2335: Quizzes
Factors that influence the efficiency of a grid include: a. Grid ratio b. Grid frequency c. Lead content d. Grid radius e. All of the above
e. All of the above
The lead equivalence needed for the Bucky slot cover is at least a. .25 mm b. .35 mm c. .5 mm d. 1 mm
a. .25 mm
If a nuclear medicine tech received an absorbed dose of 50 mGy of gamma (WR=1) and 5 mGy of alpha (WR=20), what is the total equivalent dose in Sv? a. 0.15 Sv b. 5 Sv c. 25 Sv d. 5000 Sv
a. 0.15 Sv
The following parameters are used to produce a diagnostic image of the chest: 5 mAs, 80 kVp, 72" SID, 400 SC. If the tech performs the exam using a 200 SC system instead, what is the new technique that should be employed? a. 10 mAs b. 20 mAs c. 30 mAs d. 40 mAs
a. 10 mAs
A step up transformer has 400 coils in the primary and 50,000 turns in the secondary. What is the voltage generated in the secondary coil if the primary coil is supplied with 240 volts? a. 30 kVp b. 190 volts c. 300 volts d. 96 kVp
a. 30 kVp
When compared to the video camera positioned at the output phosphor, this device positioned at the output phosphor helps to create images with higher spatial resolution, higher signal to noise ratio (SNR), and better contrast resolution while permitting a lower patient dose. a. Charged coupled device (CCD) b. Input phosphor c. Ionization chamber d. Rectifier
a. Charged coupled device (CCD)
Which statement about Compton interactions is FALSE: a. Do not occur in the patient b. Contribute to the technologist exposure c. Occur in the outer shell d. Can affect the image
a. Do not occur in the patient
With image intensified fluoroscopy, the magnification mode is achieved by varying the voltage applied to the a. Electrostatic lenses b. Input phosphor c. Anode d. Photocathode
a. Electrostatic lenses
If the technologist doubles the mAs on an image without decreasing the kVp, the following is TRUE: a. Exposure is increased by 2x b. SID helps with shape distortion c. Size distortion has to do with the size of the Focal Spot
a. Exposure is increased by 2x
Compared to a high-frequency generator, single phase equipment requires ___________ patient doses in order to achieve diagnostic quality images. a. Higher b. Lower c. The same
a. Higher
Shape distortion on an image can be caused by: a. Inappropriate CR angle b. Incorrect cassette size c. Wrong focal spot selection d. Large OID
a. Inappropriate CR angle
The following parameters are used to produce a diagnostic image of the pelvis: 20 mAs, 80 kVp, 40" SID, 10:1 grid. If the patient is pregnant, what can be done to minimize the dose to the unborn child while maintaining IR exposure? a. Increase kVp to 92 AND reduce mAs to 10 b. Decrease the grid ratio to 12:1 and increase the mAs to 25 c. Change to 200 mA, 100 msec, 85 kVp d. Decrease the distance to 30" SID and increase the OID by 3"
a. Increase kVp to 92 AND reduce mAs to 10
The SID is changed from 40" to 72", what happens to image magnification? a. Increases b. Decreases c. Remains the same
a. Increases
The device that causes the anode to spin is: a. Induction motor b. Autotransformer c. Resistor d. Rotator coils
a. Induction motor
Identify the true statement about size & shape distortion? a. Magnfication of an object is size distortion and elongation/foreshortening is shape distortion b. A large OID gives an image shape distortion c. SID helps with shape distortion d. Size distortion has to do with the size of the Focal Spot
a. Magnfication of an object is size distortion and elongation/foreshortening is shape distortion
Exposure times less than the minimum response time of an AEC may be needed when a. Using high milliamperage on small patients b. Examining large patients or body parts c. Using low kVp on large patients d. Using low milliamperage on small patients
a. Using high milliamperage on small patients
The Fourier Transform is an algorithm used to: a. convert digital data from the spatial domain to the frequency domain b. estimate a known value from unknown values c. stretch the histogram d. convolute an image
a. convert digital data from the spatial domain to the frequency domain
With respect to the effects of ionizing radiation the most critical period during pregnancy is: a. first trimester b. second trimester c. third trimester d. just before birth
a. first trimester
The purposed of the Deviation Index is to: a. give feedback to the radiographer allowing for the tracking and adjustment of exposures b. increase the DQE of a digital system c. increase the effectiveness of the selected procedure algorithm d. tells the radiographer what kVp to use
