RT 120 Quiz/test Q/A
The phosphor used in a CR imaging plate is: Amphorus Selenium Cesium Iodide Phenidone Barium fluorohalide crystals doped with europium
Barium fluorohalide crystals doped with europium
Four substances account for most the beam attenuation in the human body. Which has them in the correct order from the greatest beam attenuation to the least attenuation. -Muscle, Bone, Air, Fat -Bone, Muscle, Fat, Air -Bone, Air, Fat, Muscle -Fat, Bone, Air, Muscle
Bone, Muscle, Fat, Air
When making any exposure within the diagnostic range, most of your beam will be composed of ______ radiation. Brehmsstrhlung Characteristic Photoelectric Comptons
Brehmsstruhlung
The type of radiation that is produced when a projectile electron passes near the nucleus of a target atom and sheds it's kinetic energy in the form of a photon is known as: Characteristic Crookes Thompson's Brehmsstrulung
Brehmsstrulung
The type of x-ray interaction that happens when a projectile electron is slowed or stopped by the nucleus of an atom is: Characteristic Photoelectric Bremsstruhlung Comptons
Bremsstruhlung
The type of radiographic digital receptor that uses a phosphor coated plate that retains a latent image is: DR CR
CR
The Moire effect is demonstrated on -CR only -DR only -Both -No such thing
CR only
Quantum Mottle is: A double exposed image Off center distortion Caused by not using a grid Caused by using an insufficient technique when x-raying a body part
Caused by using an insufficient technique when x-raying a body part
The type of radiation that occurs when a projectile electron interacts with a K-shell electron is know as: Brehmsstruhlung Characteristic
Characteristic
The type of x-ray interaction that happens when a projectile electron collides with an inner K-shell electron, dislodges it from its orbit, and a photon is produced when an outer shell electron falls into the void, is called: Characteristic Bremsstruhlung Photoelectric Comptons
Characteristic
Which of the following could be defined as the production of an x-ray photon by a collision between the incident electron and a K-shell electron of the tungsten atom? -Photoelectric Interaction -Bremsstrahlung Interaction -Characteristic Interaction -Pair Production Interaction
Characteristic Interaction
The type of scatter radiation that is a risk to both the patient and anyone else in proximity to the patient is: -Characteristic -Compton's -Photoelectric -Coherent
Compton's
The type of scatter radiation that is produced when an incident photon interacts with an outer shell electron, sheds enough energy to remove that electron from its orbit and then continues on in a different direction minus the energy it lost during the interaction is called: Photoelectric Thompson's Compton's None of the above
Compton's
The type of scatter radiation that is produced when an incident photon interacts with an outer shell electron, sheds enough energy to remove that electron from its orbit and then continues on in a different direction minus the energy it lost during the interaction is called: Photoelectric Thompson's Compton's None of the above.
Compton's
Which interaction causes unwanted exposure (fog) to the image receptor? Photoelectric Effect Compton's Scatter
Compton's Scatter
The type of scatter radiation that can create biological changes and is a safety hazard for the technologist is: Compton's scattering Photoelectric effect Thompson's scattering Pair production
Compton's scattering
The type of scatter radiation that can create biological changes and is a safety hazard for the technologist is: Compton's scattering Photoelectric effect Thompson's scattering Pair production
Compton's scattering
The difference in density between two adjacent tissues is known as: -Contrast -Brightness -Attenuation -Absorption
Contrast
The anode heel effect will: Create more intensity at the anode end of the beam. Create more intensity at the cathode end of the beam. Create more intensity in the center of the beam. Decrease the intensity at the cathode end of the beam.
Create more intensity at the cathode end of the beam.
Increasing the kVp results in _____. A. X-rays with higher energy. B. X-rays with lower average energy. C. More x-rays produced. D. Both A and C. E. Both B and C.
D. both A and C
What is the communication standard for information sharing between PACS and imaging modalities? DQE DICOM SMPTE HL7
DICOM
The type of digital imaging system that is the fastest and most expensive is: DR CR
DR
Air in the chest and abdominal cavity will create a ____ area on the image -Dark -Air will not show up in an x-ray. -White or light
Dark
If you decrease the kVp settings at the control panel, you also: Decrease the penetrability of the beam and reduce the production of scatter radiation. Increase the penetrability of the beam but reduce the production of scatter radiation. Increase the penetrability of the beam and increase the production of scatter radiation. Decrease the penetrability of the beam while increasing the production of scatter radiation.
Decrease the penetrability of the beam and reduce the production of scatter radiation.
If you decrease the kVp settings at the control panel, you also: -Decrease the penetrability of the beam and reduce the production of scatter radiation. -Increase the penetrability of the beam but reduce the production of scatter radiation. -Increase the penetrability of the beam and increase the production of scatter radiation. -Decrease the penetrability of the beam while increasing the production of scatter radiation.
Decrease the penetrability of the beam and reduce the production of scatter radiation.
Using an air gap technique, increasing the OID also -decreases scatter and increases detail -increases scatter and decreases detail -decreases both scatter and detail -increases both scatter and detail
Decreases both scatter and detail
When using an air gap technique, increasing the OID also Decreases scatter and increases detail. Increases scatter and decreases detail. Decreases both scatter and detail. Increases both scatter and detail
Decreases both scatter and detail
Which of the following will increase image detail or sharpness? Decreasing the SID Decreasing the OID Decreasing the SOD Increasing the OID
Decreasing the OID
_________ is a universal standard value that reflects the difference between the desired or target exposure to the IR and the actual exposure to the IR. Exposure index Sensitivity number Deviation index Log median number
Deviation Index
_____ results in the process of image formation, when the x-ray beam interacts with the anatomic tissue, and a portion of the beam passes through the part and strikes the image receptor. -Transference -Differential absorption -Compensating filtration -Molecular modeling
Differential absorption
DICOM is an abbreviation for: Digital Imaging communication in management. Darn I can't control myself. Digital imaging communication in medicene. Developing interests in career motivation.
