoms

the fundamental, complex building blocks of matter

atoms and molecules

Where is the radiographic x-ray tube located?

attached to an overhead movable crane assembly

What is the reduction in the energy or number of photons in the primary x-ray beam as it interacts with anatomic tissue

attenuation

the reduction in x-ray intensity that results from absorption and scattering

attenuation

the reduction of x-ray beam intensity because of absorption and scatter

attenuation

Creating a radiographic image by differential absorption requires that these processes occur ______, ______, and ______

attenuation, absorption, transmission

unlike charges

attract

what type of transformer has a single winding

autotransformer

The first component to receive power in the x-ray circuit is the:

autotransformer.

The slope of a straight line drawn between 2 points on the characteristic curve at ODs 0.25 and 2.0 above base and fog is called

average gradient

What is the most often used method to numerically specify image receptor contrast

average gradient

model of atom with hooks and eyes to account for chemical combination

dalton's

If you have greater voltage ripple, you will have a ____ in image quality

decrease

If you have greater voltage ripple, you will have a ____ in image quantity

decrease

effect of an increase in kVp on compton scatter

decrease

emission specturm: increase filtration

decrease amplitude and shift to right

major benefit of using high kVp

decrease patient dose

As x-ray wavelength increases, x-ray energy _____.

decreases

as the distance between the source and image increases, x-ray quantity at the image _____

decreases

as the wavelength of a photon increases, the energy of the photon ______

decreases

Increasing the pixel density and ______ the pixel pitch increases spatial resolution

decreasing

Scatter has the effect of _____ by masking the desired brightness or densities on the image and change the degree of differences

decreasing the contrast

Scatter ____ or ____ the visibility of anatomic structures

degrades, decreases

A device used to numerically determine the amount of blackness on a radiograph

densitometer

____ is the amount of overall blackness on the processed film image

density

Visibility of the recorded detail is achieved by the proper balance of _____ and _____

density (image brightness), contrast

secondary quantities that are derived from a combination of one or more of the 3 base quantities

derived quantities

this imaging modality is not a part of the electromagnetic spectrum

diagnostic ultrasound

What would be the most likely immediate response to a whole body dose of 200 rads?

diarrhea, nausea, and vomiting

The process of image formation is a result of _____ of the x-ray beam as it interacts with anatomic tissue

differential absorption

What is a process whereby some of the x-ray beam is absorbed in the tissue and some passes through the anatomic part

differential absorption

the difference in x-ray interaction by various body tissue

differential absorption

In digital imaging, the latent image is stored as ____ and must be processed by the computer for viewing on a display monitor

digital data

an electronic device that contains two electrodes

diode

rectification is accomplished with these

diodes

two poles

dipole

What is the relationship between the production of heat in the anode, x-ray tube current & kVp in the diagnostic range?

direct

Anode angle and effective focal spot size are directly or indirectly proportional?

directly

For any given radiologic examination, how is the number of x-rays that reach the image receptor related to both the x-ray tube current and the time that the tube is energized?

directly

What is the relationship between x-ray quantity and mAs?

directly proportional

Characteristic radiations have ______ emission spectrum.

discrete

___ results from the radiographic misrepresentation of either the size or shape of the anatomic part

distortion

increases in atomic number of the absorber ______ compton interactions

do not affect

Scientists use epidemiologic studies to formulate ________ estimates to predict the risk of ______ in human populations exposed to low doses of ionizing radiation.

dose-response, cancer

In the diagnostic range, a 15% increase in kVp is equivalent to _________ the mAs to obtain a given OD on the radiograph.

doubling

When did radiologists begin using film?

during World War I

During this portion of the AC waveform, the rectifier does not conduct and no electric current is allowed.

during the negative portion of the AC waveform

When does the rectifier allow electric current to pass through the x-ray tube?

during the positive portion of the AC waveform

artifact that appears as white dots or specks on a film

dust

artifact that may appear as a white line on a digital image

dust on the laser

_____ refers to the range of exposure intensities an image receptor can accurately detect

dynamic range

Ancient Greek scientists thought that all matter was composed of these 4 substances:

earth water air fire

the reason radiology is now considered a safe occupation

effective radiation protection practices

the primary difference between a proton and a neutron

electric charge

the movement of electrons between atoms

electric current

Mechanical motion produces electric current in the :

electric generator

which system of the processor powers the motors that turn the gears attached to the rollers?

electrical

Name 3 functions of the anode in an x-ray tube:

electrical conductor provides mechanical support for the target *is a good thermal dissipator

A transformer converts:

electrical potential to higher or lower intensity.

a naturally occurring force that exists all around us

electricity

form of energy created by the activity of electrons and other subatomic particles in motion

electricity

natural forces that are closely related to one another

electricity & magnetism

an object is said to be this if it has too few or too many electrons

electrified

study of moving electric charges

electrodynamics

the study of electric charges in motion

electrodynamics

a field or state of energy that is always present around us and exists over a wide range called an energy continuum

electromagnetic energy

the reduction in intensity that results from scattering and absorption

electromagnetic energy attenuation

The rotating anode is powered by __________________ ____________motor.

electromagnetic induction

a means of transferring electric potential energy form one position to another, as in a transformer

electromagnetic induction

an electric current is induced in a circuit if some part of that circuit is in a changing magnetic field defines ________

electromagnetic induction

oscillating electric and magnetic fields that travel in a vacuum with the velocity of light. Includes x-rays, gamma rays, and some nonionizing radiation (such as ultraviolet, visible, infrared, and radio waves).

electromagnetic radiation or radiation

this includes the entire range of electromagnetic energy

electromagnetic spectrum

describes how electrons are given electric potential energy (voltage) and how electrons in motion create magnetism

electromagnetism

the smallest unit of negative charge

electron

this determines how the atom reacts chemically

electron arrangement in shells

the energy required to maintain electrons in orbit about the nucleus

electron binding energy

this term is used when medical imaging systems are described

electron flow

What is increased by raising the kVp and why?

electron kinetic energy is increased because all electrons have the same mass

rotation of electrons on their axis

electron spin

a unit measurement of energy in radiology

electron volt (eV)

most exposure timers are this type and are controlled by a microprocessor

electronic timers

the most sophisticated, most complicated, and most accurate of the x-ray exposure timers

electronic timers

electrification is due to the movement of these

electrons

the smallest & lightest of the particles in an atom

electrons

the smallest units of electric charge

electrons and protons

What are cathode rays?

electrons emitted from the filament of an electronic vacuum tube (ex: an x-ray tube)

What is another term for mAs?

electrostatic charge

mAs is the same as

electrostatic charge

what part of the image intensifier accelerates electrons?

electrostatic focusing lenses

the force of attraction between unlike charges or repulsion between like charges, due to the electric field

electrostatic force

Why doesn't an electron spontaneously fly away from the nucleus of an atom?

electrostatic force of attraction, electron binding energy

study of stationary electric charges

electrostatics

the study of stationary electric charges

electrostatics

___ refers to images of objects that appear longer than the true objects

elongation

What are the two types of shape distortion

elongation, foreshortening

the atom is comprised mostly of this (similar to our solar system)

empty space

In order to create and display a radiographic image on film, an active layer or ____ is adhered to a sheet of ______

emulsion, polyester plastic

the ability to do work

energy

the ability to do work or physically influence surroundings because of position

energy

x-rays are identified by their

energy

x-rays are identified by:

energy

List 2 advantages of the addition of 1% to 2% thorium to the tungsten filament:

enhances efficiency of thermionic emission prolongs tube life

these proteins function as organic catalysts that affect the rate or speed of chemical reactions without being altered themselves

enzymatic proteins

cause an increase in cellular activity that in turn causes biochemical reactions to occur more rapidly to meet the needs of the cell

enzymes

quality control looks at ______

equipment

When the attenuated x-ray beam leaves the patient, the remaining x-ray beam is referred to as ______ or ______

exit radiation, remnant radiation

X-rays are attenuated ______ and generally reduced by approx. _____ for each 4 to 5 cm of tissue thickness

exponentially, 50%

matter that intercepts radiation and absorbs part or all of it is said to be this

exposed or irradiated

largest number of repeat exams are due to this type of artifact

exposure

motion, patient artifacts, and quantum mottle are examples of this type of artifact

exposure

how does AEC work?

exposure ends once a certain radiation level reaches the image receptor

A measurement of the amount and energy of the x-rays reaching an area of the film

exposure intensity (or intensity of radiation exposure)

What are the 2 principal measurements involved in sensitometry

exposure to the film, percentage of light transmitted through the processed film

this does not affect the rate of radioactive decay

external factors (ie. heat, high pressure, strong magnetic fields)

the time it takes to end an exposure is termed this

extinction time

a capacitor discharge system in which the exposure begins at maximum mA, and the mA drops as the anode heats.

falling-load generator

T/F: If a scattered photon strikes the image receptor it contributes useful information about the anatomic area of interest

false

T/F: If all other factors remain the same, increasing the exposure intensity will decrease the optical density

false (increasing exposure intensity will increase OD)

T/F: Quantity has more effect on the brightness of a digital image because of computer processing

false (it has less effect)

T/F: Proper film processing is not required for optimal image receptor contrast

false (it is required for optimal contrast)

T/F: A smaller bit depth allows a greater number of shades of gray to be displayed

false (larger bit depth = more shades of gray)

T/F: Fewer x-rays are needed to produce a radiographic image for a thicker anatomic part

false (more are needed for thicker, less are needed for thinner)

T/F: Radiographic images of objects are never magnified in terms of the true object size

false (they are always magnified)

T/F: Film graininess and screen structure mottle are the result of using the wrong technique

false (they are inherent to the screen-film image receptor and are not under the control of the radiographer)

The stem cells of the ovaries multiply during _______.

fetal growth

physicists use this term to describe the interactions among different energies, forces, or masses that can otherwise be described only mathematically

field

this circuit provides electrons for tube current

filament

where electrons are boiled off

filament

a step down transformer is used in what part of the circuit?

filament circuit

the focal spot selector is located in this portion of the x-ray circuit

filament circuit

where would a step down transformer be located in an x-ray circuit?

filament circuit

This controls the filament temperature

filament current

X-ray tube current is adjusted by controlling the _______ _________.

filament current

Name the 2 primary parts of the cathode:

filament focusing cup

this determines the number of electrons emitted by the filament

filament temperature

What are 5 types of image receptors

film and intensifying screens, CR cassettes, indirect DR panels, direct DR panels, fluoroscopy image intensifiers

____ refers to the distribution in size and space of silver halide grains in the film emulsion

film graininess

developed in 1898 by Thomas Edison

fluoroscopy

the production of continuous x-ray images in real time using a special x-ray imaging system, the fluoroscope, with continuous low mA

fluoroscopy

The _________ is the source of radiation in the x-ray tube.

focal spot

where electrons strike the target to make x-rays

focal spot

____ is caused by the effective size of the focal spot

focal-spot blur

what keeps the electrons together in a cloud near the filament

focusing cup

Scatter radiation creates unwanted exposure on the image called ____

fog

The development of silver grains in the film emulsion that contain no useful information

fog density

mass x distance

force

Measurement standards of work is:

force applied on an object over a distance

____ refers to images that appear shorter than the true objects

foreshortening

RF is identified by its

frequency

RF is identified by:

frequency

number of wavelengths that pass a point of observation per second

frequency

rate of rise and fall of a sine wave

frequency

the number of wavelengths passing a point per second

frequency

the number of wavelengths that pass a point of observation per second

frequency

The important properties of the sine wave model of electromagnetic energy:

frequency (f) and wavelength (represented by the Greek letter lambda)

List the 4 properties of electromagnetic energy:

frequency wavelength velocity amplitude

List the 4 properties of photons:

frequency wavelength velocity amplitude

What are the methods of electrification?

friction, contact, and induction

a form of voltage rectification that rectifies the entire AC waveform

full-wave rectification

What type of voltage generation is used in almost all stationary x-ray imaging systems?