a. give feedback to the radiographer allowing for the tracking and adjustment of exposures
Filtration is measured by a medical physicist once per year using a _____ measurement. a. half-value layer b. MFT c. 50% per mm aluminum thickness d. compensating filter
a. half-value layer
Flat-field non-uniformity: a. is the variance of the signal across the area of the image field b. separates multiple exposures taken on a single IP c. changes the look up table for the displayed image contrast d. separates areas of the image for histogram analysis
a. is the variance of the signal across the area of the image field
CR Systems acquire clinical information by: a. laser scanning a PSP plate b. gathering x-rays from a scintillator c. direct digital transformation of x-ray photon energy d. applying a charge to a TFT
a. laser scanning a PSP plate
After the initial stage, which stage of acute radiation syndrome (ARS) does the patient experience no visible effects for approx. 1 week? a. latent period b. recovery or death c. manifest illness d. prodromal
a. latent period
The amount of energy transferred from radiation to an object per unit length of track measured in keV/um: a. linear energy transfer b. radiation weighting factor c. target theory d. equivalent dose
a. linear energy transfer
Loss of contrast in digital imaging is most likely the result of: a. over penetration of the body part b. using higher grid ratios with mAs compensation c. increased subject contrast d. a decrease in scatter production
a. over penetration of the body part
The best way to reduce involuntary motion is to: a. reduce exposure time b. increase SID c. use a high frequency grid d. increase kVp and decrease mAs
a. reduce exposure time
A common feature between indirect and direct DR technology is: a. thin film technology (TFT) b. a scintillaion layer c. cassettes d. imaging plates (IP)
a. thin film technology (TFT)
The exposure rate during a C-arm procedure is measured at 4 mGy/hr at a distance of 1 m from the patient. What is the total exposure at same distance if the total fluoroscopy beam on time is 3 minutes? a. 0.067 mGy b. 0.2 mGy c. 4 mGy d. 12 mGy
b. 0.2 mGy
Coils exhibit self-induction: 1. During the "make" phase of DC 2. During the "on-phase" of DC 3. During 0-90 degree of the generator rotation a. 1 only b. 1 and 3 c. 2 and 3 d. 1, 2, and 3
b. 1 and 3
Select 2 technical parameters that will *most* reduce scatter noise on the image. 1. 6x6 collimated field 2. 10x12 collimated field 3. 6:1 stationary grid 4. 8:1 stationary grid a. 2 and 3 b. 1 and 4 c. 2 and 4 d. 1 and 3
b. 1 and 4
The Equivalent Dose Limit for occupational exposures for the lens of the eye: a. 5 mSv b. 150 mSv c. 200 mSv d. 500 mSv
b. 150 mSv
If a radiographer stands 6 m from the source at a dose rate of 2 mGy/hr; what is the dose rate if the radiographer moves 2 m from the source? a. 0.2 mGy/hr b. 18.0 mGy/hr c. 6.0 mGy/hr d. 3.0 mGy/hr
b. 18.0 mGy/hr
Misalignment between the collimator light field and the radiation field must not exceed _____% of the SID per exposure. a. 1 b. 2 c. 3 d. 4
b. 2
Quantum mottle would be *least* visible with the following operating conditions: a. 2 mAs, 75 kVp b. 200 mAs, 75 kVp c. 50 mAs, 80 kVp d. 10 mAs, 65 kVp
b. 200 mAs, 75 kVp
Which of the following techniques below will result in the most magnification? a. 60" SID, 2" OID b. 36" SID, 2" OID c. 40" SID, 1" OID d. 70" SID, 1.5" OID
b. 36" SID, 2" OID
A non-grid image is done using 10 mAs and 80 kVp. Which of the following techniques would be sufficient after employing a 12:1 grid? a. 40 mAs b. 50 mAs c. 20 mAs d. 60 mAs
b. 50 mAs
Which system can acquire images with the best resolution and lease amount of patient dose? a. 65% MTF; 35% DQE b. 85% MTF; 90% DQE c. 75% MTF; 25% DQE d. 30% MTF; 80% DQE
b. 85% MTF; 90% DQE
What type of filter allows IR exposure to be evenly distributed across an image when different tissue thicknesses are a concern? a. Inherent filtration b. Compensating filter c. Added filtration d. None of these
b. Compensating filter
A satisfactory image is produced using: 50mAs, 85 kVp, 40" SID, 16:1 grid. If the exam was repeated using 25 mAs, 75 kVp; what would happen to the IR exposure? a. Increase by 2x b. Decrease by 4x c. Increase by 4x d. Remain the same
b. Decrease by 4x
A computerized database of patients' health records: a. HL7 b. Electronic medical records system c. digital imaging communication in medicine d. health insurance portability and accountability act
b. Electronic medical records system
As part of the image intensification tube, the photocathode absorbs the light from the input fluorescent screen (input phosphor) and responds by emitting a. X-ray photons b. Electrons c. Visible green light d. Alpha waves