Digital imaging communication in medicene
The three things that will reduce your exposure to scatter radiation are: -Collimation, smaller body parts, and really low techniques -kVp, mA, and time -Collimation, attenuation, and distance -Distance, time, and sheilding
Distance, time and sheilding
Magnification, elongation, and foreshortening are three types of: -views -exams -excuses for a bad radiograph -distortion
Distortion
If an image is too light and needs to be repeated, it is recommended that you _____ the mAs before repeating the exam. Halve Triple Quadruple Reduce Double
Double
What would be the appropriate change in mAs if the kVp were decreased by 15% and the density needed to be maintained? Double the mAs Halve the mAs Use one fourth of the mAs No change would be necessary
Double the mAs
X-rays can: A- penetrate the human body B- be absorbed in the human body C- change direction in the human body D- A and B only E- All of the above
E- All fo the above
During x-ray production, the energy of then moving electrons is converted to A. kinetic energy B. thermal energy C. electromagnetic energy D. A and C E. B and C
E. B and C
Increasing the kVp will do which of the following? A. decrease the tube current B. increase the speed of the electrons C. increase the penetrability of the beam D. A and C E. B and C
E. B and C
If the body part is in the same plane as the image receptor and the beam is angled at the image receptor (not perpendicular), the result is: Elongation Magnification Foreshortening
Elongation
You should use the small focal spot when radiographing: Adult Abdomens Large patients Extremities Body parts that require a high mAs
Extremities
Digital image quality is improved with: A. larger size matrix B. larger size pixels C. smaller size matrix D. smaller size pixels E. A and B F. A and D G. C and D
F. A and D
An increase in the amount of unsharpness recorded on the image has what effect on the visibility of anatomic structures? A. Increased contrast of anatomic structures B. Decreased contrast of anatomic structures C. Increased overall visibility D. Decreased overall visibility E. A and C F. B and D
F. B and D
180 centimeters is about the same as 60 inches. True /False
False
800 mA at .02 seconds will create the same mAs as 400 mA at 0.8 seconds\ True/False
False
A good time to use AEC is when the radiographer is unable to accurately center the x-ray beam True/False
False
An adult's knee measuring 14 cm should be radiographed without a grid. True/False
False
Any technique that works well at 40" should also have the same results at 60". True/False
False
Because digital imaging has a large dynamic range, significantly lower than necessary x-ray exposure will still result in a quality image. True/False
False
Changing the kVp has no affect on the amount of radiation produced at the anode. True/False
False
If the entire back-up mAs is used during an exposure and the image is light in density, increasing the density control to +2 or +3 will supply the additional back-up mAs necessary for an optimal density. True/False
False
In order to produce a radiographic image with structural lines as accurate as possible, you must maximize the special resolution and distortion. True/False
False
Increasing SID without changing the OID will decrease image detail. True/False
False
More than 99% of the electricity used to make an exposure contributes to the production of x-rays. True/False
False
Photoelectric interactions are non-ionizing interaction and are not a risk to the patient. True/False
False
Quantum Mottle or Quantum noise is caused by overexposure to the imaging receptor. True/False
False
Quantum noise (Quantum mottle) is a result of too much scatter reaching the image receptor. True/False
False
The controlling factor for radiographic contrast is mAs. True/False
False
The direction that x-rays travel can not be altered when the x-rays interact with matter. True/False
False
The type of tube Roentgen was working with in his lab when x-rays were discovered was a fluorescent tube True/False
False
When a grid is employed during an exposure, patient dose decreases. True/ False
False
X-rays carry a negative charge that causes ionization. True/False
False
X-rays produce a slight tingling sensation when they enter the body True/False
False
You should use AEC for all exams including hands, feet, and other extremities. True/False
False
Which of the following does not have any affect on the density of a radiograph? mAs Filament size Distance SID kVp
Filament size
Which of the following terms could be defined as the instantaneous production of light only during an interaction between a type of energy and some element or compound? Phosphorescence Afterglow Glowing Fluorescence
Fluorescence
Which of the following will not change the amount of radiation that reaches the image receptor? Patient size Collimation Focal spot size SID
Focal Spot Size
If the beam is perpendicular to the image receptor and the body part is not in the same plane as the image receptor, the result is _____ of the image Elongation Magnification Foreshortening
Foreshortening
In order to produce x-rays, projectile electrons need to travel at a very high speed: From the cathode to the anode. From the anode to the cathode. From the anode to the rotor. From the focusing cup to the cathode.
From the cathode to the anode
In order to produce x-rays, projectile electrons need to travel at a very high speed: From the cathode to the anode. From the anode to the cathode. From the anode to the rotor. From the focusing cup to the cathode.
From the cathode to the anode.
The SI unit for measurement of absorbed dose is the: Roentgen Curie Gray Air Kerma
Gray
The SI unit for measurement of absorbed dose is the: -Roentgen -Curie -Gray -Air Kerma
Gray
The most damaging single factor for a tube is: -heat -leaving the machine turned off for long periods -using low kVp settings -using low mA settings
Heat
The most damaging single factor for a tube is: Heat Leaving the machine turned off for long periods Using low kVp settings Using low mA settings
Heat
Grid ratio is computed by: Width between the lines divided by the height of the lines. Weight of the grid. Number of lines per inch. Height of the lead lines divided by the width between the lines.
Height of the lead lines divided by the width between the lines.
The heat units produced by a single-phase machine can be computed by which equation? Hu = kVp x mAs x 1.41 Hu = mA x seconds x 1.35 Hu = mAs x kVp Hu = mAs/kVp x 1.35
Hu = mAs x kVp
The heat units produced by a three-phase machine can be computed by which equation? Hu= kVp x mAs x 1.41 Hu= mA x seconds x 1.35 Hu= mAs x kVp Hu= mAs/kVp x 1.35
Hu= mA x seconds x 1.35
Spatial resolution and recorded detail are significant factors in: -Image sharpness -Image contrast -Image brightness -Keeping your job
Image sharpness
The Exposure Indicator is a tool that reflects exposure to the: Patient Imaging Plate
Imaging Plate
Employing a grid into an exam will have the following effects: Decrease patient dose. Increase the price of the exam.
Improve contrast. Remove some of the scatter that might reach the image receptor. Increase patient dose.
Increasing the SID from 40" to 72", without changing any other factors other than increasing the technique appropriately, will cause two of the following five changes to take place. Increase magnification. Improve detail Decrease density Increase density Decrease magnification Reduce detail
Improve detail Decrease magnification
Which of the following is NOT a way to reduce the production of scatter radiation? Reduce the exposure field size Reduce the tissue thickness Increase the grid ratio Ask a patient with a large abdomen to lie prone instead of supine
Increase the grid ratio
You shoot an AP knee using 65 kVp @ 25 mAs at 40 inches. The Radiologist does not like the image because of motion. The chief tech says' "Do it over". You realize that 25 mAs was a long exposure. To shorten the exposure time and maintain image density, you should: Reduce the kVp by 15% and double the mAs Increase the kVp by 15% and don't change the mAs. Keep the same kVp and just cut the mAs. Increase the kVp and cut the mAs in half.
Increase the kVp and cut the mAs in half.
When magnification is increased while using an intensification tube, the patient's exposure ______. Increases Decreases Stays the same.
Increases
The presence of scatter radiation on an image: -decreases detail and increases contrast -increases detail and increases contrast -decreases detail and decreases density -increases density and decreases contrast
Increases density and decreases contrast
If you increase the mAs on the control panel, patient exposure _____ and density_______. Decreases, decreases Increases, decreases Decreases, increases Increases, increases
Increases, increases
Which of the following will decrease image detail? Increasing the SID Increasing the SOD Increasing the OID Decreasing the OID
Increasing the OID
The primary benefit of a large focal spot is: It utilizes less radiation to complete the same exam as a small focal spot. It created more heat, which increases the conversion efficiency of the target anode. Patient exposure will always be less when the large focal spot is used. It allows you to use larger techniques for larger body parts without longer exposure times.
It allows you to use larger techniques for larger body parts without longer exposure times.
The primary benefit of a large focal spot is: -It utilizes less radiation to complete the same exam as a small focal spot. -It creates more heat, which increases the conversion efficiency of the target anode. -Patient exposure will always be less when the large focal spot is used. -It allows you to use larger techniques for larger body parts without longer exposure times.
It allows you to use larger techniques for larger body parts without longer exposure times.