full-wave rectification or high-frequency voltage generation

how does something become electrified?

gains excess electrons

the type of radioactivity that has no mass or charge

gamma rays

these come from inside the nucleus of a radioactive atom

gamma rays

this type of radioactivity is hard to stop

gamma rays

a specific sequence of base pairs in a chromosome

gene

device that uses mechanical motion to create electrical energy

generator

segments of DNA that serve as the basic units of heredity

genes

All our genes together are known as our ________.

genome

individual male and female reproductive cells

germ cells

In Roentgen's time, what was used instead of an image receptor?

glass plates

the primary energy source for the cell

glucose

The occupational risk for monitored radiographers may be compared with occupational risk for persons employed in other industries generally considered safe such as:

government and trade

a major source of radon

granite

Si unit of radiation in air

gray in air

In digital imaging, the number of different shades of gray that can be displayed is called

grayscale

The fewer the photons reaching the imaging receptor to form the image, the ____ the quantum mottle visible on the digital image

greater (and vice versa, more photons = less mottle)

What is the result of less voltage ripple?

greater radiation quantity and quality

How hot did the overheated coolant get in the Three Mile Island disaster?

greater than 5000 degrees F

person noted as describing atoms as being made of four different elements in varying quantities (earth, water, air, and fire)

greeks

x-ray tubes that are designed to be turned on and off very rapidly

grid-controlled tubes (ex: portable capacitor discharge imaging systems, digital radiography & cineradiography)

This timer will terminate an exposure after a prescribed time, usually approximately 6 s.

guard timer

artifact that is evenly spaced parallel to the path of film travel

guide shoe mark

In radiography, the quality of x-rays is measured by the

half value layer (HVL)

the best method for specifying x-ray quality

half value layer (HVL)

the thickness of absorbing material necessary to reduce the x-ray intensity to half of its original value

half value layer (HVL)

kink marks, static, and cassette marks are examples of this type of artifact

handling and storage

classifications of artifacts

handling/storage, processing, exposure

Adding filtration is sometimes called this because of the relative increase in average energy.

hardening the x-ray beam

What is the material that is sometimes used for special purpose tubes, such as those used in mammography?

beryllium (Z=4)

type of radioactivity that consists of a particle that is the same as an electron

beta particles

What is the turns ratio of a high-voltage transformer?

between 500:1 and 1000:1

a step up transformer is used in what part of the circuit?

between low and high voltage/between primary and secondary sides

Where is the prereading voltmeter located?

between the autotransformer and high-voltage transformer

Where is the timer located?

between the autotransformer and the high-voltage transformer

where would a step up transformer be located in an x-ray circuit

between the primary and secondary sides

as the angle of a target gets bigger, the effective focal spot will get ______

bigger

each electron shell is representative of this within the atom

binding energies of electrons

the term applied to the chemistry of the body

biochemistry

Each pixel also has a _______, or number of bits that determines the amount of precision in digitizing the analog signal and the number of grays that can be displayed in the image

bit depth

The dark densities on a processed film are created when the exposed crystals are converted to

black metallic silver

People who were employed painting radium watch dials later showed excess risk for _____ cancer.

bone

The resultant x-rays are called ______________ x-rays because they are produced by the slowing (braking) of projectile electrons.

bremsstrahlung

continuous x-ray emission spectrum is from _____ radiation

bremsstrahlung

interaction at the anode where electron interacts with nuclear field and slows

bremsstrahlung

____ is the amount of luminance (light emission) of a display monitor

brightness

Quantum mottle (noise) is visible as _____ or _____ fluctuations on the image

brightness, density

Visibility of the recorded detail refers to ____ or _____

brightness, density

Because of variations in power distribution to the hospital and in power consumption by various sections of the hospital, how much may the voltage provided to an x-ray unit vary?

by as much as 5%

How is the x-ray tube current adjusted?

by controlling the filament current

How are x-rays produced?

by the acceleration of electrons from the cathode to the anode - DC (direct current) only

How are fluoroscopic tables identified?

by their degree of tilt

velocity of electromagnetic radiation

c

The Electromagnetic Wave Equation:

c = frequency x wavelength

KE of random motion of molecules

heat

the kinetic energy of electrons is converted into mostly _____ in the x-ray tube

heat

List 3 functions of mineral salts:

help produce energy aid in conduction of nerve impulses *prevention of muscle cramping

Some radiation victims of ____ syndrome may recover completely.

hematologic

The chest is composed of tissues that vary greatly in the way they attenuate the x-ray beam, such as ribs, air filled lungs, and heart, which creates ___ subject contrast

high

A film with only a few densities that have great differences among them is said to have ____

high contrast

this increases the average energy of the beam, increasing forward scatter

high kVp techniques

What reduces quantum mottle

high mAs, low kVp, slower image receptors

what makes a good contrast agent?

high mass density, high atomic number

lose energy more rapidly than low-LET radiation because the produce much more ionization per unit of distance traveled

high-LET radiation

x-rays with high penetrability are termed this

high-quality x-rays

mA meter is located in this part of the x-ray circuit

high-voltage

responsible for increasing the output voltage from the autotransformer to the kVp necessary for x-ray production

high-voltage generator

What are the 3 parts of the high-voltage generator?

high-voltage transformer filament transformer *rectifiers

Numbers ____ than the par speed refer to fast image receptors

higher

The farther to the right a spectrum is, the ______ the effective energy or quality of the x-ray beam.

higher

The larger the area under the curve, the ______ is the x-ray ________.

higher, intensity or quantity

The x-ray beam generated by the circuit with the ________ voltage ripple has the lowest quantity and quality.

highest

Measurement standards of velocity (speed) is:

how fast an object is moving

means "low oxygen"

hypoxic

Differences in brightness or density in a radiographic image is called

image contrast

____ contributes no useful diagnostic information and serves only to detract from the quality of the image

image noise

What do you call the device that receives the radiation leaving the patient

image receptor (IR)

Greater pixel density provides ______ spatial resolution

improved

Where is the filament contained?

in the focusing cup

Where are rectifiers located?

in the high voltage section

Computer processing time, network transmission time, and digital storage space ___ as the matrix size increases

increase

emission spectrum: increasing mAs

increase amplitude

emission spectrum: increase atomic number of target material

increase amplitude and shift to right

emission spectrum: increasing kV

increase amplitude and shift to right

ways to increase efficiency of x-ray production

increase kV, increase atomic number of target material, use equipment with least voltage ripple

as voltage is _____, amperage decreases

increased

What does added filtration result in?

increased HVL

Using a radiographic grid results in:

increased contrast more gray tones on the radiograph *Increased patient dose

What is the result of increased kVp? (pg 157, 2nd paragraph)

increased quality, HVL, and a more penetrating x-ray beam

Using the magnification mode in flouroscopy _______ patient dose.

increases

When photo wavelenghts decrease what happens to photo energy?

increases

With increasing kVp, the efficiency of x-ray production does this

increases

as the frequency of a photon increases, the energy of the photon _____

increases

increases in atomic number of the absorber _____ photoelectric interactions

increases

increases in mass density of the absorber _____ Compton and Photoelectric interactions

increases

As SID ____, size distortion decreases and as SID ____, size distortion increases

increases, decreases

The efficiency of x-ray production is _______ of the tube current.

independent

Anode angel and heel effect is directly or indirectly proportional

indirectly

the ability to transfer energy from one object to another without touching

induction

the x-ray tube is an example of this type of motor

induction

consists of photons with wavelengths longer than those of visible light but shorter than those of microwaves

infrared light

When the excited outer-shell electrons return to their normal energy level, what type of radiation do they emit?

infrared radiation

sunlight contains these 2 types of invisible light:

infrared ultraviolet

List 3 types of filtration

inherent added *compensating filters

filtration of useful x-ray beams provided by the permanently installed components of an x-ray tube housing assembly and the glass window of an x-ray tube

inherent filtration

What are the 2 components of filtration of diagnostic x-ray beams?

inherent filtration added filtration

What is the principal disadvantage of a three-phase x-ray apparatus?

initial cost

the time it takes to start an exposure is termed this

initiation time

During photoelectric absorption an electron is ejected from the _____ shell and is replaced by an electron from a(n) ______ shell

inner, outer

materials that do not have any free electrons & do not make good conductors for electrical currents

insulators

determining the total number of x-rays emitted from an x-ray tube by adding together the number of x-rays emitted at each energy over the entire spectrum

integration

To reduce patient exposure, the film is placed between 2 _______, which convert the exit radiation intensities into visible light that exposes the crystals in the emulsion

intensifying screens

Where does lower-energy electromagnetic radiation interact?

interacts with molecules, cells, and larger objects in a way that will usually elevate the temperature of the object

natural metabolites such as potassium-40

internally deposited radionuclides

How are frequency and wavelength related?

inversely

How is electromagnetic energy (radiation) intensity related to the square of the distance from the source?

inversely

Latitude and contrast are ____ proportional

inversely

X-ray intensity varies _______ with the square of the distance from the x-ray tube target.

inversely

frequency is _______ proportional to wavelength

inversely

What is the relationship between x-ray energy and its wavelength?

inversely proportional

at a given velocity, wavelength and frequency are:

inversely proportional

for electromagnetic energy, frequency and wavelength are:

inversely proportional

electron removed from atom and atom it originated from

ion pair

the ejected electron and the resultant positively charged atom

ion pair

What is the actual giving up or taking on of electrons causing the atom to assume a net charge (positive or negative)

ionization

The negative side of the x-ray tube is called ______ and has two main parts __________ and __________.

cathode, filament, focusing cup

The smallest unit of protoplasm capable of independent existence is the ______.

cell

Name some uses of microwaves:

cell phone communication highway speed monitoring medical diathermy hot dog preparation

What was substituted for glass when radiologists began using film?

cellulose nitrate

removal of an electron from an atom

ionization

the removal of an electron from an atom

ionization

pairs of small, hollow, cylindrical structures believed to play a part in the formation of the mitotic spindle during cell division; contain the centrioles

centrosomes

prupose of a transformer

change electric potential intensities

Faraday's experiments proved that a current could be induced by a magnetic field only if the field is:

changing.

discrete portion of x-ray emission spectrum is from _____ radiation

characteristic

interaction at the anode where electron interacts with inner shell electron

characteristic

two interactions that occur at the anode to produce radiation

characteristic and bremsstrahlung

The relationship between optical density and radiation exposure is called

characteristic curve

new substance that is formed when two or more atoms of different elements combine

chemical compound

The Z number determines this about the atom

chemical element

Low doses of radiation have been shown to cause _________.

chromosome damage

tiny rod-shaped bodies composed of protein and DNA

chromosomes

interaction where no ionization takes place and results in an atom releasing an energy photon of equal energy in a different direction

coherent

no ionization takes place in which of the radiation interactions with matter

coherent

five interactions in matter

coherent scatter, compton scatter, photoelectric absorption, pair production, photodisintegration

the procedure of confining the x-ray beam to the area of anatomic interest to limit patient radiation dose

collimation

List 8 physical properties of elements that describe the material as it is

color brittleness malleability electrical conductivity density hardness melting & boiling temperature tendency to dissolve in liquids

unit of electric charge

coloumb

used to change DC to AC in a motor

commutator ring

used to make a uniform density on a radiograph for a non uniform part thickness

compensating filter

any quantity of one type of molecule

compound

What increases as the number of x-rays in the beam increases?

ionization of air increases

any electromagnetic or particulate radiation that has sufficient energy to remove an electron from an atom

ionizing radiation

backscatter is caused by this interaction

compton

interaction responsible for occupational dose

compton

What are the 2 types of digital radiographic systems in use today

computed radiography (CR), digital radiography (DR)

electric charge distribution is ______________ in a conductor

concentrated along the sharpest curvature

any type of radiation that is capable of removing an orbital electron from the atom with which it interacts

ionizing radiation

What material that allows the free flow of electrons?

