Radiology Midterm 2

Which of the following is used as a collimator?

Lead plate

The unsharpness or blurred edges seen on a radiograph image is termed:

Penumbra

fixer cutoff

Straight black border on film= low levels of fixer

The safety of a darkroom safelight depends on the:

Distance of the safelight from the workbench, time the films are exposed to the safelight, speed of the film

MAximum Permissible dose for nonoccupational exposed person:

.5 Rem/yr (.005 Sv/yr)

A variation in the true size and shape of the object being radiographed is termed:

Distortion

Machines operating at 70 kVp or lower require________mm aluminum

1.5

In manual processing, the fixing time for films is usually:

10 mintues

What is the average dose of background radiation received by an individual in the US?

150-300 mrads(.0015-.003Gy)

Machines operating at 70kVp or higher require________ mm aluminum

2.5

For dental radiography, the recommended collimation of the radiation beam of the BID at the patient's skin:

2.75 in.

Which of the following is the recommended size of the beam at the patient's face?

2.75 inches

In hand processing, films should be washed in running water for at least:

20 minutes

A single intraoral radiograph (D-speed film, 70 kVP, long PID) results in a mean surface exposure of:

250mR

A free radical:

Is an uncharged molecule, has an unpaired electron in the outer shell, is highly reactive and unstable, combines with molecules to form toxins

The safelight must be placed a minimum of what distance from the film and working area?

4 feet

The optimum time and temperature for hand development of film is:

4.5 to 5 min. at 68-70 degrees F

At 68 degrees F, what is the optimum development time?

5 minutes

Maximum Permissible dose for occupational exposed person:

5.0 Rem/yr(.05 Sv/Yr)

What is the dose at which leukemia induction is most likely to occur?

5000 mrads (0.05 Gy)

The optimal temperature for the developer solution is:

68 degrees F

Which of the following describes the relationship of the central ray to the film paralleling technique?

90 degrees to the film and long axis of the tooth

What is the angle that the dental radiographer should stand to the primary beam:

90-135 degrees and 6ft away

The type of contrast preferred in dental radiography is:

A compromise b/w short-scale contrast and long-scale contrast

Occlusal Film

A film used to examine a large area of the maxilla or mandible in one film

Bite-wing Film

A film used to examine the crowns of the upper and lower teeth on a single film

Periapical Film

A film used to examine the entire tooth and supporting bone

Which of the following describes the use of a filter in a dental x-ray tubehead?

A filter removes the low energy x-rays

Which of the following is not a component of inherent filtration?

A leaded cone

Which of the following appears most radiolucent on a dental radiograph?

Air space

Which of the following is correct concerning film placement?

Anterior films are placed vertically and posterior films are placed horizontally.

Fogged Film

Appears gray and little detail=improper film storage/outdated films

Static electricity

Black branching lines= opening film packet too quickly

Fingernail artifact

Black, crescent-shaped marks=rough handling

The hydroquione in the developer brings out the _______ tones, whereas the Elon in the developer brings out the _________tones on a dental radiograph.

Black;gray

An example of a radiopaque structure seen on dental x-rays:

Bone, enamel, and dentin

Which of the following can be used to clean the processing tank?

Both commercial tank cleaners and hydrochloric acid(1.5 ounce) with 128 ounces of water solution.

Which of the following controls total magnification (included penumbra) of the radiographed object?

Cathode size, object-film distance, focal spot-film distance, focal spot size

Unopened boxes of radiographic film should bot be stored in the darkroom b/c:

Chemical fumes from processing solutions may fog the film

Which of the following devices restricts the size and shape of the x-ray beam?

Collimator

A replenisher is added to the processing solution to:

Compensate for the loss of solution strength, ensure uniform results b/w solution charges, compensate for the loss of volume of solution, compensate for oxidation.

The difference in the degrees of blackness b/w adjacent areas on a dental radiograph is termed:

Contrast

An organ that if damaged diminishes the quality of an individual's life is termed:

Critical organ

Developer spots

Dark spots of film

Beam perpendicular to object and film=

Decrease distortion

Object and film are parallel=

Decrease distortion

Decrease Object-film distance=

Decrease magnification

Increase Target-film distance=

Decrease magnification

Increase crystal size=

Decrease sharpness

Increase movement=

Decrease sharpness

Replenisher pump

Delivers developer and fixer solution to compartments

The overall blackness or darkness of a dental radiograph is termed:

Density

The thermometer for manual processing should be placed in the:

Developer solution

The first step in film processing is:

Development

Which of the following is incorrect concerning the exposure sequence for pericapical films?

Either posterior or anterior films may be exposed first.