Image artifacts like zippers, jewelry, and buttons will show up as _____ areas on a radiograph. Light Dense Neutral fuzzy
Light
For optimal viewing with a monitor, which type is superior for medical imaging? Cathode ray tube Liquid crystal display
Liquid crystal display
What is the term used that describes the process of changing the pixel values to match those of the the histogram model? Look up tables Histogram analysis Rescaling Image editing
Look up tables
What is the result of imaging a thicker part or patient? -more Compton interactions -less Compton interactions -increased radiographic contrast -decreased fog -decreased scatter
More Compton interactions
Short scale contrast can be defined as: Many shades of gray An overly exposed image Mostly black and white with few shades of gray
Mostly black and white with few shades of gray
In a bucky (wall or table), the way that grid lines are removed from becoming a part of the final image is by: -moving the film during the exposure -moving the grid during the exposure -using longer SIDs -using focused grids
Moving the grid during the exposure
In order to keep the projectile electrons in a small area before completing an exposure, the focusing cup will exhibit a _______ charge. Positive Negative
Negative
In order to keep the projectile electrons in a small area before completing an exposure, the focusing cup will exhibit a _______ Positive charge Negative charge Neutral charge
Negative Charge
X-rays have an overall ____ charge. Positive Negative Neutral
Neutral
Increasing the mAs has _______ effect on the brightness of an image. No An inverse A direct No answer text provided.
No
X-rays were discovered on: Nov 1st 1898 Oct 8th 1890 Nov 8th 1895 Nov 8th 1900
Nov 8th 1895
If the x-ray beam is not centered to the grid, the result is: Off level grid cut-off Off center grid cut-off Upside down grid cut-off
Off center grid cut-off
The type of scatter or secondary radiation that is predominant below 75 kVp (and seldom exits the body) is: Photoelectric Thompson's Compton's
Photoelectric
The type of scatter or secondary radiation that is predominant below 75 kVp is: Photoelectric Thompson's Compton's
Photoelectric
The event that produces a type of scatter (or secondary radiation) that seldom exits the body is: -Photoelectric effect -Compton's scattering
Photoelectric effect
PACS is an acronym for: Photo archiving computer system Picture and computer storage Picture archiving and communication system. Pet and Caress selectively
Picture archiving and communication system
The anode end of the tube carries a _____ electrical charge Negative Neutral Positive None of the above
Positive
To extend the life of the x-ray tube, it is recommended that you: -Use higher mA stations and shorter exposure times -Hold down the rotor button for as long as possible -Press down on the rotor button while making the exposure as soon as possible -Wiggle the tube while it's energizing to in order to add torque to the tube
Press down on the rotor button while making the exposure as soon as possible
The term used to describe a lack of information caused by a less than optimal technique is: Quanity model Quantum mottle or Quantum Noise Density decay None of the above.
Quantum mottle or Quantum Noise
The purpose of the input screen on an image intensifier is to: Receive the x-rays and convert them into electrons. Transmit the x-rays towards the anode. Receive the x-rays and convert them into light photons. Reduce the scatter produced by the patient.
Receive the x-rays and convert them into light photons.
If you are using the AEC system and your image repeatedly comes out too light even after increasing the density control to +3, you should consider: Repositioning the patient so that the thickest body part is over the detector. Reposition the patient so that a thinner body part is over the detector. Keep the patient in the exact position and shoot again, and again, and again.
Repositioning the patient so that the thickest body part is over the detector.
Collimation can be defined as: Opening up the beam for a wider area of exposure. Restricting the beam to the necessary area of exposure. Filtering the weak photons out of the beam. Aiming the x-rays at the body part.
Restricting the beam to the necessary area of exposure
Collimation can be defined as: Restricting the beam to the necessary area of exposure. Filtering the weak photons out of the beam. Opening up the beam for a wider area of exposure. Aiming the x-rays at the body part.
Restricting the beam to the necessary area of exposure.
When the x-ray photon strikes an atom within the tissue being imaged and loses only part of its energy to an outer shell electron of that atom, the photon is said to have been ____ and undergone the ____. Transmitted, coherent effect Absorbed, photoelectric interaction Attenuated, photoelectric Scattered, Compton interaction
Scattered, Compton interaction
If an image is mostly black-and-white and has very few gray tones it is considered: Short scale contrast Long scale contrast
Short scale contrast
The space charge produced when you rotor up an x-ray tube is limited in size. This limiting factor is known as: -Thermionic emission -Electron attraction -Space charge effect -The tube current
Space Charge Effect
The x-ray photon that is scattered as a result of the Compton effect CANNOT: -be absorbed in the tissue, resulting in additional patient exposure -strike the image receptor and provide useful anatomic information -strike the image receptor without providing useful information -exit the patient, exposing persons near the patient
Strike the image receptor and provide useful anatomic information.
The post processing technique that removes superimposed structures so that the anatomic area of interest is more visible is known as: Edge enhancement Black/white reversal. Contrast enhancement. Subtraction.
Subtraction
The process in which AEC determines just how much radiation is necessary to produce a good image is which of the following: The AEC can tell by the weight of the patient just how much radiation is necessary in order to create a good image. The AEC has a pre-set limit that when detected by the ionization chamber(s) will shut off the timer and terminate the exposure. The AEC will use the entire 'back-up mAs' in order to create an optimal image. The AEC has pre-set techniques that are the same for every patient and every exam and will produce the same density if the patient is within normal size limit.
The AEC has a pre-set limit that when detected by the ionization chamber(s) will shut off the timer and terminate the exposure.
By placing an angle on the target anode, we can have a larger actual focal spot and still maintain a smaller effective focal spot. This is also known as: The Line Focus Principle Off Focus Radiation The Line Target Principle The Anode heel Effect
The Line Focus Principle
Attenuation can be defined as: The part of the primary beam that is transmitted. The part of the beam that creates the dark areas on a radiograph. The absorption and/or scattering of the beam.
The absorption and/or scattering of the beam
The area on the target where most of the projectile electrons strike the target anode is known as: -The effective focal spot -The actual focal spot -The spinning disk -The portal
The actual focal spot
Which of the following is NOT an advantage to switching over to a digital radiography system? -the electronic storage of images -the cost of the image receptors -reduction in the time it takes to do an exam -postprocessing adjustments
The cost of the image receptors.
Which equation should be employed when the SID of an exam is altered? The Density Maintenance Formula The Inverse Square Law The 15% Rule
The density maintenance formula
Contrast can be defined as: The difference in attenuation between two different areas. The difference in scattering between adjacent areas. The overall blackness of an image. The difference in densities between adjacent areas.
The difference in densities between adjacent areas.
The two currents that pass through an x-ray tube are: -the mA and the pA -the filament and the tube current -the cathode and the anode -the filament current and the collimator circuit
The filament and the tube current
The two currents that pass through an x-ray tube are: The mA and the pA The filament and the tube current The cathode and the anode The filament current and the collimator circuit
The filament and the tube current
A focused grid is different than a parallel grid in that: -the grid lines on a focused grid are angles to match the divergence of the beam -the grid lines on a parallel grid are angled to match the divergence of the beam -the focused grid will have more grid lines than a parallel grid
The grid lines on a focused grid are angled to match the divergence of the beam
Grid ratios are determined by: -the height of the lead strips and the distance between them -the overall outside dimensions of the grid -the ratio is determined by the focal distance for that grid -the number of lead lines per inch
The height of the lead strips and the distance between them
Decreasing the kVp will alter the contrast of an image in which way? -The image becomes more gray with long-scale contrast. -The image becomes more black and white with short-scale contrast. -None of the above. kVp has no affect on contrast.