conductor

materials that have free electrons & allow electrical current to flow easily

conductors

Electrification can be created by these 3 methods:

contact friction *induction

Brems x-rays have _______ emission spectrum.

continuous

an uninterrupted (continuous) ordered sequence

continuum

an uninterrupted continuous ordered sequence

continuum

A system that can digitize a greater number of shades of gray has better ________

contrast resolution

The ability of an imaging receptor to distinguish between objects having similar subject contrast is called

contrast resolution

What is anode mode of ?

copper and molybdenum metal

Name the 3 most common anode materials:

copper molybdenum *graphite

particulate and electromagnetic radiation emitted by the sun and stars

cosmic rays

List several drawbacks of film-screen imaging

costs (film, equipment, processing, maintenance), chemical processing, artifacts from handling and processing, required frequent quality control procedures, image cannot be adjusted, cannot be electronically stored, duplicated, displayed, or transmitted, archives consume significant space, easy to lose films

the fundamental unit of electric charge

coulomb

electrostatic force is directly proportional to the product of the electrostatic charges and inversely proportional to the square of the distance between them

coulomb's law

Once a radiographer declares her pregnancy, she will receive _______ and _________.

counseling...and an additional dosimeter

a single excessive exposure will damage the x-ray tube in this way

cracking of the anode

The film emulsion is made of

crystals suspended in gelatin

unit for radioactivity

curie

site of all metabolic functions of the cell

cytoplasm

damages living systems by ionizing (removing electrons from) the atoms comprising the molecular structures of these systems

ionizing radiation

atom with same atomic number but different atomic mass numbers

isotope

atoms that have the same number of protons but differ in the number of neutrons; they behave in the same way during chemical reactions

isotopes

When x-rays are produced, how are they emitted?

isotropically, with equal intensity in all directions

What does added filtration do?

it attenuates x-rays of all energies emitted, but it attenuates a greater number of low-energy x-rays than high-energy x-rays

the discovery of the neutron explained this

it explained the large masses of the elements compared to their number of charges

energy of a photon is directly proportional to

it frequency

When the voltage is increased, what happens to the current?

it is decreased proportionately

List the reasons aluminum is usually chosen as the material for an x-ray filter:

it is efficient in removing low-energy x-rays through the photoelectric effect it is readily available inexpensive it is easily shaped

When the voltage is decreased, what happens to the current?

it is increased proportionately

What is the advantage of adding filtration to the useful x-ray beam?

it reduces patient dose

With age, does inherent filtration tend to increase or decrease? ...why?

it tends to increase because some of the tungsten metal of both target and filament is vaporized and is deposited on the inside of the window (tube tanning)

SI unit for work

joule

energy is expressed in

joules

the way in which a unit of energy is measured in the International System (SI)

joules (J)

unit of measurement for electricity

joules or electron volts

The average energy of an x-ray beam is expressed as ___

kEv

What determines the quality of the x-ray beam

kV

differential absorption is dependent upon this

kV, Z number, mass density

controlling factors of beam quality

kV, filtration

controlling factors of beam quantity

kV, mAs, filtration

Our primary method of controlling contrast is

kVp

Quality is determined by _____

kVp

this determines the quality of the x-ray beam

kVp

What is the unit of measure of the secondary voltage?

kVp (kilovolt peak)

Name the factors that affect x-ray quality

kVp Filtration

x-ray quantity is proportional to...

kVp^2

LET is usually described in what unit over what length?

keV per micron

When the electron from the filament interact with the anode the __________ energy of the electrons are converted to ___% of ______energy and ___% of ________energy

kenetic, 99, heat, 1, x-ray

SI unit for mass

kg

Measurement standards of mass is:

kilogram

the scientific unit of mass

kilogram

unit of mass

kilogram (kg)

unit of measure that is the mass of 1000 cm^3 of water at 4 degrees C.

kilogram (kg)

the energy of motion and the function of an object's mass and velocity

kinetic energy

artifact caused by sharp bending/creasing of the film

kink mark

wavelength is represented by this greek letter

lambda

In the straight-line portion of a characteristic curve, small changes in exposure result in _____ changes in OD

large

Digital image quality is improved with a ____ matrix size that includes a ____ number of smaller pixels

larger, larger

The radiation that exits the patient interacts with the image receptor to form the _____ image, which must be processed to be visible

latent

There is usually a ____ before the symptoms of acute radiation syndromes appear.

latent period

The range of exposures over which the image receptor responds with ODs in the diagnostically useful range

latitude

The shorthand for determining speed is to choose the one on the ____

left

What is the maximum leakage allowed from the x-ray tube housing?

less than 100 mR/hr at 1 meter from the source

High speed IRs require ____ exposure (mA) which results in fewer x-ray photons being able to produce ______ scatter, decreasing personnel exposure.

less; Compton

Ankylosing spondylitis patients treated with radiation showed an increased incidence of ______.

leukemia

One major deficiency of film-screen imaging is

limited dynamic range

measures the voltage provided to the x-ray imaging system and adjusts that voltage to precisely 220V

line compensator

The x-ray intensity is lower on the anode side of the tube because of the _____.

line focus principle

varying power supplies to the x-ray circuit will be corrected by what component of the circuit?

line voltage compensator

today, these make it possible to produce x-rays of considerably higher energies than gamma ray emissions

linear accelerators

Studies of A-bomb survivors indicate that leukemia has a _______ dose-response relationship to radiation..

linear, nonthreshold

mAs is directly related to output intensity

linearity

TLDs contain the sensing material, _______, which responds to ionizing radiation in a similar manner as _____.

lithium fluoride; human tissue

Exposure values for a characteristic curve are presented in a _______ fashion

logarithmic

Which contrast scale is generally considered to be the most useful in diagnostic radiography because it offers more information and demonstrates many different tissues at once

long scale (low contrast)

What are several terms used for a large number of narrowly varying tonal values

long scale, low contrast, elephant

Low contrast is also called

long-scale contrast

What overall effects do Compton scattering have on an x-ray photon

loss of energy and change of direction

The abdomen is composed of tissues that attenuate the x-ray beam similarly, such as the stomach, kidneys, intestines, and pancreas, which creates ___ subject contrast

low

circuits on the operating console are _____ voltage

low

A film with a large number of densities that vary only a little is said to have ____

low contrast

Point mutations commonly occur with ________ radiation.

low-LET

Point mutations commonly occur with this type of radiation

low-LET radiation

Elements of low atomic number produce ________ characteristic x-rays.

low-energy

x-rays with low penetrability are termed this

low-quality x-rays

kVp meter is located in this part of the x-ray circuit

low-voltage

Numbers ____ than par speed refer to "detail" image receptors

lower

The most radiosensitive cells in the hematopoietic system of the human body are the _____.

lymphocytes

white blood cells involved in the body's immune reactions

lymphocytes

these are called suicide sacks

lysosomes

SI unit for velocity

m/s

SI unit for acceleration

m/s(squared)

The quantity of x-rays in the primary beam is controlled by the ____

mA

What is the unit of measure of the secondary current?

mA (milliamperes)

Placed in the tube circuit, connected at the center of the secondary winding of the high-voltage step-up transformer in series with the x-ray tube. This reduces the possibility of shock.

mA meter location

For three-phase and high-frequency, kW =

mA x kVp / 1000

Quantity of radiation is determined by ____

mA x time (mAs)

Doubling the exposure can be achieved by doubling the ____

mAs

When SID is increased, what must be increased by SID^2 to maintain constant exposure to the image receptor?

mAs

a measure of the total number of electrons that travel from cathode to anode to produce x-rays

mAs

beam quantity is directly proportional to

mAs

What provides the safest tube current in the shortest time possible?

mAs Timer

Name the factors the affect X-ray quantity

mAs kVp Distance Filtration

monitors the product of mA and exposure time and terminates exposure when the desired mAs value is attained

mAs timer

used on falling-load and capacitor discharge imaging systems

mAs timers

What are the five factors that affect the x-ray emission spectrum?

mAs, kVp, Added filtration, Target material, and Voltage waveform.

a measure of the number of ion pairs produced in air by a quantity of x-rays

mGya

Quantity is expressed in _____

mR

Name 3 ways to express x-ray intensity

mR/s mR/min. *mR/mAs

leaves the cell nucleus and directs the process of making proteins out of amino acids in the cytoplasm

mRNA

Energy field surrounding an electrical charge in motion is called what?

magnetic field

What can magnetize a ferromagnetic material, such as iron?

magnetic field

induction motors use this to operate

magnetic field

ability of a material to attract the lines of magnetic field intensity

magnetic permeability

Every magnet has a north and south pole which these poles are called what?

magnetic poles

degree to which material can be magnetized

magnetic susceptibility

Magnification is expressed by the

magnification factor (MF)

Radiographic examinations where magnification is desirable and is carefully planned into the examination is called

magnification radiography

List the 3 geometric factors that affect radiographic quality

magnification, distortion, focal-spot blur

the quantity of matter as described by its energy equivalence

mass

this is determined by the object's energy equivalence

mass

base quantities in mechanical physics

mass, length, time

basic quanities in mechanical physics

mass, length, time

A digital image is recorded as a ____ or combination of rows and columns of pixels

matrix

anything that occupies space; the material substance with mass of which physical objects are composed

matter

has mass and energy equivalence; may also have electric charge

matter

the strangest property associated with matter and energy

matter and energy are interchangeable

What is a radiographic rating chart used for?

maximum exposure times

high-voltage generator power =

maximum x-ray tube current (mA) at 100 kVp and 100 ms

What contributes to the increased usage of medical radiation exams?

medicolegal considerations - physicians relying more on radiological diagnoses to assist them in patient care

Measurement standards of length is:

meter

SI unit for length

meter

unit of measure based on the speed of light

meter

unit of measure that is based on the speed of light

meter

The size of a pixel is measured in ____ (0.001 mm)

microns

these frequencies vary according to use but are always higher than broadcast RF and lower than infrared

microwave frequencies

very-short-wavelength RF

microwave radiation

the x-ray tube current, crossing from cathode to anode, is measured in this unit of measure:

milliamperes (mA)

the result of a falling load generator

minimum exposure time

____ artifacts are of less density than the area of the image immediately surrounding them

minus-density

"Powerhouse of the cell" ("Power Plant") that supplies energy for the cell; the greatest number of these are found in cells exhibiting the greatest activity

mitochondria

the powerhouse of the cell

mitochondrion

When two or more atoms are chemically united, they form a what?

molecule

smallest particle of a compound

molecule

combination of two or more types of atoms of various elements

molecules

Digital image receptors are _____ sensitive to scatter radiation than film because they can detect low levels of radiation intensity

more

Voltage waveforms of three-phase or high-frequency operation result in _____ _______ x-ray emission than those of single-phase operation.

more intense

When there is ____ forward scatter and ____ side scatter, chances of occupational exposure will be reduced.

more; less

What is the number one enemy of recorded detail

motion

The loss of radiographic quality due to movement of the patient or the x-ray tube during exposure is called

motion blur

device that uses electrical energy to create mechanical motion

motor

1/1000 of a rem

mrem

Give an example of a golgi apparatus product:

mucus

Transformers operates on the principle of mutual induction or self induction?

mutual induction

Two main categories of radiation

natural environmental radiation & man-made radiation

electrical charge of an electron

negative

In their normal state, atoms are electrically...

neutral

British units of weight

newton and pound

A change in kVp has ___ effect on the position of the discrete x-ray emission spectrum.

no

Can grid be used to prevent off focus radiation from reaching the film?

no

The radiographic beam should be collimated so that it is:

no larger than the image receptor

Skin effects from localized doses of radiation follow a _______ dose-response relationship.

non-linear, threshold

How many excess cancer deaths are expected in the future due to the Three Mile Island accident?

none

Death from acute radiation exposure follows a ____, ____ dose-response relationship.