Processor housing

Encases component parts of automatic processor

Light leak

Exposed area is black= exposed to light

he latent period in raditation biology is the time between:

Exposure to x-radiation and clinical symptoms

Overdeveloped Film

Film appears too dark b.c of excess dev. Time & high dev. Temp.

Underdeveloped film

Film appears too light b/c of low dev. Time, depleted dev. Solution

Which of the following is true of film badges?

Film badges should be worn at the waist level when exposing x-ray films

Any leaks of white light into the darkroom will cause:

Film fog

The amount of radition exposure an individual receives varies depending on which of the following factors?

Film speed, Collimation, technique. Exposure factors

Which of the following will not produce film fog?

Films stored in a refrigerator in the lab

The film emulsion is hardened during:

Fixation

Radiation injuries that are not seen in a person irradiated but that occur in future generations are termed:

Genetic effects

Which of the following is a unit of radiation absorbed dose expressed in joules per kilogram of irradiated tissue?

Gray (Gy)

The radiation weighting factor is used in the determination of which of the flowing radiation units?

Gy

The unit of x-radiation measurements that deals with the absorbed energy per kilogram of tissue is the:

Gy

Drying chamber

Heated air is used to dry wet films

When viewed on a light source, a dental radiograph that demonstrates very dark areas and very light areas is said to have:

High contrast

Which of the following reduced the radiation dose to the patient?

High-speed film, Collimator, digital imaging, gonadal shields

The Size of a darkroom is determined by all the following except:

Humidity level of the room

Which of the following is correct concerning the lack of parallelism between the film and the long axis of the tooth?

If less than 20 degress, the film is generally acceptable.

BID (cone) cutting (partial image) on a radiograph is caused by:

Improper coverage of the film with the beam of radiation.

What is the cause of yellow or brown stains appearing on films some time after processing?

Incomplete fixing and washing

Increase Object-film distance=

Increase magnification

Decrease crystal size=

Increase sharpness

Decrease focal spot size=

Increase sharpness

Decrease movement=

Increase sharpness

dental patient had thick soft tissues and dense bones. To compensate for this increase in subject thickness and provide a film of diagnostic density, the dental radiographer:

Increase the mA, kVp, and exposure time

Increasing the mA will cause:

Increases the density and makes the film darker

increasing the exposure time will cause:

Increases the density and makes the film darker

increasing the kVP will cause:

Increases the density and makes the film darker

The GBX-2 safelight filter by Kodak is recommended for:

Intra and extraoral films

The intensity of x-radiation at any given distance from the source of radiation varies:

Inversely with the square of the distance

Which of the following effects can be associated with low-dose, whole body radiation?

Leukemia

Which of the following will produce film fog?

Light leaks in the dark room, films stored for a ling time in an unsafe place, unprotected films in the x-ray room or x-ray equipped operatory.

Fixer spots

Light or white spots on film

Which of the following relationships describes the response of tissues to radiation:

Linear; nonthreshold

Which of the following statements is correct?

Long-term effects are seen within small amounts of radiation absorbed in a long period

When viewed on a light source, a dental radiograph that demonstrates many shades of gray is said to have:

Low contrast

The geometric characteristics that refers to a radiograph image that appears larger than its actual size is termed:

Magnification

Which of the following is considered radioresistant?

Mature bone cells

Which of the following terms describes the dose of radiation that the body can endure with little or no chance of injury?

Maximum permissible Dose

What is the greatest contributor to artificial radiation exposure?

Medical radiation

The sensitivity of tissues to radiation is determined by:

Mitotic Activity, cell differentiation, cell metabolism

Film recovery slot

Opening where processed films emerge

The one exposure factor that has a direct influence on the contrast of a dental radiograph:

Operating kVp

A breakdown of chemicals in the processing solution that results from exposure to air is termed:

Oxidation

Differences between manual and automatic processing include which of the following?

Processing solution chemistry, solution temperature, solution concentration, time to completion of processing

When an 8in. target-film distance is changed to a 16in. target-film distance (kVp and mA kept constant), the exposure time should be:

Quadrupled

The unit for measuring the absorption of x-rays is termed:

Rad

The portion of a processed radiographed that appears dark or black is termed:

Radiolucent

the portion of a processed radiograph that appears light or white is termed:

Radiopaque

Which of the following position-indicating devices is most effective in reducing patient exposure?

Rectangular PID

Which of the following describes the function of filtration?

Reduced low energy waves

The quality factor (QF) is used to determine which of the following radiation units?

Rem

The superconcentrated solution that is added to the processing solution to compensate for the effects of oxidation is termed:

Replenisher

Which of the following is the most radiosensitive?

Reproductive organs

Which of the following definitions is incorrect? Which of the following definitions is incorrect?