b. Electrons
During characteristic x-ray production, the following occurs: a. Low energy photons eject inner shell electrons in W b. Electrons are ejected from the inner energy levels of tungsten c. Electrons are ejected from the nucleus of tungsten atoms d. The closer the projectile electron passes to the nucleus, the greater the x-ray photon energy
b. Electrons are ejected from the inner energy levels of tungsten
The area of the digital matrix used for image reconstruction is called the: a. TFT b. FOV c. radiation field d. detector field
b. FOV
As the SID increases without compensation of the technique, the IR exposure will increase. a. True b. False
b. False
The objective of the ______ Campaign is to offer information on pediatric CT dose reduction. a. Image Wisely b. Image Gently c. NAS-BEIR d. Image No Child
b. Image Gently
In modern AEC devices, the ionization chamber is a gas-filled, 5 mm parallel plate that is placed before, or in front of the a. Fluorescent screen b. Image receptor c. The patient d. Collimator assembly
b. Image receptor
If a population is exposed to a lethal dose of radiation and 50% die within 30 days; this is referred to as: a. LD 30/50 b. LD 50/30 c. 50% collective effective dose d. 3-day late tissue effects
b. LD 50/30
Brightness gain is a product of a. Minification gain x flux loss b. Minification gain x flux gain c. Input screen diameter/output screen diameter d. Number of output light photons/number of input x-ray photons
b. Minification gain x flux gain
A (an) _______ database stores patients' health records, schedules and worklists for the radiology department. a. DICOM b. RIS c. operating system d. optical drive
b. RIS
Three-phase and high-frequency timers are evaluated using a a. Spinning top test b. Synchronous top c. HVL d. SMPTE pattern
b. Synchronous top
What can be done to improve quantum noise: a. Use low kVp b. Use the appropriate amount of mAs c. Use a high mA station d. Use a long SID
b. Use the appropriate amount of mAs
How can a radiographer best minimize scatter while performing a femur on a hypersthenic patient? a. Use a low-ratio grid b. Use tight collimation c. Use low mAs d. Use high mAs
b. Use tight collimation
Example(s) of early tissue reaction/s to high levels of radiation exposure include: a. breast cancer b. epilation c. genetic mutations d. a and c
b. epilation
The _______ is the average annual gonadal EqD to members of the population of childbearing years. a. general postulation dose b. general significant dose c. gonadal dose d. a and c
b. general significant dose
Which of these body parts has shortest scale contrast? a. KUB b. knee c. kidney d. liver
b. knee
What is the purpose of using a grid? a. facilitaties long scale contrast b. prevents scatter noise from reaching the IR c. focuses the x-ray beam to the center of the IR d. facilitates the x-ray beam to reach the IR
b. prevents scatter noise from reaching the IR
A PA chest displays very bright (light) on the display, the correct algorithm was used and the EI # is in range according the manufacture. The image is slightly off center, but all required anatomy is demonstrated. What is the most appropriate action? a. reprocess the image using a hand algorithm b. send the image to PACS without adjustments c. repeat the image w/ higher mAs d. adjust the window width
b. send the image to PACS without adjustments
If the DI is greater than +3, what is the most appropriate consideration for the radiographer? a. the EI # is in the correct range and the image can be sent to PACS w/o review b. the EI # is 100% higher than the target EI and the image needs further review c. The patient's ESE is too high and the image should be repeated with 1/2 the mAs d. the patient's doctor should e consulted, because the skin erythema will result from the exposure
b. the EI # is 100% higher than the target EI and the image needs further review
If a patient's stomach (WT=0.12) receives a dose of 0.06 Gy from fast nertrons (WR=20) what is the effective dose in Sv? a. 0.36 Sv b. 14.4 Sv c. 0.144 Sv d. 1.2 Sv
c. 0.144 Sv
The lead equivalency for a protective eyewear should be a minimum of _____. a. 1.0 mm b. 0.75 mm c. 0.35 mm d. 0.50 mm
c. 0.35 mm
Conventional image intensified fluoroscopy operates in the range of a. 10-15 mA b. 65 mA c. 0.5-5.0 mA d. 4-6 mA
c. 0.5-5.0 mA
With the following grid dimensions, determine the grid ratio: 5.0 mm high strips, 1.0 mm width of strips, and 0.5 mm width between the strips. a. 6:1 b. 5:1 c. 10:1 d. 16:1
c. 10:1