The image becomes more black and white with short-scale contrast
If you increase the distance between your patient and the image receptor, what two other things will also happen? -The image of the part will become smaller and the image detail will improve in sharpness. -The image will become magnified and the detail or sharpness will be decreased. -Nothing will happen as long as you don't change the SID. -Both image size and image detail will increase.
The image will become magnified and the detail or sharpness will be decreased.
The mathematical equation used to measure the change in intensity of the beam at different distances is: The Density Maintenance Formula The 15% Rule The Grid Conversion Factor The Inverse Square Law
The inverse square law
By placing an angle on the target anode, we can have a larger actual focal spot and still maintain a smaller effective focal spot. This is also known as: -The anode heel effect -Off-focus radiation -The line target principle -The line focus principle
The line focus priciple
Beam quantity refers to: -The penetrability of the beam -The energy level of the beam after filtration -The number of x-rays produced during the exposure process -None of the above
The number of x-rays produced during the exposure process
Beam quantity refers to: The penetrability of the beam The energy level of the beam after filtration The number of x-rays produced during the exposure process None of the above
The number of x-rays produced during the exposure process
Increasing the collimation of the beam (reducing the field size) will have which of the following effects? (Select all that apply) - The patient's exposure will be reduced. -Contrast will increase. -Overall density will increase slightly. -Scatter will be reduced. -None of the above.
The patient's exposure will be reduced Contrast will increase. Scatter will be reduced.
Increasing the collimation of the beam (reducing the field size) will have which of the following effects? (select all that apply) The patient's exposure will be reduced. Contrast will increase. Overall density will increase slightly. Scatter will be reduced. None of the above.
The patient's exposure will be reduced. Contrast will increase. Scatter will be reduced.
Ionization of an atom can be defined as: -adding an electron to an atom and changing it's molecular weight -the removal of an electron from an atom creating an ion with a positive charge -transmitting enough energy to an atom that it becomes an isotope -removing energy from an atom in order to create x-rays
The removal of an electron from an atom creating an ion with a positive charge.
X-rays travel at: 1/2 the speed of light in a vacuum. The speed of light in a vacuum. The speed of sound in a vacuum. The speed of light
The speed of light in a vacuum
The only part of the x-ray tube that is external to the housing and is used primarily to drive the rotor is: -The cathode -The anode -The focusing cup -The stators
The stators
Inherent filtration can be defined as: -The filtration added to the unit to complete the necessary 2.5 mm equivalent needed to be compliant to federal law. -The filtration that creates a stronger beam at the cathode end of the tube and a weaker beam at the anode end. -The unremoveable filtration created by the glass and oil between the focal spot and the patient. -A removable filter that can be used to increase the overall energy of the beam.
The unremoveable filtration created by the glass and oil between the focal spot and the patient.
If a patient has a metal prosthesis in their hip, what will it look like on a radiograph? -the metal area will be dark since it attenuated most of the beam -there will be a white or clear area that is the same shape as the prothesis -the prothesis image will be the same density as the bone and the surrounding tissues -since the beam cannot penetrate metal, there will be no image on the film
There will be a white or clear area that is the same shape as the prothesis.
_____ is the boiling off of electrons from the filament when current is applied. Saturation emission Thermionic emission Proton emission The portal
Thermionic emission
The purpose of a grid is: -to improve contrast -increase exposure to the image receptor -to reduce patient exposure -all of the above
To improve contrast
What is the purpose of setting a back up time/mAs? To prevent excessive exposure of the patient To make certain the contrast is acceptable if the chosen kVp is too low To make certain the density is acceptable if the patient moves To prevent the selection of the wrong detector
To prevent excessive exposure of the patient
What purpose does positive beam limitation (PBL) serve? -to prevent first-year students from having to repeat studies by not aligning the Bucky tray with the image receptor -to prevent the technologist from placing an image receptor in the Bucky tray that is too large for the study performed -to allow the technologist to use an exposure field larger than the image receptor size -to reduce patient exposure by limiting the exposure field to the same size as the image receptor in the Bucky tray
To reduce patient exposure by limiting the exposure field to the same size as the image receptor in the Bucky tray
What purpose does positive beam limitation serve? To prevent the technologist from placing an image receptor in the Bucky tray that is too large for the study performed To allow the technologist to use an exposure field larger than the image receptor size To prevent first-year students from having to repeat studies by not aligning the Bucky tray with the image receptor To reduce patient exposure by limiting the exposure field to the same size as the image receptor in the Bucky tray.
To reduce patient exposure by limiting the exposure field to the same size as the image receptor in the Bucky tray.
A histogram is a graph showing the intensities of the different pixel values. True/False
True
All x-rays have some form of distortion True/False
True
Any increase in magnification results in a decrease in recorded detail. True/False
True
Decreasing kVp by 15% and doubling the mAs will maintain the density of an image. True/False
True
Digital imaging receptors are more sensitive to scatter radiation than conventional film/screen systems. True/False
True
In an intensification tube, the photo cathodes purpose is to absorb the light photons and emit electrons towards the anode end of the tube. True/False
True
In order to be effective, grids are placed between the patient and the image receptor. True/False
True
In the event that the radiographer determines the recorded detail of an image is not adequately visualized and the image is unacceptable, the study must be repeated. True/False
True
Increasing OID without increasing the SID will reduce image detail. True/False
True
It is possible for x-rays to interact with matter and produce secondary radiation. True/False
True
It is the radiographer's responsibility to minimize the radiation dose to the patient, to themselves, and to others with As Low As Reasonably Achievable (ALARA) principle. True/False
True
Once the data is in digital format, there is no difference between image processing and display between CR and DR. True/False
True
Operating the fluoroscope in a pulsed mode will reduce the number of images each second, decrease patient dose, and reduce the visibility of patient motion. True/False
True
Quantum Mottle is an effect that can be seen on both CR and DR, and film. True/False
True
Quantum Noise is the term used to describe a grainy appearance caused by poor penetration of the body part. True/False
True
Screening for pregnancy is an important task for minimizing unnecessary exposure to a developing fetus True/False
True
The area on the target that is seen from viewing into the port of the tube and is angled to increase resolution is known as the effective focal spot. True/False
True
The cathode end of an x-ray tube has an overall negative charge. True/False
True
The direction that x-rays travel can be altered when the x-ray interacts with matter. True/False
True
The focal distance for a linear focused grid is determined by point in which the divergency of the lead lines intersect. True/False
True
The two types of digital imaging systems used for producing digital radiographs are DR and CR. True/False
True
The type of grid that the lead lines are angled to match the divergency of the x-ray beam is known as a linear focused grid. True/False
True
The x-ray beam produced with 120 kVp will consist primarily of x-rays produced by bremsstrahlung interactions True/False
True
The x-ray image is created by differential absorption of the x-ray beam as it passes through the body part. True/False
True
Thermionic emission takes place in the focusing cup of the x-ray tube. True/False
True
Using the 15% rule twice to increase a technique will essentially create the same density as increasing the mAs by a factor of 4. True/False
True
With digital image processing, increasing kVp for an AEC exposure will not significantly alter image contrast. True/False
True
X-ray energy can be described as waves. Wavelength and frequency are inversely related. If the wavelength increases, the frequency of the waves decreases. True/False
True
X-rays are capable of interacting with matter and producing secondary x-rays in the form of scatter radiation. True/False
True
X-rays are capable of interacting with matter and producing secondary x-rays in the form of scatter radiation. True/ False
True
X-rays cannot be focused with a lens. True/False
True
The filament is made of tungsten rhenium molybdenum lead nickel
Tungsten
What type of grid cut off will result in the lateral edges of the IR highly underexposed. -off focus grid -off center grid -off level grid -upside down focused grid
Upside down focused grid
When making an exposure, which of the following does NOT occur when just the rotor, or prep button, is activated? -The anode begins to rotate -Voltage is applied across the tube. -Current is applied to the filament -A space charge is created
Voltage is applied across the tube
If you are using all three detectors and if the back-up mAs is not exhausted, the exposure will terminate when: When only one of the detectors reaches the trigger termination point. When the average of all three detectors reaches the trigger termination point. The exposure will not shut off until the back-up mAs is exhausted.