Right angle:formed by two parallel lines→ should be perpendicular

n film processing, the rinsing step is necessary because:

Rinsing removes the developer from the film and stops the development process

The capability of the x-ray film to reproduce distinct outlines of an object is termed:

Sharpness

Which of the following is not critical factor in the radiation response of cells?

Size of cells

Which of the following is most susceptible to ionizing radition?

Small lymphocyte

Air bubbles

Small white spots=need to stir film racks after placing in processing solution

Replenisher solutions

Solutions used to maintain proper concentration and levels of developer and fixer

Which of the following is used only for x-rays?

The Roentgen

Which of the following traditional units does not have an SI equivalent?

The Roentgen

The traditional unit for measuring x-ray exposure in air is termed:

The Roetgen

Which of the following describes the relationship of the film and the long axis of the tooth in the paralleling technique?

The film and tooth are parallel to each other.

Which of the following describes the distance between the film and the tooth in the paralleling technique?

The film is placed away from the tooth and toward the middle of the oral cavity.

Occlude

To close or bite

All the following factors affect the life of the processing solutions except:

Type of safelight filter used

The long BID (Cone) is recommended when using the paralleling technique bc we can:

Use a longer focal spot-film distance to compensate for a greater object-film distance to reduce magnification and distortion.

What is the main cause of foreshortening in the bisecting-angle technique?

Vertical angulation of the BID is insufficient

Overlap film

When two films come into contact-in dev =white areas/ in fixer=black areas

How often should the processing tank be cleaned?

Whenever solutions are changed

Dentulous

With teeth

Enentulous

Without teeth

Which of the following statements is incorrect?

X-radiation is not harmful to living tissues.

Indirect radiation injury occurs when:

X-ray photons are absorbed and form toxins

Direct radiation injury occurs when:

X-ray photons hit critical targets within a cell

Formula for Maximum accumulate dose:

[N-18] x 5.0 rems/yr

Which of the following conversions is correct?

all of they above.

X-ray filters are usually made of:

aluminum

The technique that shows the upper and lower crowns and associated alveolar bone on the same radiograph is called the:

bitewing technique

Scratches

black branching lines= opening film packet too quickly

Which of the following tissues is most susceptible to radiation?

blood-forming tissue

In hand processing, if you place the film in the fixer first, this results in:

clear film

Intensifying screens are used with extra oral and panoramic films to:

decrease the radiation to the patient

The size of the focal spot in the x-ray tube influences radiographic:

definition

The optimal density of an intramural film indicates the:

degree of darkness in an image

To test for chemically fogged or age-fogged film:

develop the film without exposing it

List three types of intaoral radiographic examinations:

eriapical, Bite-wing, and Occlusal

Relative to radiation biology, the latent period is that period between:

exposure to radiation and the appearance of clinical symptoms

Which of the following is the most effective method of reducing patient exposure to radiation?

fast films

Which of the following effects is not considered to be dependent on dose rate?

genetic effects

Yellow-brown stains

hausted developer or fixer, insuff. Rinsing or fixation time

Which of the following are advantages of the paralleling technique?

increased accuracy, simplicity of use, and ease of duplication

The primary advantage of the paralleling technique over the bisecting-angle technique is:

increased anatomic accuracy of the image

fog affects the contrast of an intramural film b/c it:

increases film density

The paralleling technique is recommended over the bisecting-angle technique bc:

it gives less-distorted picture of root length

Subject contrast is primarily a function of:

kVp

Optimal density is a function of :

kVp, mA, exposure time

Collimators are usually made of:

lead

A pregnant patient:

may be irradiated for dental radiographs by taking the proper precautions.

Roller film transporter

moves the film through the automatic processor

which of the following films can be used intraorally and extra orally?

occlusal film

Film/feed slot

opening to insert films

Which of the following factors contributes to radiation injury?

otal dose, dose rate, cell sensitivity, & age

Regardless of the target-film distance, incorrect horizontal angulation will cause:

overlapping of teeth in the x-ray image

In the bisecting-angle technique, the central ray of the beam is directed:

perpendicular to a line bisecting the angle formed by the object and the film packet.

Which is the hardening agent in film processing?

potassium alum

Which of the following is the most effective in reducing patient radiation dose?

proper collimation

Developer cutoff

straight white border on film= low levels of developer

True or False

the long BID is used with the paralleling or the bisecting-angle technique

Which of the following is a correct statement about intensifying screens?

thicker phosphor layers result in faster screens.

Why is the long BID considered a necessary adjunct to the paralleling technique?

to avoid magnification of the image

The stepwedge is used for all of the following except:

to increase the penetrating quality of the x-ray beam

The advantages of the paralleling technique outweigh the disadvantages:

true

A film is stripped from its packet and exposed to light. After processing it will:

turn black