The following device(s) operate under the mutual induction principle: 1. autotransformer 2. step up transformer 3. rheostat 4. step down transformer a. 1 and 2 b. 2 and 3 c. 2 and 4 d. 3 and 4
c. 2 and 4
A radiographer standing 3 ft from the patient has a scatter dose of 0.25 mSv. What is the exposure if s/he stands 1 ft from the patient? a. 0.028 mSv b. 0.083 mSv c. 2.25 mSv d. 12 mSv
c. 2.25 mSv
The following parameters are used to produce a diagnostic image of the knee: 10 mAs, 64 kVp, and 40" SID, 200 SC. If the tech performs the exam at 56", what is the new technique that should be employed? a. 40 mAs b. 3 mAs c. 20 mAs d. 5 mAs
c. 20 mAs
An x-ray is performed using 80 kVp, 20 mAs, 100 cm SID, 8:1 grid. If the image is repeated using 180 cm SID instead, what is the new mAs needed to maintain the original exposure to the IR? a. 16 b. 6 c. 65 d. 36
c. 65
In target theory, the master molecule is: a. H20 b. repair proteins c. DNA d. all of the above
c. DNA
What technical changes can reduce exposure time? a. Reducing mA b. Increasing kVp c. Increasing grid frequency d. Both a & b
c. Increasing grid frequency
A _________ connects all the computers in a local network. a. WAN b. Interface protocol c. LAN d. CCD
c. LAN
Polyenergetic radiation is most likely to be emitted when: a. Projectile electrons interact with the nucleus b. Projectile electrons eject an outer shell W electron c. Projectile electrons are slowed down around the nucleus d. Projectile electrons interact and ejects a K shell W electron
c. Projectile electrons are slowed down around the nucleus
A transformer that has 300 primary coils and 150 secondary coils is a: a. Step-up transformer b. Autotransformer c. Step-down transformer d. High Tension Transformer
c. Step-down transformer
Falling load generators are often used in Cardiac Catheterization labs because: a. They produce better quality images then other generators b. They can achieve higher kVp settings than other generators c. They have better heat dissipation and recovery than other generators d. They produce images with less patient doses than other generators
c. They have better heat dissipation and recovery than other generators
A histogram is: a. a graph of the noise in a digital image b. a table of input values used to map output values c. a graph of the distribution of the pixel values in a digital image d. a graph plotting contrast as a function of detail in a digital image
c. a graph of the distribution of the pixel values in a digital image
Indirect DR typically uses _________ as the detector material. a. calcium tungstate b. amorphous selenium c. amorphous silicon d. CCD
c. amorphous silicon
An interaction of radiation with a H20 molecule that leads to second interaction with a nearby DNA molecule, is referred to as: a. relative biologic effectiveness b. a non-linear response c. an indirect effect d. an inverse effect
c. an indirect effect
How can a technologist effectively reduce the amount of scatter produced? a. decrease the grid ratio b. change the focal spot size c. collimate tightly to the part of interest d. have the patient hold their breath
c. collimate tightly to the part of interest
A linear dose response curve implies that the biologic response to ionizing radiations is: a. inversely proportional to the dose b. directly proportional to the square of the dose c. directly proportional to the dose d. inversely proportional to the square of the dose
c. directly proportional to the dose
In the technology of CR, the latent image is actually: a. sensitivity specks in the barium fluorohalide b. free electrons in the amorphous silicon c. electron "holes" in Europium d. electrical charges in TFT
c. electron "holes" in Europium
High PE absorption in human tissue will result in an image with ________ subject contrast, otherwise known as _________ contrast. a. high, long scale b. low, short scale c. high, short scale d. low, long scale
c. high, short scale
Noise from quantum mottle can be reduced by: a. increasing SID b. increasing grid ratio c. increasing mAs d. changing the procedure algorithm
c. increasing mAs
X-ray beam filtration reduces beam _____ but increases average beam _____ by providing significant reduction of very "soft" x-rays that contribute only to patient dose. a. quality; quantity b. hardness; intensity c. intensity; energy d. energy; intensity
c. intensity; energy
Space charge compensation occurs when: a. Collimation is changed b. SID is changed c. kVp is changed d. The x-ray tube is blown
c. kVp is changed
The response to radiation exposure with a digital receptor is: a. non-linear b. logarithmic c. linear with a threshold d. linear