When the average of all three detectors reaches the trigger termination point.
The first Medical X-rays performed in the United States were; -within 3 weeks of the discovery of X-rays -within 4 months of the discovery of X-rays -not until after the turn of the century -actually, it was before Roentgen discovered x-rays
Within 4 months of the discovery of X-rays
Which of the following is NOT a property of x-rays? X-rays travel at the speed of light X-rays travel in straight lines X-rays cannot be felt X-rays can bounce off a mirror
X-rays can bounce off a mirror
Which of the following is NOT a property of x-rays: X-rays can make you glow X-rays travel in straight lines X-rays act like both waves and particles X-rays cannot be felt
X-rays can make you glow
What process is employed to maintain consistent digital image brightness for overexposure or underexposure? Automatic rescaling Histogram Exposure Indicator Lookup Tables
automatic rescaling
Which of the following is not a function during post-processing of a displayed digital image? Automatic rescaling Electronic masking Windowing Edge enhancement
automatic rescaling
The radiographic grid is located inside the x-ray tube between the tube and patient between the patient and the IR beneath the IR
between the patient and the IR
The most common cause for repeating images done with AEC is inaccurate kVp selection backup mAs selection centering alignment of the tube and image receptor
centering
When using programmed techniques intended for adults (no AEC) and your patient is a small pediatric, you should: Use the suggested technique. Increase the technique. Decrease the technique. None of the above.
decrease the technique
Decreasing the window level will result in an image with lower contrast higher contrast decreased brightness increased brightness
decreased brightness
As beam restriction increases, the quantity fo scatter radiation ________ and radiographic contrast ______________ increases; increases decreases; increases decreases; decreases increases; decreases
decreases; increases
___________ imaging is accomplished with fluoroscopy as opposed to radiography Static Still Dynamic Colorized
dynamic
The output screen absorbs the _________ and emits light photons in proportion to the radiation that exited the patient. X-rays Images Electrons Atoms
electrons
The computed radiography (CR) latent image consists of: electrons trapped in the phosphor layer clumps of metallic silver in the emulsion light trapped int he phosphor layer the image as seen on the display monitor
electrons trapped in the phosphor layer
The numerical value that is displayed on the processed image to indicate the level of x-ray exposure received on the digital image receptor is the ____________ image brightness exposure indicator accession number optical density
exposure indicator
AEC eliminates the need for the radiographer to select the actual ________ the examination will require. kVp SID exposure time focal spot size
exposure time
Which of the following is easier to move around and allows better access to the patient during a procedure? Conventional image intensifier Flat-panel detector There is no difference between the two Amphorus Silicon
flat-panel detector
Which of the following terms could be defined as the instantaneous production of light only during an interaction between a type of energy and some element or compound? fluorescence after glow Phosphorescence none of these
fluorescence
ABC or Automatic Brightness Control is associated with: Monitor brightness controls AEC Fluoroscopy
fluoroscopy
Which of the following is a correct description of the relationship between the wavelength and frequency of the x-ray photon? wavelength and frequency are directly proportional wavelength and frequency are inversely related by the square root of lambda frequency and wavelength are inversely related wavelength and frequency have no relationship to each other
frequency and wavelength are inversely related
The electrical energy applied to an x-ray tube will be transformed to: -heat -light -x-rays -heat and light -heat and x-ray
heat and x-ray
An x-ray beam that has photons with many different energies is: -heterogeneous -monoenergetic -homogeneous -never found
heterogeneous
Tungsten has a ________ atomic number and a _________ melting point. low; low low; high high; low high; high
high; high
In order to reduce patient exposure, _________ kVp and _________ mAs should be used when possible. lower, higher higher, higher higher, lower It makes no difference
higher, lower
Window level controls: Image contrast Image brightness Both of the above.
image brightness
The device that received the radiation leaving the patient is the central ray differential absorption image receptor compensation filtration
image receptor
The newest fluoroscopy systems use a flat-panel detector: to display the spot images during fluoroscopy to record the overhead images following fluoroscopy in place of the image intensifier
in place of the image intensifier
When using AEC with digital imaging systems, assuming all other factors are correct, selecting the center chamber on a PA chest image results in_____________ decreased exposure in the lung area increased exposure in the lung area appropriate exposure in the lung area increased quantum noise in the lung area
increased exposure in the lung area
The photoelectric effect involves the removal (ejection) of an electron. This process of removing an electron from an atom is known as attenuation transmission ionization differential absorption
ionization
On the x-ray emission spectrum, the energy of the x-ray beam is measured in: mAs mA kVp kEv
kEv
With fluoroscopy, when the image exposure is too low to create an acceptable image, the ABC increases the ____ until the density is adequate. kVp mAs Filament size mA
kVp
As compared to a patient with a 24 cm thick abdomen, imaging a patient with a 20 cm thick abdomen will result in _________ scatter being produced and __________ image contrast less; lower more; lower less; higher more; higher
less; higher
In comparison, the vidicon camera tube has _______ spatial resolution, and the CCD requires ___________ radiation to produce a good fluoroscopic image. less; more less; less better; more better; less None of the above.