nonlinear, threshold

If the object plane and the image plane are _____, distortion occurs

not parallel

the energy required to hold nucleons together as a nucleus

nuclear binding energy

an example of converting matter into energy

nuclear fission

the basis for generating electricity

nuclear fission

these are composed of quarks that are held together by gluons

nucleons (protons and neutrons)

smaller structures that make up nucleic acids

nucleotides

gamma rays are produced in this part of the atom

nucleus

If the image size, SID, and SOD are known, the object size can be calculated as

object size = image size x SOD/SID (image size times SOD over SID)

Distortion depends on what 3 things

object thickness, object position, object shape

How is an object charged?

objects are charged by adding or removing electrons

unit of electric resistance

ohm

serves as both an insulator against electric shock and as a thermal cushion to dissipate heat

oil contained in the protective housing

Where is the mAs timer located?

on the secondary side of the high-voltage transformer

the atomic mass # of each type of nucleon is

one (1)

the distance traveled by light in 1/299,792,468 second

one meter

Which x-rays of tungsten are the only ones useful for imaging?

only the K-characteristic x-rays

The numeric calculation that compares the intensity of light transmitted through an area on the film to the amount of light originally striking the area

optical density

xrays are produced in this part of the atom

orbital shells

when you check a radiologist report for actually matching the patient's diagnosis

outcome assessment

what part of the image intensifier changes electrons into light photons?

output phosphor

The presence of ______ in biologic tissues makes the damage produced by free radicals permanent.

oxygen

an example of converting energy into mass

pair production

When expressing speed as a number, 100 is called the

par speed

Which type of circuit do the following laws apply: total R=1/R1+1/R2+1/R3; total I= I1+I2+I3; total V=V1=V2=V3

parallel

x-rays behave as though they are

particles

What advantage does increasing kVp by 15% and reducing the mAs by half have?

patient dose is reduced significantly

What is increased as the energy of an x-ray beam is increased?

penetrability

refers to the ability of x-rays to penetrate deeper in tissue

penetrability

kVp settings on teh operator console controls this in the x-ray beam

penetrability/energy of the beam

Quality is energy, is _____, is electromotive force

penetrating ability

What is visibility dependent on

penetration, density (brightness), contrast

The blurred outer portion of the image is called the ____

penumbra

quality assurance looks at ______

people

The presence of oxygen in biologic tissues makes the damage produced by free radicals _______ because oxygen reacts w/free radicals to produce __________ compounds.

permanent....peroxide

What part of the image intensifier changes light photons into electrons?

photocathode

interaction responsible for patient dose

photoelectric

Which interaction creates the white or clear areas (more brightness or low density) on the image

photoelectric absorption

What is the complete absorption of an x-ray and ejection of an electron called if it occurs in the diagnostic range

photoelectric effect

During complete absorption, what is the ejected electron called

photoelectron

any quantum of electromagnetic radiation

photon

smallest part of electromagnetic energy

photon

the smallest quantity of any type of electromagnetic energy

photon

the smallest quantity of any type of electromagnetic radiation; it may be pictured as a small bundle of energy, sometimes called a quantum

photon

How is the energy of a photon related to its wavelength?

photon energy is inversely proportional to photon wavelength

artifact that repeats every 3.14" perpendicular to the path of film travel

pi line

tool to measure focal spot size

pin hole camera, star pattern, slit camera

The number of pixels per unit area

pixel density

The distance measured from the center of a pixel to an adjacent pixel

pixel pitch

___ artifacts are greater in density than the area of the image immediately surrounding them

plus-density

What are the two classifications of artifacts

plus-density, minus-density

electrical charge of a proton

positive

Positively charged beta particle

positron

what does voltage measure?

potential energy

rate of doing work

power

the product of voltage and current; expressed in Watts

power

Give an example of a source of alternating current:

power plants a wall plug outlet

the kV meter is on the ____ side of the x-ray circuit

primary

Film must be _____ before it is looked at

processed chemically

emulsion pickoff, curtain effect and chemical fog are examples of this type of artifact

processing

Immediately following a whole body dose of 1000 rads, the victim would experience ______.

prodromal symptoms

Electrons traveling from cathode to anode constitute the x-ray tube current and are sometimes called this:

projectile electrons

A change in mA or mAs results in a ________ change in the amplitude of the x-ray emission spectrum at all energies.

proportional

guards against excessive radiation exposure and electric shock

protective housing

essential for growth, the construction of new body tissue, and the repair of injured or debilitated tissue

proteins

the most elementary building blocks of cells

proteins

the smallest unit of positive charge

proton

List the 3 fundamental particles of an atom

protons neutrons *electrons

the chemical building material for all living things

protoplasm

What do you call the penetrating ability of the x-ray beam

quality

The primary factor that affects the amount of brightness or density produced in an image is the ____ of radiation reaching the image receptor

quantity (amount)

mA setting on the operator console controls this in the x-ray beam

quantity of electrons emitted through thermionic emission

a term that means "a small bundle of energy"

quantum

details of atomic structure are most accurately described by this atomic model

quantum chromodynamics (QCD)

____ refers to the random nature by which x-rays interact with the image receptor

quantum mottle

Radiographic mottle is made up of what 4 things

quantum mottle, film granularity, screen structure mottle, scatter radiation

unit for patient dose

rad

how does an x-ray tube cool primarily (what method is used)?

radiation

the transfer of energy

radiation

the transfer of energy from one area or medium to another

radiation

the branch of biology concerned with the effects of ionizing radiation on living systems

radiation biology

the amount of energy transferred to electrons by ionizing radiation

radiation dose

demonstrated graphically through a curve that maps the observed effects of radiation exposure in relation to the doses of radiation received

radiation dose-response relationship

What is another name for x-ray intensity or x-ray quantity?

radiation exposure

What do scattered photons contribute to if they do not strike the image receptor

radiation exposure (to the patient if they don't leave the patient and anyone nearby if they do leave the patient)

The amount of optical density created on the film after processing is primarily determined by

radiation exposure to the image receptor

A growing body of radiobiologic evidence suggests that a little bit of radiation is good for you. A little radiation may stimulate hormonal and immune response to other toxic environmental agents. We refer to this as _______.

radiation hormesis

A theory which presents low doses of radiation providing beneficial health effects is:

radiation hormesis

refers to the penetrability of the x-ray beam and is expressed in kVp or HVL

radiation quality

refers to the number of x-rays or the intensity of the x-ray beam & is usually expressed in mR or mR/mAs

radiation quantity

Although the computer can adjust for low and high exposure technique errors, the ____ is still responsible for selecting techniques that produce acceptable image quality while maintaining patient exposure as low as reasonably achievable

radiographer

Factors that affect x-ray beam quality also influence this

radiographic contrast

____ is the umbrella term for the amount of noise seen in an image

radiographic mottle

The two general types of x-ray exams

radiography and fluoroscopy

structures that transmit x-rays are called this:

radiolucent

structures that absorb x-rays are called this:

radiopaque

the first decay product of radium

radon

the largest source of natural environmental radiation

radon

Measurement standards of acceleration is:

rate of change of speed per unit of time

Measurement standards of power is:

rate of doing work (measured in watts)

Magnification is calculated as the

ratio of image size to object size (MF=image size/object size)

same mAs selected with different mA stations should still yield the same mR

reciprocity

The law that states that the OD will be the same if the mAs value is constant regardless of the exposure time

reciprocity law

An image with increased contrast resolution increases the visibility of ____

recorded detail

___ refers to the distinctness or sharpness of the structural lines that make up the recorded image

recorded detail

process of converting AC to DC

rectification

the process of converting AC to DC

rectification

these convert AC to DC

rectifiers

Anything that you do to ____ ____ when taking a radiograph, will also lower occupational exposure.

reduce scatter

What technique should be used to maintain a constant exposure of the image receptor and constant radiographic optical density if kVp is increased by 15%?

reduce the mAs by 1/2

What is the disadvantage of increasing kVp by 15% and reducing the mAs by half?

reduced image contrast

What is the disadvantage of x-ray beam filtration?

reduced image contrast caused by beam hardening

Adding filtration to an x-ray tube results in ______ x-ray intensity but ______ effective energy.

reduced, increased

When distance is doubled, intensity of x-ray beam is ______ by _______.

reduced; factor of four

return or reentry of an x-ray

reflection

the deviation in the course of visible light when they pass from one transparent medium to another

refraction

What is the traditional unit of measure for Equivalent Dose (EqD)?

rem

unit for occupational dose

rem

the unit of occupational radiation exposure

rem or (Sv)

The light or clear areas on the film result from _____ during processing

removal of unexposed crystals

A _______ looks at repeated radiographs to determine the cause of repeat.

repeat analysis program

like charges

repel

which system of the processor allows for chemistry to stay fresh?

replenishment

same mAs used on the same tube should yield the same mR output

reproducibility

The ability to image 2 separate objects and visually distinguish one from the other

resolution

What are 3 interrelated characteristics of radiographic quality

resolution, noise, speed

Limiting _____ limits occupational exposure.

retakes

unit for radiation in air

roentgen

Radiation exposure is measured in this:

roentgens (R)

rating charts for x-ray tubes demonstrate this

safe exposure times

Filament current that has risen to its maximum value because all available electrons have been used is called?

saturation current

filament current that has risen to its maximum value because all available electrons have been used

saturation current

Radiographic film images are typically described by their _____, or the range of densities visible

scale of contrast

our greatest source of radiation exposure

scatter radiation

In which type of interaction are incoming photons not absorbed but instead lose energy during interactions with atoms comprising the tissue

scattering

___ is similar to film graininess but refers instead to the phosphor of the radiographic intensifying screen

screen structure mottle

Measurement standards of time is:

second

SI unit for time

second

the standard unit of time based on the vibration of atoms of cesium

second (s)

the mA meter is on the ____ side of the x-ray circuit

secondary

mRNA transfers its genetic code to ____.

tRNA

Anatomic tissues are typically ranked based on their attenuation properties. List the following substances in order from most radiopaque to most radiolucient: fat, bone, air, muscle, and teeth

teeth, bone, muscle, fat, air

which system monitors and adjusts the temperature of the processor chemistry?

temperature control system

results from deposits of uranium, thorium, and other radionuclides in the Earth

terrestrial radiation

What does the kinetic energy formula indicate about the relationship between mass & velocity?

that the velocity is much more important than mass

the first heated filament x-ray tube was developed by a physicist, William Coolidge, in 1913

the Coolidge Hot Cathode Tube

Compensating for a change in SID by changing mAs by the factor SID^2 is known as

the Square Law

the first ancient people to describe photons

the ancient Greeks

Name the positive side of the x-ray tube:

the anode

conducts electricity and radiates heat and contains the target

the anode

List the internal structures of the x-ray tube:

the anode the cathode

In a graph, the total number of x-rays emitted is equivalent to...

the area under the curve of the x-ray emission spectrum

What determines the chemical properties of an element?

the arrangements of electrons in the outermost shells

the basic building block of matter

the atom

the building block of the radiographer's understanding of the interaction between ionizing radiation and matter

the atom

the superscript in each block of the Periodic Table of Elements represents this

the atomic number

What unique characteristic of the TLD dosimeter makes it the most reliable?

the atomic number of lithium fluoride is most similar to human tissue

this has a single winding and is designed to supply a precise voltage to the filament circuit and to the high-voltage circuit of the x-ray imaging system

the autotransformer

Name the 2 primary parts of the diagnostic x-ray tube:

the cathode and the anode

method of displaying the sensitivity of a particular type of cell to radiation

the cell survival curve

What determines the type of ER in a cell?

the cell type

What is responsible for most of the heat generated in the anodes of x-ray tubes?

the constant excitation & return of outer-shell electrons

the fundamental unit of electric charge

the coulomb

The characteristic x-ray has energy equal to this:

the difference in the binding energies of the orbital electrons involved

What helps shield the earth from cosmic rays?