c. linear with a threshold
The ALARA concept of radiation protection adopts the _____ dose-response curve with respect to the relationship between ionizing radiation and potential risk. a. nonlinear, non-threshold b. nonlinear, threshold c. linear, non-threshold d. linear, threshold
c. linear, non-threshold
When minor differences between gray shades are present on the image and many gray shades are visible, this is referred to as: a. brightness b. density c. long scale contrast d. short scale contrast
c. long scale contrast
Which set of technical factors below are more likely to increase the probability of photoelectric absorption in tissue? a. high kVp, low mAs b. low mAs, long SID c. low kVp, high mAs d. low kVp, high mAs
c. low kVp, high mAs
X-ray photon energy is directly related to a. photon velocity b. amperage c. photon wavelength d. focal spot size
c. photon wavelength
Image stitching is a ______ tool used to provide a seamless transition between two to three images "stitched" together: a. preprocessing b. for processing c. post processing d. noise reduction
c. post processing
Occupational dose is mostly caused by _____ radiation? a. primary b. leakage c. scatter d. a and c
c. scatter
Gray scale bit depth determines _______ of a digital system. a. pixel size b. pixel pitch c. the number of gray shades d. image magnification
c. the number of gray shades
The most effective way to protect the gonads from radiation is to: a. collimate to IR b. shield the gonads during a pelvis x-ray on a female patient c. use shielding when the gonads lie within 5 cm of the collimated beam d. a and b
c. use shielding when the gonads lie within 5 cm of the collimated beam
The lead equivalency for a thyroid shield should be a minimum of _____. a. 1.0 mm b. 0.75 mm c. 0.35 mm d. 0.50 mm
d. 0.50 mm
What is the pixel size of a 12 in digital image w/ a 512 matrix? a. 0.023 b. 30.4 c. 16.79 d. 0.59
d. 0.59
When can electromagnetic induction occur? 1. when a conductor is passed through a strong magnetic field 2. when a conductor is moved parallel to magnetic lines of force 3. when a moving magnetic field "cuts" through a stationary conductor a. 1 only b. 1 and 2 c. 2 and 3 d. 1 and 3
d. 1 and 3
A single-phase, half-wave rectified (HWR) x-ray machine creates an exposure using 400 mA, 200 ms, and 75 kVp. In total, how many pulses should be visualized using a spinning top test? a. 6 b. 8 c. 10 d. 12
d. 12
10 mAs and 85 kVp is used for a shoulder. Which of the following would result in doubling the exposure to the IR? a. 80 kVp b. 90 kVp c. 15 mAs d. 20 mAs
d. 20 mAs
A transformer has 200 primary turns and 32,000 secondary turns. The voltage in the primary coil is 240 volts and the current is 8 amps. What is the current in the secondary coil? a. 1280 amps b. 50 amps c. 128 mA d. 50 mA
d. 50 mA
Tools for measuring the focal spot size include: a. Pinhole camera b. Star pattern c. Slit camera d. All of the above
d. All of the above
Which methods reduce patient dose during mobile fluoro (c-arm) procedures? a. Use the spacer to prevent the tube from being placed <30 cm from the patient b. Position the c-arm so the x-ray tube in under the patient c. Use pulsed mode and low cine frame rates d. All of the above
d. All of the above
Which of the following factors affect image contrast? a. Scatter b. Beam restriction c. Pathology d. All of the above
d. All of the above
The function of image intensified fluoroscopy ensures that the exposure rate to the input phosphor is constant no matter the size of the patient and ensures that the image brightness level is always appropriate. a. Vignetting b. Backup timer c. Minimum response time d. Automatic brightness control (ABC)
d. Automatic brightness control (ABC)
This safety device will terminate the exposure if the AEC fails to do so. a. Anatomically programmed radiography (APR) b. Minimum response time (MRT) c. Last image hold d. Backup timer
d. Backup timer
Select the factor that can be used to describe details on an image? a. Sharpness b. Resolution c. Brightness d. Both a and b
d. Both a and b (sharpness & resolution)
Thermionic emission occurs at which of the following: a. Anode b. Stator c. Rotor d. Cathode
d. Cathode
_______ is a network communications protocol that electronically transfers medical images in the same format regardless of vendor: a. PACS b. HIPAA c. HL-7 d. DICOM
d. DICOM
The x-ray generator that demonstrates the least amount of voltage ripple from the choices below is: a. Single phase, 2 pulse generator b. 3 phase, 6 pulse generator c. 3 phase, 12 pulse generator d. High frequency generator