less; less
Increasing the window width will result in an image with: lower contrast higher contrast decreased brightness increased brightness
lower contrast
The primary controlling factor for beam quantity is: kVp mAs Film speed Grid ratio
mAs
A combination of rows and columns (array) of pixels is called a: matrix field of view voxel liquid crystal display
matrix
The measure of the imaging systems' ability to display the contrast of anatomic objects varying in size is the: spatial frequency modulation transfer function maximum intensity minimum intensity
modulation transfer function
The greater the pixel bit depth, the __________ the digitization of the analog signal, and the _________ the number of shades of gray available for image display. more precise; greater less precise; greater more precise: lesser less precise; lesser
more precise; greater
Conversion factor is a(n) _____________ term for brightness gain and is typically about ________ of the brightness gain value. older, 1% older, 10% newer, 1% newer, 10%
newer, 1%
If you use the center detector of a wall bucky when doing a PA chest, the resultant image will probably be ______. Under exposed Over exposed Of optimal density
over exposed
The mAs readout is of little value because it's not necessary to know mAs when using AEC reports the actual mAs used for an exposure reports the patient dose for the entire imaging study allows the radiographer to better set the mAs for an AEC examination
reports the actual mAs used for an exposure
When making a digital radiograph, the computer samples the histogram and adjusts the data to produce an optimal image. This adjustment process is known as: Realignment Rescaling Histogram adjustment Technique filtering
rescaling
When the x-ray photon strikes an atom within the tissue being imaged and loses only part of its energy to an outer shell electron of that atom, the photon is said to have been _____ and undergone the _____. Transmitted, coherent effect absorbed, photoelectric interaction attenuated, photoelectric interaction scattered, Compton interaction
scattered, Compton interaction
Which exposure variable is controlled by the automatic exposure control device? kVp Focal spot size Seconds mA
seconds
When doing a tabletop forearm study, you should Use AEC set manual technique A and B
set manual technique
Increased quantum noise is seen in a digital image with severely lower-than-needed mAs a little lower-than-needed mAs a little higher-than-needed mAs severely higher-than-needed mAs
severely lower-than-needed mAs
A method of describing the strength of the radiation exposure compared with the amount of noise apparent in the digital image is the: signal-to-noise ratio contrast-to-noise ratio modulation transfer function detective quantum efficiency
signal-to-noise ratio
Magnification of the fluoroscopic image results in improved brightness spatial resolution contrast exposure
spatial resolution
Overexposing a digital image receptor may result in a quality image, but quantum noise will be visible the SNR will be poor the ALARA principle has not been followed the system will not last as long as expected
the ALARA principle has not been followed
After making an exposure using AEC, what will tell you that you over or under exposed the image? The density of the image on the monitor. The mAs readout. The exposure index number. The tech standing behoind you.
the exposure index number
The exposure value index number is directly related to: The exposure received by the patient. The exposure received by the plate. The mAs chosen on the control panel. The distance between the source of the x-rays and the imaging receptor.
the exposure received by the plate
The letter x in x-ray is the symbol for: -electricity -the unknown -penetrating -discovery
the unknown
When the necessary radiation has been detected by an ionization chamber, the exposure is terminated at the _____. kVp control mA selector Power source Timer
timer
If the detector is directly exposed to the primary beam, the area of interest will appear overexposed underexposed correctly exposed to have a high contrast
underexposed
A loss of brightness around the edge of the fluoroscopic image due to the curve fo the photocathode is noise pincushion appearance vignetting magnification
vignetting
All electrons have an overall negative charge so they ____ each other. will repel are attracted to none of the above
will repel
In conjunction with ALARA, which of the following cardinal principles help to minimize radiation exposure? 1. Shielding-maximize use of shielding from ionizing radiation 2. Time-decrease time exposed to ionizing radiation 3. Time-increase time exposed to ionizing radiation 4. Distance-decrease distance from ionizing radiation 5. Distance- increase distance from ionizing radiation 1, 2, and 5 1, 3, and 4 1, 3, and 5 1, 2, and 4
1, 2, and 5
In order to decrease your kVp by 15%, you should multiply your kVp by: 1.15 .85 15 85
.85
In order to decrease your kVp by 15%, you should multiply your kVp by: 1.15 .85 15 85
.85
Where a typical diagnostic tube operates at 50 - 1200 mA, the fluoroscopic mA range is ________ mA. 50 - 500 100 - 1200 0.5 to 5.0 200 - 300
0.5 to 5.0
The amount of detectors found in an input screen of an Fluoroscopic image intensifier is: 1 2 3 4
1
Size distortion is affected by 1. SID 2. OID 3. Tube angulation 1 and 2 only 1 and 3 only 2 and 3 only 1, 2, and 3
1 and 2 only
Which of the following practices will extend the life of the X-ray tube? 1. Use low mA and longer exposure time 2. Warm up the tube as appropriate 3. Hold down the rotor button for a long time, to keep the tube warmed up 1 and 2 only 1 and 3 only 2 and 3 only 1, 2, and 3
1 and 2 only
A digital image with decreased spatial resolution may be due to: 1. Increased central ray angulation 2. Decreased grid ratio 3. Decreased SID 1 and 2 only 1 and 3 only 2 and 3 only 1, 2, and 3
1 and 3 only
Assuming no other changes are made, which of the following would result in increased quantum noise in a digital image? 1. Decreasing mAs 2. Increasing kVp 3. Imaging a thicker part 1 and 2 only 1 and 3 only 2 and 3 only 1, 2, and 3
1 and 3 only
If an object is radiographed at an SID of 80 cm and the object is 20 cm from the image receptor, the magnification factor for the image will be (SID/SOD = MF): 1.2 1.333 1.4 1.5
1.333
If your input screen has a diamter of 12 inches and you are utilizing an area with a 9 inch diameter, your magnification factor is: 1.25 1.5 1.333 1.67
1.333
The rectification number for computing heat units when operating a three-phase six-pulse x-ray machine is: 1 1.35 1.40 1.45
1.35
If your input screen has a diamter of 9 inches and you are utilizing an area with a 6 inch diamter, your magnification factor is: 1.33 1.66 1.5 1.25
1.5
Grids are usually employed when the body part thickness is greater than: 4 cm 10 cm 6 cm 5 cm
10 cm
You are going to do a chest x-ray on a patient in the intensive care unit. This patient is on a ventilator and cannot hold their breath. The last time this exam was done on this patient, the technique was 90 kVp at 8 mAs. The chest x-ray is being repeated because although the density was good, there was breathing motion. You can employ the 15% rule to reduce the exposure time. Which technique will do this without altering density? 76 kVp @8 mAs 90 kVp @4 mAs 115 kVp @4 mAs 104 kVp @ 4 mAs
104 kVp @ 4 mAs
A technique of 20 mAs with a 12:1 grid will be equal to ____ mAs when using a 6:1 grid. 8 10 16 12
12
A technique of 75 kVp at 60 mAs was used on an abdomen at an SID of 40 inches. What would you need to change your technique (mAs) to if your SID was increased to 56 inches? 80 mAs 120 mAs 60 mAs 100 mAs
120 mAs
Using which of the following grid ratios will increase patient exposure to radiation the most? 12:1 8:1 6:1 4:1
12:1
Which of the following grid ratios will remove the most amount of scatter radiation? 5:1 6:1 8:1 12:1
12:1
Using the density maintenance formula, if you produce an AP chest x-ray at 40" using 100 kVp @ 4 mAs, what will your mAs be if you increased your SID to 72 inches and the kVp remained the same? 13 mAs 10 mAs 16 mAs 18 mAs 24 mAs
13 mAs
Using the density maintenance formula, if you produce an AP chest x-ray at 40" using 100 kVp @ 4 mAs, what will your mAs be if you increased your SID to 72 inches and the kVp remained the same? 13 mAs 10 mAs 16 mAs 18 mAs 24 mAs
13 mAs
An exposure done on a high frequency x-ray machine of 110 kVp (rectification of 1.40) at 88 mAs will produce _____ heat units. 9680 13,068 13,552 14,036
13,552
An exposure of 200 mA for .60 seconds at 88 kVp will produce _____ heat units when done on a high frequency (1.40) x-ray machine. 5,540.4 9,888.2 1490.8 14,784 None of the above
14,784
An exposure of 200 mA for .60 seconds at 88 kVp will produce _______ heat units when done on a high frequency (1.40) x-ray machine. 5,540.4 9,888.2 1,490.8 14,784 none of the above
14,784
The first radiograph produced by Roentgen, of his wife's hand, required an exposure time of 15 s 150 s 15 min 150 min
15 min
The back-up mAs for any exam when using the AEC should be no less than: 50% of the anticipated amount of exposure. 100% of the anticipated amount of exposure. 150% of the anticipated amount of exposure.