the earth's atmosphere and magnetic field

this governs the interaction of electrostatic charges, the magnetic field, and the interaction of magnetic poles

the electric field

The smallest unit of electric charge

the electron

What is the projectile in an x-ray tube?

the electron

has one unit of negative charge

the electron

unit of energy used to describe x-rays

the electron volt (eV)

the subscript in each block of the Periodic Table of Elements represents this

the elemental mass

What is the main advantage of full-wave rectification?

the exposure time for any given technique is cut in half

the x-ray tube current is controlled through

the filament circuit

this governs the interaction of different masses

the gravitational field

the unit of frequency that is used to describe radio waves

the hertz

Name the 3 primary parts of a high-voltage generator:

the high-voltage transformer the filament transformer *rectifiers

As electron energy is increased, what is also increased?

the intensity (quantity) and the energy (quality) of the x-ray beam

describes the relationship between radiation intensity and distance from the radiation source

the inverse square law

this is placed across the output terminals of the autotransformer, and therefore actually reads voltage

the kVp meter

Planck's constant is symbolized by

the letter "h"

measures the voltage provided to the x-ray imaging system and adjusts that voltage to precisely 220V

the line compensator

Optical density is defined as

the logarithm of the inverse transmittance

1/1000 of a rad, where the rad is 100 ergs of energy absorbed per gram of tissue

the mrad

part of the atom that contains nearly all the mass of the atom

the nucleus

In the Periodic Table, what do the rows relate to?

the number of electron shells present

In the Periodic Table, what do the columns relate to?

the number of electrons in the outermost shell

in the normal atom, the number of electrons is equal to

the number of positive charges in the nucleus

this ultimately determines the chemical behavior of an atom (chemical element)

the number of protons the atom contains

if the count rate has fallen by half, this has also fallen by half

the number of unstable atoms

the count rate coming from a radioactive source depends on the number of this

the number of unstable atoms it contains

What is the primary function of the oil in the high-voltage section of the generator?

the oil is used primarily for electrical insulation

this allows the radiologic technologist to control the x-ray tube current and voltage so that the useful x-ray beam is of proper quantity and quality

the operating console

used to control the voltage applied to the x-ray tube, the current through the x-ray tube, and the exposure time

the operating console

has one unit of positive charge

the proton

Increasing the kVp peak increases...

the quality of an x-ray beam

What does increasing filtration increase?

the quality of an x-ray beam

What does increasing filtration decrease?

the quantity of an x-ray beam

The cumulative effective dose limit for a radiographer cannot exceed:

the radiographer's age x 1rem or age in years x 10mSv

What speed do x-ray photons travel at?

the speed of light

The external structure of the x-ray tube consists of these 3 parts:

the support structure the protective housing *the glass or metal enclosure

the number of electrons emitted by the filament is determined by this

the temperature of the filament

When using AEC, how should the electronic timer be set in case the AEC fails to terminate?

the timer should be set to 1.5 times the expected exposure time as a backup timer in case the AEC fails to terminate

x-rays emitted through the window are called this

the useful beam

this extremely small segment of the electromagnetic energy continuum is the only one that is naturally apparent to us

the visible light segment

Name 3 things the operating console controls:

the voltage applied to the x-ray tube the current through the x-ray tube *the exposure time

Some regions of the EM spectrum behave like waves and some regions behave like particles in their interaction with matter. This phenomenon is called:

the wave-particle duality of EM radiation

this provides for low inherent filtration

the window

the penetrability of an x-ray beam is called this

the x-ray quality

the intensity of the x-ray beam is called this

the x-ray quantity

What is the only difference between the primary and secondary waveforms?

their amplitude

the only difference between atoms of different elements in the late 1800's

their mass

objects in motion have kinetic energy proportional to this

their mass and to the square of their velocity

the only difference between x-rays and gamma rays

their origin

What is the difference between x-rays and gamma rays?

their origin: X-rays are emitted from the electron cloud. Gamma rays are emitted from the nucleus.

The binding energies, or energy levels, of electrons, are represented by

their shells.

cooling charts for x-ray tubes demonstrate this

thermal capacities and heat dissipation characteristics

refers to the "boiling off" of electrons from the filament

thermionic emission

the release of electrons from a heated filament

thermionic emission

the wavelength differences between a photon of x-radiation and a photon of visible light result in this difference between them

these differences result in differences in the way these photons interact with matter

What units, both traditional & SI, are used to measure occupational and non-occupational dose limits?

these dose limits are expressed as EfD, and stated in Sieverts (Sv) and rem

List 3 advantages of carbon fiber tabletops:

they are strong absorb little x-radiation *contribute to reduced patient dose

What is the only way the photons of various portions of the electromagnetic spectrum differ?

they differ only in frequency and wavelength

the ionizing strength of beta particles in comparison with alpha particles

they do around 1/20th of the damage done by the same dose of alpha particles

What happens when the projectile electrons hit the heavy metal atoms of the x-ray tube target?

they transfer their kinetic energy to the target atoms

What factors affect x-ray beam attenuation

thickness, atomic number, and density of the anatomic part and energy of the x-ray beam

The absorption characteristics of the anatomic part are determined by its ____, ____, and ____

thickness, atomic number, tissue density

What tissue characteristics contribute to subject contrast

thickness, density, effective atomic number (same ones that affect attenuation and absorption)

model of atom described similar to plum pudding

thomson's

What are filaments usually made of?

thoriated tungsten

to figure HU for a ______ phase gnerator, multiply 1.4 x kvp x ma x s

three

With this type of power, multiple voltage waveforms are superimposed on one another, resulting in a waveform that maintains a nearly constant high voltage

three-phase power

Radiation induced skin cancer in radiotherapy patients has occurred with a _______ dose-response.

threshold

a point at which a response or reaction to an increasing stimulation first occurs

threshold

People who had radiation treatments to their thymus gland as children later showed excess risk for ______.

thyroid cancers

Name the primary function of an x-ray imaging system

to convert electric energy into electromagnetic energy

What is the important role of neutrophils?

to fight infection

Primary Function of the X-ray Imaging System

to provide a controlled flow of electrons intense enough to produce an x-ray beam appropriate for imaging

the function of the x-ray imaging system:

to provide a controlled flow of electrons intense enough to produce an x-ray beam appropriate for imaging

What is the purpose of the metal filter that is positioned in the useful beam in an x-ray imaging system?

to reduce the number of low energy x-rays

State the primary purpose of adding filtration to an x-ray beam.

to remove selectively low-energy x-rays that have little chance of getting to the image receptor

The bottom portion of a characteristic curve which shows only small change in OD is called the

toe

Individuals that are restraining patients should be positioned so that their _____ is not hit by the primary beam.

torso

transformer uses self induction or mutual induction to _____

transform electrical energy into higher or lower intensities

If the incoming x-ray photon passes through the anatomic part without any interaction, what is it called

transmission (more specifically direct transmission)

The ratio of the 2 intensities used to calculate optical density is called

transmittance

3 degrees of interaction between light and an absorbing material:

transparency (transmission) translucency (attenuation) *opacity (absorption)

what system of the processor gets a film from latent to manifest image?

transport

List 3 functions of water:

transports materials to and from cells acts as a solvent for regulation of acids, bases and salts *maintains body temperature

T/F: A densitometer calculates optical density

true

T/F: A quality radiographic image accurately represents the anatomic area of interest

true

T/F: A radiographic image cannot be an exact reconstruction of the anatomic structure because some information is always lost during the process of image formation

true

T/F: A small anatomic structure is best visualized when its brightness or density varies significantly from the background

true

T/F: Anatomic tissues that vary in absorption and transmission create a range of brightness or shades of gray

true

T/F: Because the digital image is processed and reconstructed in the computer as digital data, its grayscale or contrast can be altered

true

T/F: Each pixel is recorded as a single numeric value, which is represented as a brightness level on a display monitor

true

T/F: In order to evaluate other attributes of radiographic quality, such as contrast and sharpness, the image must have sufficient brightness or density to visualize the anatomic area of interest

true

T/F: Shape distortion can be used to our advantage in particular projections or positions, for example to eliminate superimposition

true

T/F: Speed = 1/exposure in roentgens to produce an OD of 1.0 plus base + fog

true

T/F: The imaging process makes it impossible to produce a radiographic image without some degree of unsharpness (blurring)

true

T/F: The secondary x-ray created during photoelectric absorption has very low energy and is unlikely to exit the patient

true

T/F: Tissue composed of a higher atomic number, such as bone, attenuates the x-ray beam more than tissue composed of a lower atomic number, such as fat

true

T/F: When the image is distorted, spatial resolution or recorded detail is also reduced

true

T/F: X-ray beam attenuation is decreased with a higher energy x-ray beam and increased with a lower energy x-ray beam

true

T/F: the best source for exposure technique is an exposure technique chart made and calibrated for the x-ray unit being used

true

T/F: the quality (contrast) of the radiographic image is compromised if scattered photons strike the image receptor

true

T/F: the various shades of gray recorded in the radiographic image make anatomic tissues visible

true

T/F: If 2 image recepters were compared and A was twice as fast as B, then A would require half the mAs of B to produce a given OD, but the image on A might be of poor quality because of increased radiographic mottle

true (twice the speed requires half the mAs, but faster speed generally creates more noise)

electrons boiled off of the filament and being attracted to tungsten plating the inside of the x-ray tube

tube arcing

What is angled if an image has elongation

tube or IR

What is the most common cause of tube failure?

tube tanning - tungsten vaporization with deposition on the inside of the glass enclosure

Shape distortion occurs when one of these three things are angled

tube, anatomic part, image receptor

What are the filaments made of ?

tungsten

term used to describe the ratio of the number of secondary windings to the number of primary windings

turns ratio

located in the electromagnetic spectrum between visible light and ionizing radiation

ultraviolet light

The detailed, sharp inner portion of the image is called the ___

umbra

Where is the fluoroscopic x-ray tube usually located?

under the examining table

Limited dynamic range makes film very sensitive to ______ and restricts ____

underexposure or overexposure, visibility of structures that differ greatly in x-ray attenuation

electric charge distribuition is ______ in a diffuse nonconductor

uniform

How do you minimize motion blur

use shortest exposure time possible, restrict patient movement, use large SID, use small OID

How do you minimize focal-spot blur

use smallest focal spot, use smallest OID possible, use largest SID possible

How do you minimize magnification

use the largest SID possible, place the object as close to the image receptor as possible

The Wave Equation:

v = frequency x wavelength

an old-fashioned rectifier was called this

valve tube

What is constant with all electromagnetic energies?

velocity

the rate of change of position with time, sometimes called speed

velocity

The 3 wave parameters needed to describe electromagnetic energy:

velocity frequency *wavelength

derived quantities in mechanical physics

velocity, acceleration, momentum, work, volume

The ____ of the anatomic structures and the ____ of their structural lines recorded (sharpness) determine the overall quality of the radiographic image

visibility, accuracy

occupies the smallest segment of the electromagnetic spectrum

visible light

the only portion of the electromagnetic spectrum we can sense directly

visible light

3 regions of the electromagnetic spectrum most important to radiologic science:

visible light x-radiation *radiofrequency

the unit of electric potential

volt

unit of electric potential

volt

this is required to ensure that electrons flow from cathode to anode only

voltage rectification

means of characterizing voltage waveforms

voltage ripple

the fluctuation in the voltage applied to the x-ray tube expressed as a percentage of peak kilovoltage

voltage ripple

What is the unit of measure of the primary voltage?

volts (V)

the step up transformer changes _____ into _____

volts; kilovolts

Name 2 mathematical formulas that describe how electromagnetic energy behaves

wave equation inverse square law

Maximum x-ray energy is associated with the minimum x-ray ________.

wavelength

What is the distance between the peaks of waves called?