d. High frequency generator
A decrease in mAs will produce a decrease in: a. photon energy b. image resolution c. monitor brightness d. IR exposure
d. IR exposure
The agency that reviews studies of biologic effects of ionizing radiation and provides information to radiation protection organizations: a. ICRP b. NCRP c. OSHA d. NAS/NCR-BEIR
d. NAS/NCR-BEIR
An acceptable HIPAA-compliant action would include: a. Allowing someone else to use your PACS password to access images b. Using your network access to print your sister's mammogram report at her request c. Forgetting to logoff your workstation d. None of these are acceptable
d. None of these are acceptable
A device used to ensure reproducible radiographs regardless of tissue density variations is the a. Automatic exposure control (AEC) b. Stator c. Slit camera d. Pinhole camera
d. Pinhole camera
A system of computer software and hardware used for storage and transmission of digital images: a. screen contact test tool b. kVp test tool c. ABC resolution phantom d. SMPTE pattern
d. SMPTE pattern
The grid ratio is best defined as: a. The SID minimum and maximum that is required for a certain grid b. The size of the grid c. The amount of technique needed for a grid d. The ratio of the height of the lead strips to the width of the interspace material
d. The ratio of the height of the lead strips to the width of the interspace material
The term inductive reactance refers to: a. The work performed by a generator b. Energy consumed by a coil when powered by AC c. The storage capacity of a condenser d. The resistance characteristics of a coil in an AC circuit measured in Ohms
d. The resistance characteristics of a coil in an AC circuit measured in Ohms
Which diagnostic imaging procedures have reported early tissue effects from high radiation doses? a. cardiac catherization b. multiphase CT imaging c. routine chest x-ray d. a and b
d. a and b
Which of the following practices will increase occupational exposure during fluoroscopy? a. Using "high-level" fluoro b. Using pulsed fluoro c. Using a high frame rate in cine mode d. a and c
d. a and c
The following parameters are used to produce a diagnostic image of a hand: 2.5 mAs, 65 kVp, 40" SID. If the kVp was changed to 85, what would likely happen? a. involuntary motion b. inadequate IR exposure c. quantum mottle d. a loss of subject contrast
d. a loss of subject contrast
If you are not needed immediately by the radiologist or the patient, where should you stand during a fluoroscopic procedure? a. behind the radiologist b. behind the control booth barrier c. at the head of the x-ray table d. a or b
d. a or b
The thickness of protective barriers when designing an x-ray room, depends on: a. whether the area beyond the barrier is controlled or uncontrolled b. whether the barrier is primary or secondary c. workload, use factor and occupancy factor d. all of the above
d. all of the above
When using CR technology, it is important to remember that: a. the IP is extra sensitive to exposure after the initial xr exposure b. the IP will lose about 25% of its signal in 8 hours if not processed c. the IP is very sensitive to scatter, making grids very important d. all of the above
d. all of the above
Noise may be caused by: a. quantum mottle due to low mAs b. scatter radiation c. electronics d. all of these
d. all of these
The Internation Electrotechnical Commission (IEC) and the American Association of Physicists in Medicine (AAPM) developed the Deviation Index to: a. help vendors sell equipment b. increase spatial resolution c. compare patient doses from different systems d. develop a standard for exposure indexes for digital imaging systems
d. develop a standard for exposure indexes for digital imaging systems
Spatial resolution is improved with increased: a. SOD b. focal spot c. field size d. matrix size
d. matrix size
Changes to the average image brightness level of the displayed image to match the average image brightness level of the selected reference image are accomplished by: a. using a smoothing filter b. applying a medium contrast LUT c. using a global operation d. rescaling the histogram
d. rescaling the histogram
Which of the following will interfere with image interpretation on a digital display. a. radiation fogging b. pincushion distortion c. vignetting d. spectral and diffuse reflection
d. spectral and diffuse reflection
The operator adjustment on a digital imaging system that controls how many gray shades can be visualized on the digital display: a. slope or curve b. window level c. EI # d. window width
d. window width