150% of the anticipated amount of exposure
What is the grid ratio when the lead strips are 3.2mm high and separated by 0.2mm? 16:1 6:1 8:1 12:1
16:1
72" is equal to _____. 180 cm 150 cm 120 cm 100 cm
180 cm
X-rays were discovered in what year: 1895 1890 1898 1896
1895
A digital image with increased distortion may be due to: 1. Decreased OID 2. Increased CR angulation 3. Decreased SID 1 and 2 only 1 and 3 only 2 and 3 only 1, 2, and 3
2 and 3 only
Patient dose increases when: 1. Changing from a higher to lower grid ratio 2. Changing from a lower to higher grid ratio 3. A grid is used 1 and 2 only 1 and 3 only 2 and 3 only 1, 2, and 3
2 and 3 only
What is the appropriate change in kVp when using a variable kVp-fixed mAs technique chart for a 1 cm change in tissue thickness? 2 kVp 4 kVp 6 kVp 10 kVp
2 kVp
Which of the following is the sequence of events, from beginning to end, of what happens in the CR reader unit? 1. Analog electrical signal is sampled and digitized. 2. Stored energy is released as visible light. 3. PMT converts light to electrical signal. 1, 2, 3 2, 3, 1 1, 3, 2 2, 1, 3
2, 3, 1
The US Government states that all x-ray machines capable of 70 kVp of higher must have a total filtration of: 2.5 mm of aluminum 2.5 mm of aluminum or the equivalent 2.5 mm of added filtration none of the above
2.5 mm of aluminum or the equivalent
The US Government states that all x-ray machines capable of 70 kVp or higher must have a total filtration of 2.5 mm of aluminum 2.5 cm of aluminum or the equivalent 2.5 mm of added filtration 2.5 mm of aluminum or the equivalent
2.5 mm of aluminum or the equivalent
You use 50 mAs with a 12:1 ratio grid, what mAs will you use with a 5:1 ratio grid to produce the same exposure to IR. 125 40 10 20
20
You x-rayed a large knee using 65 kVp at 5 mAs. If you were to do this same exam with an 8:1 grid, the mAs would need to be increased to: 12 mAs 16 mAs 20 mAs 24 mAs
20 mAs
If the leakage radiation from a tube housing measures 80 mR at a distance of .5 meters, how much will the measurement be if done at 1 meter? (hint - use the Inverse Square Law) 20 mR 40 mR 120 mR 160 mR
20 mR
If 80 kVp at 40 mAs works well at 36", which change in mAs will create the same density at 80"? 100 mAs 120 mAs 160 mAs 200 mAs Oh crap, I have no clue....
200 mAs
A radiographer produced a humerus image with a non grid exposure using 6 mAs and then wanted to use a 8:1 ratio grid, what is the new mAs? 30 24 12 36
24
On a wall bucky, how many AEC ionization chambers are there? 1 2 3 4
3
There are ___ ionization chambers found in a wall or table Bucky. 1 3 2 4
3
The SSD should be no less than _______ for a fixed or stationary fluoroscopy unit and no less than _______ for a mobile fluoroscopic unit (C-arm). 38 cm; 30 cm 30 cm; 38 cm 38 in; 30 in 30 in; 38 in
38 cm; 30 cm
10% of 100 cm is equal to _____ inches. 8 6 4 10
4
With any type of imaging system that utilizes radiation, if you double the distance between the image receptor and the x-ray source, you need to increase your mAs by a factor of ___. 1 2 3 4 6
4
Size distortion is affected by 1. SID 2. OID 3. Tube angulation -1 and 2 only -1 and 3 only -2 and 3 only -1, 2, and 3
4. 1 and 2 only
Using the density maintenance formula, a technique 60 kVp @ 12 mAs usually done at 40" will now be done at 24". What is your new mAs for this distance? 2.44 8.42 mAs 6.28 mAs 4.32 mAs
4.32 mAs
How much is the mAs when 400 mA and 100 ms are used? 4 mAs 40 mAs 400 mAs 4000 mAs
40 mAs
If a person stands 3 feet from the source of exposure, receives an exposure of 160 mR, and then moves to 6 feet from the source of exposure, what would be the new exposure according to the inverse square law? 10 mR 40 mR 640 mR 2560 mR
40 mR
Using the density maintenance formula, a technique of 80 kVp at 24 mAs with a 40" SID now has to be done at 56". What is the closest mAs setting for the new distance? 4 mAs 47 mAs 16 mAs 12 mAs
47 mAs
Using the density maintenance formula, a technique of 80 kVp at 24 mAs with a 40" SID now has to be done at 56". What is your new mAs setting for this new distance? 4 mAs 47 mAs 16 mAs 12 mAs 32 mAs
47 mAs
The Bucky factor for a grid with a 12:1 ratio is: 3 4 5 6
5
You perform a routine portable femur exam using 30 mAs with an 6:1 ratio grid, what mAs should be used if a 12:1 ratio grid is used? 24 33 50 40
50
All of the following techniques equal the same mAs but one of them will have the shortest exposure time. Which one is it? 200 mA x .05 seconds 100 mA x 1/10th second 400 mA x 25 milliseconds 500 mA x .02 seconds
500 mA x .02 seconds
An exposure of 60 kVp at 4 mAs is too dark and needs to be reduced to 1/2 its value. You can reduce the kVp by 15% without reducing the mAs to achieve this. If you employed the 15% rule to reduce the kVp to reduce density by 1/2, your new technique will be 51 kVp at 8 mAs 69 kVp at 2 mAs 60 kVp at 2 mAs 51 kVp at 4 mAs
51 kVp at 4 mAs
If you produced an acceptable image of a knee using 60 kVp @ 6 mAs at 40", what would your technique be you added another 20" to the SID and wanted to maintain the same density? 60 kVp @ 4.8 mAs 60 kVp @ 13.5 mAs 60 kVp @ 17.1 mAs 60 kVp @ 15.0 mAs
60 kVp @ 13.5 mAs
If you produced an acceptable image of a knee using 60 kVp @ 6 mAs without a grid, what would your technique be if you added an 6:1 ratio grid and wanted to maintain the same density? 60 kVp @ 10 mAs 60 kVp @ 18 mAs 60 kVp @ 12 mAs 60 kVp @ 16 mAs
60 kVp @ 18 mAs
Above 50 kVp, the back-up timer should terminate the exposure if: 2000 mAs has been used and the detectors have not terminated the exam. 50% of the back-up has been reached and the detectors have not terminated the exam. 600 mAs has been used and the detectors have not terminated the exam.