wavelength

distance from one crest to another

wavelength

the distance from one crest to another, from one valley to another, or from any point on the sine wave to the next corresponding point

wavelength

visible light is identified by its

wavelength

visible light is identified by:

wavelength

determined by the force of gravity

weight

During the latent period, the radiation victim experiences _____.

well-being

the 4 basic essences the Greek scientists thought that could change the 4 basic substances

wet dry hot cold

When is a small focal spot used?

when better spatial resolution is required

When is a large focal spot used?

when large body parts are imaged, and when other techniques that produce high heat are required

When do photons interact with matter most easily?

when the matter is approximately the same size as the photon wavelength

When does complete absorption occur

when the x-ray photon has enough energy to eject an inner-shell electron

List 6 chemical properties of elements

whether a material will react w/another material rate of reaction with that material Amt of heat produced by the reaction w/material At what temperature it will react In what proportion it reacts Valence of elements

A unique characteristic of digital imaging receptors is their _____ dynamic range

wide

x-rays are emitted through this special section of the x-ray tube:

window

How accurate should the collimator be?

within 2% of SID

the force applied to an object multiplied by the distance over which it is applied

work

Here, the relative number of x-rays emitted is plotted as a function of the energy of each individual x-ray and x-ray energy is the variable that is considered.

x-ray emission spectrum

The minimum wavelength of x-ray emission corresponds to the maximum ______, and the maximum x-ray energy is numerically equal to the __

x-ray energy, kVp

the number of x-rays in the useful beam

x-ray quantity

The 3 Main Components of an x-ray imaging system:

x-ray tube operating console *high-voltage generator

What are the 3 principle parts of the X-ray imaging system?

x-ray tube operating console *high-voltage generator

these are emitted from the electron cloud of an atom that has been stimulated artificially

x-rays

List 2 examples of low LET radiation:

x-rays Gamma rays

What is the charge of an x-ray photon?

x-rays have no electric charge

What is the mass of an x-ray photon?

x-rays have no mass

What is leakage radiation?

x-rays that escape throught the protective covering.

List 3 examples of electromagnetic energy:

x-rays visible light *radiofrequencies

What happens to the x-ray beam when you increase the kV by 15%

you get the effect of the mAs doubling (increase in density)

the atomic mass number of an electron

zero

What is the advantage of having a metal envelope instead of a glass x-ray tube?

• Able to provide constant electric potential between the electrons of the tube current and the envelope. • Have longer life • Less likely to fall

What is the function of protective housing?

• Prevents unnecessary radiation exposure to the patient and radiographer • Protects from electric shock • Provides mechanical support for the tube and protect from damage • Reduces the level of leakage radiation to less than 100 mR/Hr at 1 meter from the tube

What are the two types of anode?

• Stationary anode • Rotating anode

1 Gray is equivalent to

100 rad

What is the usual tube current range for diagnostic x-ray systems?

100 to 1200 mA

Voltage ripple of single-phase generator

100%

What percent voltage ripple does single-phase power have?

100%

The intensity of radiation scattered at 90 degrees at a distance of 1 m from its source is reduced by a factor of ______ relative to the primary radiation for a field size of 8"x8".

1000

instant death of large numbers of cells occurs at this irradiation dose:

1000 Gy

What is the maximum permitted equivalent dose in a controlled area?

1000 microSv (100 mrem)

the associated wavelength for x-ray energy

10^-10 to 10^-14 m

the range of x-ray photon frequency

10^18 to 10^22 Hz

the number of elements that have been identified today

112

Source to skin distance for all mobile exams should not be less than ___ inches.

12 inches

When using a high-frequency generator, how much reduction in kVp would be required to produce the same image receptor exposure when operated at the same mAs as single phase?

12 kVp

minimum source to skin distance for mobile fluoroscopy unit

12"

Effective dose from Nuclear Medicine

12%

To produce results similar to single-phase equipment, a ____ reduction is required on three-phase equipment.

12%

a full wave rectified single phase generator would have how many x-ray beam pulses per second?

120

How many times per second does the voltage swing from zero to maximum potential under single-phase full-wave rectification?

120 times per second

If the peak energy is ____ kVp, the primary protective barrier in a typical installation consists of ___ inch of Pb and extends ___ ft upward from the floor when the x-ray tube is ____ ft from the wall in question.

130; 1/16; 7; 5-7

Voltage ripple of three-phase, six-pulse generator

14%

What percent voltage ripple does three phase, six pulse power have?

14%

Characteristic x-ray emission spectrum for tungsten contains ____ different x-ray energies.

15

Source to skin distance for all exams with stationary x-ray equipment should not be less than _____ inches.

15 inches

Dose limit to lens of eye for occupational workers

15 rem

minimum source to skin distance for stationary/fixed fluoroscopy unit

15"

At 100 kVp, approx. _____ of the x-ray beam is Characteristic, and the remaining is Bremsstrahlung.

15%

What percentage of proteins are contained in the cell?

15%

What is the normal platelet count for adults?

150,000 to 300,000

High-frequency generators produce approx. the equivalent of a ____ increase in kVp, or slightly more than a doubling of mAs over single-phase power.

16%

A 14-bit depth can display ____ shades of gray

16,384

What object prohibits the flow of electrons?

Insulator

a cross-link formed between 2 places on the same DNA strand

Intra-strand cross-link

What is the relationship between frequency and wavelength with EM radiation?

Inverse - Higher frequencies are associated with shorter wavelengths and higher energies

The force of attraction between poles is governed by what law?

Inverse square law

What law governs the intensity of x-radiation, and states that the intensity of the x-ray beam is inversely proportional to the square of the distance between the source of the x-rays and the object?

Inverse square law

Removal of an electron form an atom is called?

Ionization

What is electromatgnetic radiation that is able to remove an electron from an atom?

Ionizing radiation

What do you understand of the term intensity?

Is it the energy of the x-ray beams or the number of x-rays?

What is attenuation?

Is the reduction in x-ray intensity that result from absorption and scattering.

What is half life of a radioisotope?

Is the time required for a quantity of raiocactivity to be reduced to one-half its original value.

What is characteristic radiation?

Is when electrons jump from the outer shell to the inter-shell

these have the same atomic mass number but different atomic number

Isobars

these have the same atomic number and same mass number

Isomers

these have the same number of neutrons

Isotones

A atom with the same number of protons but different number of neutrons is called what ?

Isotopes

these have the same number of protons

Isotopes

Explain the production of Bremstrahlung x-rays?

It gets close to the nucleus then slows down and moves into a new direction.

What is half value layer (HVL)?

It is the thickness of absorbing material necessary to reduce the x-ray intensity to half its original value.

What happens when a bar magnet is heated to a very high temperature?

It loses its magnetic properties

What is the function of the focusing cup?

It's a metal shroud that surrounds the filament.

What is the light transmittance formula

It/Io x 100 (It = amount of light transmitted, Io = amount of original light incident on the film)

he concluded that electrons were an integral part of all atoms

J.J. Thomson

he described the atom as looking something like a plum pudding, where the plums represented negative electric charges

J.J. Thomson

he investigated cathode rays (electrons) in the late 1890's

J.J. Thomson

the person that discovered electrons in 1897 and come up with the "plum-pudding" model of the atom

J.J. Thomson

he discovered the neutron

James Chadwick

In the late 19th century, he showed that visible light has both electric and magnetic properties

James Clerk Maxwell

he heavily researched color blindness

John Dalton

showed that the elements could be classified according to integral values of atomic mass; a unit of atomic weight was called a "dalton" for many years

John Dalton

the "Father of Modern Atomic Theory"

John Dalton

What are the Maximum Number or Electrons that can occupy each electron shell?

K = 2 L = 8 M = 18 N = 32 O = 50 P = 72 Q = 98

9. There are many characteristic radiations (K, L, M, and N). Which characteristic radiation is useful for imaging? Why?

K is the stronger shell for penetration.

innermost electron shell

K shell

the only characteristic x-rays of tungsten with sufficient energy to be of value in diagnostic radiology

K x-rays

x-rays that result from electron transitions into the K shell are called this:

K x-rays

name the orbital shells from innermost to the fourth outer shell

K, L, M, N, O . . .

What is its equation for kinetic energy?

KE = ½ mv2

What is energy of motion?

Kinetic energy

State the formula for the relationship between mass & velocity as it affects kinetic energy

Kinetic energy = 1/2 mass x (velocity)^2

What are the factors that affect x-ray quality?

Kvp more filter

states that the most pronounced radiation effects occur in cells having the least maturity and specialization, or differentiation; the greatest reproductive activity; and the longest mitotic phase

Law of Bergonie and Tribondeau

states that energy can be neither created or destroyed

Law of Conservation of Energy

states that matter can be neither created or destroyed

Law of Conservation of Matter

What law states that energy connot be created or destroyed and only changed in form?

Law of conservation of energy

What law states that matter connot be created or destroyed and only changed in form?

Law of conservation of matter

What law states that unlike charges attract, and like charges repel;electrostatc charges reside on the outer surface of a conductor and are concentrated at the area of greaest curvature: only negative charges move?

Laws of electrostatics

What law states like poles repel, and unlike poles attract?

Laws of magnetics

X-rays that leak through the protective covering is called what?

Leakage radiation

What are the 3 fundamental units of measurements?

Length (meters) Mass (kg) *Time (seconds)

a method of adjusting the voltage to the x-ray imaging system to a constant value, in response to changes in voltage supplied by the power company

Line compensation

What keeps incoming voltage to the Radiology Department adjusted to proper value?

Line voltage compensation

The larger the actual focal spot, the greater the heat capacity; the smaller the effective focal spot, the greater the raiographic image sharpness. What is this effect called?

Line-focus principel

average energy deposited per unit length of track

Linear Energy Transfer (LET)

What is the sensing agent in a TLD?

Lithium fluoride

Carbohydrates are most abundant in which tissues?

Liver tissue Muscle tissue

What is the optical density formula

Log10 Io/It (log base10 of Io over It)

List 3 examples of Derived Quantities:

Volume Density *Velocity

What is the chemical symbol for Tungsten?

W

What are the most important inorganic compounds?

Water Mineral salts

unit of power

Watt

What is the concept called that although x-ray photons exist as waves, the exhibit properties fo particles.

Wave-particle duality

principle that states that both wave and particle concepts must be retained, because wave-like properties are exhibited in some experiments and particle-like properties are exhibited in others

Wave-particle duality

What is the relationship between anode angle and effective focal spot size?

When the target angle is made smaller, the effective focal spot size also is made smaller.

What is a 15% rule?

When you increase. kVp 15% you double the mAs.

W represents

Workload

radiation output weighted time during the week that the unit is actually delivering radiation

Workload

Name 5 things designed to minimize radiation exposure to the patient and the operator.

X-ray beam filtration X-ray beam collimation Protective apparel and barriers Fluoroscopic cumulative timer *Protective tube housing

the only forms of electromagnetic radiation with sufficient energy to ionize

X-rays - gamma rays - ultraviolet light

List 4 Examples of electromagnetic radiation:

X-rays Gamma rays Visible light Radio waves

One of the substantive statements of Planck's Quantum Theory

X-rays are created with the speed of light (c), and they exist with velocity (c) or they do not exist at all.

What is off focus radiation?

X-rays produced in the anode but not at the focal spot.

symbol for atomic number

Z

electrons have a negative charge, and are surrounded by a kind of invisible force field called this

an electrostatic field

each block on the Periodic Table of the Elements represents this

an element

also referred to as saccharides; make up about 1% of cell content

carbohydrates

the basic constituent of all organic matter

carbon

Focal-spot blur is greater on the ___ side of the image

cathode

the negative side of the x-ray tube

cathode

which side of the beam is "hotter"

cathode

which way do electrons flow in the x-ray tube?

cathode to anode

Spatial resolution is dependent on having some ____ between separate objects

space

No more electrons can be boiled off of the filament because of this phenomenon

space charge

electron cloud around the filament

space charge

this makes it difficult for subsequent electrons to be emitted by the filament because of electrostatic repulsion

space charge effect

___ refers to the smallest object that can be detected in an image

spatial resolution

The accuracy of the anatomic structural lines recorded in the radiographic image is determined by its ____ and _____

spatial resolution, recorded detail

Diagnostic quality is achieved by maximizing the amount of _____ or _____ and minimizing the amount of _____

spatial resolution, recorded detail, distortion

The accuracy of the structural lines is achieved by maximizing the amount of ____ or ____ and minimizing the amount of _____

spatial resolution, recorded detail, distortion

additional quantities that are designed to support measurement in specialized areas of science and technology

special quantities

____ is calculated by determining the film curve which reaches its speed point (1.0 OD above base + fog) with the least amount of exposure

speed

Name the 2 types of anodes:

stationary rotating

The ________ is outside the glass envelope.

stator

The destruction of ____ cells in the intestinal lining causes death from GI syndrome.

stem

if there are more windings on the primary side versus the secondary side of a transformer, you have a ________ transformer

step down

Does a step-up transformer or a step-down transformer have more turns in the primary coil than in the secondary coil?

step-down transformer

necessary for the filament circuit to decrease voltage & increase amperage

step-down transformer

necessary for the high-voltage circuit to increase voltage

step-up transformer

type of transformer in which the secondary voltage is higher than the primary voltage because the number of secondary windings is greater than the number of primary windings

step-up transformer

A _____ effect increases in incidence but not severity as the dose increases.

stochastic

Artifacts specific to film-screen imaging are typically a result of film _____, ____, and _____

storage, handling, chemical processing

The area between the toe and the shoulder on a characteristic curve is called the

straight-line portion

Which portion of the characteristic curve represents the useful densities in the image

straight-line portion

proteins such as those found in muscle that provide the body with its shape and form and are a source of heat and energy

structural proteins

particles that are much smaller than the atom

subatomic particles

The absorption characteristics of the anatomic tissue radiographed is called

subject contrast

the property of some materials to exhibit no resistance below a critical temperature

superconductivity

What type of cell is the most radiosensitive?

Lymphocytes

"Garbage disposal", "Suicide bags", "Digestive bags"

Lysosomes

Magnification can also be calculated as

MF=SID/SOD

The 3 Systems of Measurement

MKS CGS *British

an accumulation of many atomic magnets with their dipoles aligned

Magnetic domain

3 Characteristics of ionizing radiation that vary among the different types of radiation and determine the extent to which different radiation modalities transfer energy to biologic tissue:

Mass Charge *Energy

3 base quantities that are the building blocks of all other quantities

Mass Length *Time

What has form or shape and occupies space?

Matter

a German physicist whose mathematical and physical theories synthesized our understanding of electromagnetic radiation into a uniform model

Max Planck

he received the Nobel Prize in 1918

Max Planck

What results in emission of alpha particles, beta particles, and usually gamma rays?

Radioactive decay

What are the 3 imaging windows of the electromagnetic spectrum and what unit of measure is applied to each?

Radiofrequency (Hz) Visible light (meters) *X-radiation (electron volts)

characteristic of materials that allow x-rays to penetrate with a minimum of attenuation; they are nearly invisible on radiographs

Radiolucency

What is the second leading cause of lung cancer in the U.S.?

Radon

What naturally occuring radiation source is responsible for dosing to lung?

Radon 222 gas

What process changes alternating current to direct current?

Rectification

the process of changing alternating current and voltage into direct current and voltage

Rectification

What does the G.mA control (filament circuit)?

Regulates the nimber of electrons available at the filament to produce x-rays

the unit used to express the quantity of radiation received by radiation workers & populations

Rem

5 Electrostatic Laws

Repulsion-Attraction Coulomb's Law Distribution Concentration *Movement

believed to be the way in which 95% of single-chromosome breaks mend

Restitution

List 4 consequences to the cell from structural changes in biologic tissue:

Restitution Deletion Broken-end rearrangement Broken-end rearrangement without visible damage to the chromatids

"Protein Factories"; they are attached to & are part of the rough ER

Ribosomes

the unit of measure of radiation in the air; applies only to x-rays & gamma rays & their interaction with air

Roentgen (R)

unit that applies only to x-rays and gamma rays and their interactions with air

Roentgen (R)

Who coined the terms "alpha particles", "beta particles" & "gamma rays"?

Rutherford

person noted for introduction of a nuclear model where the atom had a small dense positively charged center surrounded by negative charged cloud of electrons

Rutherford

A change in kVp affects both the ______ and the _____ of the x-ray emission spectrum.

amplitude, position

How much added filtration does the collimator provide? ...why?

an additional 1 mm Al equivalent that results from the silver surface of the mirror in the collimator

True or False: Atoms can be ionized by changing the number of positive charges.

False - positive charges do not move, but are confined to the nucleus

What year did Roentgen discover x-rays?

1895

What year did Roentgen win his first Nobel Prize in physics?

1901

The Snook transformer was developed in this year

1907

The Coolidge hot-cathode x-ray tube was introduced this year

1913

Unprotected head, neck & lenses of the eye receive how much more exposure than the protected body trunk?

10 to 20 times

What is the RPM of high speed anode?

10,000 rpm

In abdominal imaging, the entrance skin dose is approx _______times the exit dose in radiography or fluoroscopy.

100

the time it takes for the radioactivity to fall by half

"half-life"

For single-phase, kW =

(0.7) [mA x kVp / 1000]

The maximum allowable radiation leakage from the tube housing is:

100 mR/hr at a distance of 1 meter from the source

What is the weekly Maximum Permissible Dose for a controlled area?

100 mrem

energy range for pair production

1.02 MeV

Control booth glass windows typically contain ____ mm Pb equivalent.

1.5

What is the Background Equivalent Radiation Time for a patient receiving an Upper GI series?

1.5 years

How many mill roentgens is one roentgen?

1/1000

1 AMU is equal to

1/2 the mass of a carbon-12 atom

Exposure time must be below __ of a second for abdominal x-ray to prevent motion blurring by peristalsis

1/20

In the Bremsstrahlung x-ray emission spectrum, the highest number of x-rays have approx. ____ the maximum energy.

1/3

Most doors to x-ray imaging rooms contain ____ inch of Pb and must be closed when radiographic exposures or fluoroscopy is taking place.

1/32

Secondary protective barriers consist of ____inch Pb.

1/32

Exposure time must be below __ of a second for chest x-ray or the heartbeat will cause blurring

1/60

Gonadal responses to radiation have been observed at doses as low as _____ rads.

10

energy range for photodisintegration

10 MeV

Current federal standards limit entrance skin exposure rates of general-purpose intensified fluoroscopic units to a maximum of _____ per minute.

10 R

What is the Background Equivalent Radiation Time for a patient receiving a chest radiograph?

10 days

When using three-phase operation, how much reduction in kVp would be required to produce the same image receptor exposure when operated at the same mAs as single phase?

10 kVp

the x-ray energy ranges

10 keV to 50 MeV

What is the lowest reading on a film badge?

10 mRem = .01 rem = .1mSv

Name 3 things that may be given out when an unstable nucleus decays

Alpha particle Beta particle *Gamma ray

List 4 examples of high LET radiation:

Alpha particles Ions of heavy nuclei Low energy neutrons Charged particles released from interactions between neutrons and atoms

Electrical circuit in which the current of electrons oscillates back and forth is called what?

Alternating current (AC)

What are OSL filters made of?

Aluminum Copper *Tin

What type of metal filters are in a film badge?

Aluminum or Copper

What is the sensing agent in OSL dosimeters?

Aluminum oxide

What is the tube housing made of?

Aluminum with lead lining

Watts =

Amps x Volts

The positive side of the x-ray tube is called?

Anode

What is it called when partial absorption of the energy of an x-ray beam as it traverses an object?

Attenuation

a device that measures the quantity of radiation that reaches the image receptor and automatically terminates the exposure when the image receptor has received the required radiation intensity

Automatic Exposure Control (AEC)

What is used to provide consistency of radiographic quality?

Automatic exposure contral (AEC)

Transformer that contains an iron core and a single winding of wire is called what?

Autotransformer

a type of transformer having a single winding

Autotransformer

an iron core transformer with only one winding

Autotransformer

Antibodies are molecules produced by specialized cells in bone marrow called __________.

B lymphocytes

What produces antibodies?

B lymphocytes

A phosphor that glows when excited with x-rays. The phosphor with which Roentgen was experimenting when he discovered x-rays.

Barium Platinocyanide

the 3 fundamental units of measurements

Base Quantity

Use factor is also called

Beam direction factor

Where is the mA meter located?

Between the rectifier and x-ray tube

the energy that causes electrons to move in a conductor; measured in volts (V)

Electric potential

Electric current (A) through a potential (V)

Electric power

What is the path along whtich electrons flow called and may be wired as series circuits or parallel circuits?

Electrical circuits

What is movement of electrons along a conductor or pathway (electrical circuit), and measures in ampres?

Electrical current

What is energy resulting from movement of electrons?

Electrical energy

What is the divice that converts mechanical energy to electrical energy called?

Electrical generator

What is the device called that converts electrical energy to mechanical energy?

Electrical motor

What is measured in ohms?

Electrical resistance

What is movement of electrons betwee objects called?

Electrification

What is it called when electrical charges are in motion?

Electrodynamics

the study of electric charges in motion

Electrodynamics

Current-carrying coil wrapped around a ferromagnetic core

Electromagnet

Solenoid with an iron core that concentrates the magnetic field is called wihat?

Electromagnet

What ies energy that is emitted and transferred through matter?

Electromagnetic energy

What is it called when a process of causing an electrical current to flow in a conductor when it is placed within the magnetic field of another conductor?

Electromagnetic induction

the wide range of electromagnetic radiation described by its frequency, wavelength, or energy

Electromagnetic spectrum

What is it called when movement of electrons in a conductor produces a magnetic field around the conductor (a coiled conductor, through which an electrical current is flowing, has overlapping magnetic fields)?

Electromagnetism

What is measured in volts, and is the force with which electrons move in an electrical circuit?

Electromotive force (EMF)

What is it called where electrons are when they go around the nucleus of an atom?

Electron Cloud

What is space charge?

Electron cloud near the filament

What contains orbital electrons (negative charges), is represented by the letters K, L, M, N, O, P, and Q, is in a stable atom, and the nimber of electrons and protons is equal?

Electron shells

What is the force called that holds electrons in orbit around the nucleus?

Electron-binding energy

What type of timer is contained in most radiographic equipment?

Electronic timer

Stationary electrical charges (static electricy) called?

Electrostatics

stationary electric charges

Electrostatics

What does the tube housing do?

Encases the x-ray tube

What is the amount of matter in an object; generally considered the same as weight?

Energy

What is meant by x-ray quality? (Energy or quantity)

Energy... The ability of x-rays to penetrate deeper into tissue.

when natural sources of radiation become increased because of accidental or deliberate human actions such as mining, they are termed this

Enhanced Natural Sources

science that deals with the incidence, distribution, and control of disease in a population

Epidemiology

type of highly radiosensitive cells found in the lining of the intestines, the mucous lining of the respiratory tract, pulonary alveoli and lining of blood & lymphatic vessels

Epithelial tissue

a radiation quantity used for radiation protection purposes when a person receives exposure from various types of ionizing radiation; this quantity attempts to numerically specify differences in biologic harm that are produced by different types of radiation

Equivalent Dose (EqD)

he called the center of the atom the nucleus

Ernest Rutherford

he coined the terms alpha particles, beta particles, and gamma rays

Ernest Rutherford

he disproved Thomson's atomic model in 1911

Ernest Rutherford

he introduced the nuclear model

Ernest Rutherford

List the 4 Special Quantities of Radiation Measurement:

Exposure Dose Effective dose Radioactivity

This agency regulates the design and manufacture of x-ray equipment

FDA

regulates the design and manufacture of products used in the radiation industry

FDA (U.S. Food and Drug Administration)

What is a modern generator that take s advantage of exremely short time capabilites and tube hear-loading potential?