600 mAs has been used and the detectors have not terminated the exam.
You usually do your adult knees using 65 kVp at 4mAs without a grid. Today you decide to employ an 8:1 grid to gain better contrast and detail. Changing only the mAs, your new technique will be: 65 kVp @ 16 mAs 65 kVp @ 24 mAs 65 kVp @ 12 mAs 65 kVp @ 8 mAs
65 kVp @ 16 mAs
An exposure of 75 kVp @ 88 mAs from a single phase x-ray machine will generate _______ heat units. 5800 6600 7800 8100
6600
If your beam is 100% Bremsstruhlung radiation, this means that your kVp setting is up to but no greater than ____ kVp. 69 75 110 60
69
You are trying to x-ray a lower leg on a screaming combative 3 year old with a portable machine. Your technique is 60 kVp at 4 mAs is good for a child this size. To reduce your exposure time and maintain the density of the previous technique, you can employ the 15% rule to increase kVp and reduce mAs. What will your new technique be if you do this? 51 kVp at 8 mAs 69 kVp at 2 mAs 69 kVp at 4 mAs 78 kVp at 2 mAs
69 kVp at 2 mAs
You are trying to x-ray a lower leg on a screaming combative 3 year old with a portable machine. Your technique is 60 kVp at 4 mAs is good for a child this size. To reduce your exposure time and maintain the density of the previous technique, you can employ the 15% rule to increase kVp and reduce mAs. What will your new technique be if you do this? 69 kVp at 2 mAs 69 kVp at 4 mAs 78 kVp at 2 mAs 51 kVp at 8 mAs
69 kVp at 2 mAs
In order to produce characteristic radiation with a tungsten anode, your kVp setting must be ____ or greater. 60 kVp 70 kVp 80 kVp 110 kVp
70 kVP
You are about to x-ray an shoulder and your usual technique with a 6:1 grid is 70 kVp at 18 mAs. What will your new technique be if you do this same exam without a grid? 70 kVp @ 36 mAs 70 kVp @ 12 mAs 70 kVp @ 6 mAs
70 kVp @ 6 mAs
400 mA x .02 seconds = 800 mAs 80 mAs 8 mAs .8 mAs .08 mAs
8 mAs
If a technique using an 8:1 grid was 32 mAs, what would the mAs be for a non-grid technique if all other factors remained the same? 5 mAs 6 mAs 4 mAs 8 mAs
8 mAs
A technique of 75 kVp @ 20 mAs at a distance of 36" is equal to a technique of 75 kVp @ ____ mAs at a distance of 72". 10 80 40 5
80
Which of the following mA and exposure time combinations does not produce 12 mAs? 200 mA at 0.06 s 400 mA at 0.03 s 600 mA at 20 ms 800 mA at 0.15 s
800 mA at 0.15 s
On large patients, I like to do my portable chest x-rays at a distance of 10 feet instead of 72" because it reduces magnification. If 85 kVp at 3.2 mAs works at 72 inches, which of the following techniques will create the same density at 10 feet? 85 kVp at 8.9 mAs 85 kVp at 6.4 mAs 85 kVp at 1.9 mAs 85 kVp at 12.8 mAs
85 kVp at 8.9 mAs
If a person stands 12 feet from the source of exposure, receives an exposure of 60 mR, and then moves to 3 feet from the source of exposure, what would be the new exposure? 15 mR 45 mR 240 mR 960 mR
960 mR
When electrons strike the anode target, their kinetic energy is converted to ____% heat and ____% x-rays. 1; 99 99; 1 0; 100 100; 0 50; 50
99; 1
A histogram of an image is: The true image found within the collimation. Data that shows the kVp and mAs used to create the image. A graph displaying the pixel values for that exposure. The text portion of an image that details patient information.
A graph displaying the pixel values for that exposure
Effective compensation for the anode heel effect would involve positioning: A. the thinnest portion of the part under the anode B. the thickest portion of the part under the anode C. the thinnest portion of the part under the cathode D. B and C
A. The thinnest portion of the part under the anode
Effective compensation for the anode heel effect would involve positioning A. The thinnest portion of the part under the anode B. The thickest portion of the part under the anode C. The thinnest portion of the part under the cathode D. B and C
A. the thinnest portion of the part under the anode
Contrast is a quality related to the __________ of the radiographic image. A. visibility of structures B. accuracy of structural lines C. spatial resolution D. B and C
A. visibility of structures
In reference to image intensification, the function that adjusts and maintains the overall image brightness and contrast during fluoroscopic procedure is: DQE APR ABC AEC
ABC
____________ measures the transfer of radiation energy into matter exposure absorbed dose dose equivalent radioactivity
Absorbed Dose
The brightest areas of a radiograph are created by: Transmitted radiation Scatter radiation Primary radiation Absorbed radiation
Absorbed radiation
Electrostatic lenses are used to: Accelerate and focus the electrons on their way to the anode. Prevent the electrons from exiting the intensification tube. Convert photo electrons into light photons. Create the image through photo scintillation.
Accelerate and focus the electrons on their way to the anode.
Which of the following materials has the least attenuation value? -Air -Fat -Muscle -Metal
Air
400 milliseconds is equal to: 0.4 seconds 4/10ths of a second. 2/5ths of a second. All of the above.
All of the above
By adding filtration to the beam we are: -Removing the weaker x-rays from the beam. -Increasing the overall average energy of the beam. -Creating a safer beam. -Adding to the inherent filtration to achieve at least 2.5 mm of aluminum or the equivalent. -All of the above.
All of the above
By filtering the beam after it exits the tube, the result is: An increase in the overall average energy of the beam since the weaker x-rays were removed Less exposure to the patient without sacrificing image quality Removing the x-rays that probably would not be transmitted through the patient All of the above
All of the above
Which of the following will reduce the amount of scatter that reaches the image receptor? Decrease the kVp and increase the mAs. Collimate. Use a grid. All of the above.
All of the above
Which of the following will reduce the amount of scatter that reaches the image receptor? -Decrease the kVp and increase the mAs. -Collimate. -Use a grid. -All of the above.
All of the above
An artifact is: -an unwanted part of a radiograph -an important part of a radiograph
An unwanted part of a radiograph
Exit radiation is: -only the portion of the beam that passes through the patient to the image receptor -any radiation that exits the body. This includes scatter and transmitted x-rays. -the part of the beam that is outside the body part and should have been collimated -radiation that escapes the grid and fogs the film
Any radiation that exits the body. This includes scatter and transmitted x-rays.
Increasing the kVp will have what affect upon the contrast of an image? As kVp increases, contrast increases and becomes short scale contrast. As kVp increases, contrast decreases and becomes long scale contrast.
As kVp increases, contrast decreases and becomes long scale contrast.
Human tissue with a higher atomic number will: -Attenuate less radiation -Create scatter more easily -Stink alot if left if the fridge for more than a week -Attenuate more radiation
Attenuate more radiation
_____ is the loss of some of the energy from the x-ray beam as it passes through the tissue being imaged. -Attenuation -Compensating filtration -Photon transmission -Photoelectric scattering
Attenuation
Thicker body parts result in greater: Transmission of the beam. Attenuation of the beam. Both of the above.
Attenuation of the beam