Falling load gen4erator

X-ray quantity is proportional to the kVp. True or false?

False

True or False - Electromagnetic radiation travels at the speed of light (186,000 miles per hour).

False - its 186,000 miles per second

What is the number of wavelenghts passing a given point per unit time and is measured in hertz (Hz) called?

Frequency

X-ray beam quality can be identified most appropriately by its

Half value layer (HVL)

a condition in which the voltage is not allowed to swing negatively during the negative half of its cycle

Half-Wave Rectification

the German physicist that developed the first reliable detector for ionizing radiation

Hans Geiger

a form of ionizing electromagnetic radiation emitted from the nucleus of a radioactive atom

Gamma ray

What are electromagnetic rays called that are produced in the nucleus of radiactive atoms?

Gamma rays

Units of magnetic intensity

Gauss & Tesla

What does GSD stand for?

Genetically significant dose

the average gonadal dose given to members of the population who are of childbearing age

Genetically significant dose (GSD)

"Carbohydrate-producing and-packaging factory"

Golgi Apparatus

SI unit of patient dose

Gray

the SI equivalent for rad

Gray (Gy)

Cytosine always bonds with ________.

Guanine

What are 2 other names for a characteristic curve

H&D curve, sensitometric curve

What is the best method to specify x-ray quality?

HVL is most appropriate.

What is the function of oil inside the protective housing?

Helps the cooling of the tube.

he shared the 1903 Noble Prize for Physics with Marie and Pierre Curie

Henri Becquerel

High frecuency generators poduce what?

High-frequency electricity (thousands of hertz)

type of generator that produces a nearly constant potential voltage waveform, improving image quality at lower patient radiation dose

High-frequency generator

the international, collaborative research program whose goal was the complete mapping and understanding of all the genes of human beings

Human Genome Project

Why is electrification easier in dry Phoenix than in humid Houston?

Humidity allows excess electrons to attach to water molecules in the air.

Who first described the characteristic curve relationship

Hurter and Driffield

makes recommendations on occupational and public dose limits

ICRP (International Commission on Radiological Protection)

List 7 Cellular Effects of Irradiation:

Instant death Reproductive death Programmed cell death (Apoptosis) Mitotic death Mitotic delay Interference with function *Chromosome breakage

How can you increase the kinetic energy of electrons travelling from filament to anode?

Increase KVP

The property of matter that acts to resist change in its state of motion as described in Newton's first law

Inertia

Which interaction produces characteristic radiation? (Inner shell or outer shell?)

Inner shell

what part of the image intensifier changes x-ray photons into light photons?

Input phosphor

the watchdog of the nuclear energy industry; it controls the manufacture and use of radioactive substances

NRC (Nuclear Regulatory Commission)

What type of charge is a Electron?

Negative

What is a Cathode assembly?

Negative elecrode in the x-ray tube

What type of charge is a neutron?

Neutral

SI unit for force

Newton

the force on an object is equal to its mass multiplied by its acceleration

Newton's Second Law of Motion

he developed the concept of the atom as a mini solar system

Niels Bohr

he improved Rutherford's nuclear model in 1913

Niels Bohr

his nuclear model was a miniature solar system in which the electrons revolved about the nucleus in prescribed orbits or energy levels

Niels Bohr

What composes the steps or rungs of the DNA ladder?

Nitrogenous bases

What indicates the kilovoltage that will be flowing through the tube oned the exposure is made?

Prereading voltmeter

The shell number of an atom is called

Principle Quantum Number

What are the 3 Electron-Target Interactions?

Production of heat Characteristic *Bremsstrahlung

List the fundamental particles of an atom:

Protons Neutrons *Electrons

Name 5 Personal skills required by the ARRT:

Provide instructions to the patient Position Patient Prepare the patient Confirm patient identity *Observe and monitor vital signs

a single unit of electromagnetic radiation

Quantum

describes the relative capabilities of radiation with differing LETs to produce a particular biologic reaction

RBE (Relative Biologic Effectiveness)

covers a considerable portion of the electromagnetic spectrum and has relatively low energy and relatively long wavelength

RF (radio frequency)

What is another name for single-strand DNA?

RNA

responsible for developing a radiation safety program for the health care facility; he or she maintains personnel radiation-monitoring records and provides counseling in radiation safety

RSO (Radiation Safety Officer)

the unit most often used when describing the quantity of radiation received by a patient

Rad

time required to reduce radioactivity to half its original value

Radioactive Half-life

Which has the greater magnitude? Protons or electrons?

The electric charges associated with an electron and a proton have the same magnitude but opposite signs.

How is the energy of a photon and its frequency related?

The energy of a photon is directly proportional to its frequency.

How is the energy of a photon related to its frequency?

The energy of a photon is directly proportional to its frequency.

A step-up transformer is used in the x-ray circuit to increase what?

Voltage to the kilovoltage level for x-ray production

What is the role of magnetism in the study of x-ray imaging?

The high voltage generators in x-ray imaging systems are magnetic devices.

What is x-ray quantity mean?

The intensity of the x-ray beam of an x-ray imaging system

What is x-ray quantity means?

The intensity of the x-ray beam of an x-ray imaging system.

At what distance from the source can the inverse square law be applied?

The inverse square law can be applied to distances greater than seven times the longest dimension of the source.

What is heat energy resulting form movement of atoms of molecules?

Thermal energy

What changes electrical voltage and current into higher or lower values?

Transformer

True or False - Thicker part of the body must be place under the cathode side of the x-ray tube.

True

True or False - Travel at the speed of light is constant regardless of wavelength or frequency.

True

True or False - Wavelength and frequency of electromagnetic radiation are inversely proportional?

True

True or False: A cell placed in water without salts would die.

True

True or False: An ion pair is formed when an electron is removed from an atom by ionizing radiation.

True

True or false - X-rays and gamma rays differ only in their origin.

True

List 5 Factors That Affect the Size and Relative Position of X-ray Emission Spectra:

Tube current (mA & mAs) Tube voltage (kVp) Added filtration Target material *Voltage waveform

What contains oil in which the x-ray tube is immersed to assist with cooling and additional electrical insulation?

Tube housing

What supports and protects the tube, restricts leakage radiation during exposure, and provides electrical insulation?

Tube housing

Relationship between filament current and tube current depends on what?

Tube voltage

The filament of an x-ray tube is made of _________ metal.

Tungsten

Area frequented by general public

Uncontrolled area

What is roentgen (R)?

Unit of exposure

What is roentgen?

Unit of exposure, which is the measure of the ionization produced in air by x or gamma radiation.

List the 4 laws of electrostatics:

Unlike charges attract, like charges repel Coulomb's Law of Electrostatic Force Electrostatic force follows the inverse square law Electric charges are uniformly distributed except at regions of high curvature where they concentrate

Proportional amount of time during which an x-ray beam is energized or directed toward a particular barrier.

Use factor

U represents

Use factor

Ohm's Law

V = I R

The Ohm's Law Formula

V = IR

Ohm's law

V=IR

What is the wave equation?

Velocity = frequency x wavelength

The 9 categories of Mechanics

Velocity Acceleration Newton's Laws of Motion Weight Momentum Work Power Energy *Heat

a narrow region in the middle of the electromagnetic spectrum extending from approx. 400 nm (blue) to 700 nm (red)

Visible light

What is the distance between the cathode and the anode?

about 1 cm

What 2 distinct processes occur during beam attenuation

absorption, scattering

QC program includes:

acceptance testing, performance monitoring, and maintenance

how do you calculate atomic mass

add protons and neutrons

another word for oxygenated

aerobic

describe the way in which elements in a group on the periodic table react chemically

all elements in a group react chemically in a similar fashion & have similar physical properties

fast-moving particles capable of ionization

alpha & beta particles

composed of 2 protons and 2 neutrons and carries an electric charge of plus 2

alpha particle

most damaging form of ionizing radiation

alpha particle

the nucleus of the helium atom - two neutrons and two protons

alpha particle

this type of particle is easy to stop

alpha particle

type of ionizing radiation that travels the least distance

alpha particle

this type of radioactivity has a low penetrating power, a short range in air and can be stopped by a sheet of paper

alpha particles

type of radioactivity that has 2 protons & 2 neutrons

alpha particles

unit of electric current

amp

What is the unit of measure of the primary current?

amperes (A)

the filament current, which controls the filament temperature, is measured in this unit of measure:

amperes (A)

What is wave hight called?

amplitude

one-half the range from crest to valley over which the sine wave varies

amplitude

what changes about the voltage waveform from primary to secondary side of the x-ray circuit

amplitude

the substance that coated the plate that fluoresced when Roentgen discovered x-rays

barium platinocyanide

Optical density inherent in the base of the film

base density

Give examples of good sources of direct current:

batteries solar cells fuel cells some types of generators

what would provide a DC?

battery

this increases the number of high energy x-rays in the beam by removing the lower-energy nonpenetrating x-rays.

beam hardening

HVL is a measurement of

beam quality

as the peak of the x-ray emission spectrum moves to the left, what is affected? How?

beam quality decreases

Why is Characteristic radiation called "characteristic"?

because it is characteristic of the target element

this is why alpha particles are so dangerous

because they ionize so strongly; if ingested in your body, they can ionize atoms in the cells of your body

What is the radon limit established by the EPA?

below 4 picocuries per liter (pCi/L)

SI unit of radioactivity

bequerel

electromagnetic wave equation

c=frequency x wavelength

E=mc(squared) can be used in radiology for what purpose

calculating mass equivalence of x-ray photons

List several ways digital imaging has overcome the limitations of film imaging

can be quickly electronically processed, displayed, stored, duplicated, and transmitted, has greater dynamic range and contrast resolution

types of induction

self, mutual

a material that under some conditions behaves as an insulator and in other conditions behaves as a conductor

semiconductor

this class of materials lie between the range of insulators and conductors in their ability to conduct electricity and serve a the basis for today's solid-state microchip marvels

semiconductors

The ability of an image receptor to respond to a low x-ray exposure is a measure of its

sensitivity

What 2 items are needed to construct a characteristic curve

sensitometer, densitometer

The study of the relationship between the intensity of exposure of the film and the blackness after processing is called

sensitometry

Which type of circuit do the following laws apply: total R=R1+R2+R3; total I= I1=I2=I3; total V=V1+V2+V3

series

A radiograph is similar to a ____ because both light and x-ray photons travel in straight lines

shadowgraph

Unequal magnification of different portions of the same object is called

shape distortion

What are several terms used for a small number of widely varying tonal values

short scale, high contrast, zebra

High contrast is also called

short-scale contrast

The top portion of a characteristic curve which shows only small change in OD is called

shoulder

What is the SI unit of measure for Equivalent Dose (EqD)?

sievert (Sv)

variations of amplitude over time

sine waves

to figure HU for a _________phase generator, multiply kVp x mA x s

single

this term means "simple motion; a sine wave"

sinusoidal

An increase in the image size of an object compared with its true or actual size

size distortion (or magnification)

Which focal spot produce high special resolution, Small or large?

small

The greater the number of pixels in an image matrix, the ____ their size

smaller

the effective focal spot is ____ than the actual focal spot

smaller

List 3 advantages of high-frequency generators over 60 Hz high-voltage generators

smaller less costly *more efficient

List 7 uses of Radioactivity

smoke detectors thickness control sterilizing radioactive dating radioactive tracers checking welds *cancer treatment

Why does the glass envelope contain a vacuum?

so that the electrons form the filament do not collide with atoms of gas.

List 2 examples of electrolytes:

sodium (Na) potassium (K)

magnet created by a coil of wire with a current passing through it

solenoid

What has replaced the original diode rectifiers that were vacuum tubes called valve tubes?

solid-state rectifiers made of silicon


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