Multiple Choice Questions
A.1
The characteristic(s) of computed tomography (CT) which give(s) it a distinct advantage over conventional radiography is/are:
a. Higher visibility of detail (resolution).
b. Better contrast sensitivity (low contrast detectability).
c. Lower noise.
d. Fewer artifacts.
A.2. The presence of noise in a medical image will generally:
a. Produce artifacts.
b. Produce blurring.
c. Reduce visibility of low contrast objects.
d. Produce image distortion.
A.3 Which of the following modalities does not use a form of ionizing radiation:
a. Radiography.
b. Computed tomography.
c. Sonography.
d. Positron emission tomography.
e. Magnetic resonance imaging.
A.4. Which of the following are units of energy:
a. joule.
b. Heat unit.
c. keV.
d. Watt.
A.5. The rest mass energy of an electron is used in:
a. X-ray production.
b. Calculation of radionuclide doses.
c. Determining Compton scattering.
d. Positron emission tomography.
A.6. If the body entrance field size in an abdominal spot film is increased from
20 cm by 20 cm to 40 cm by 40 cm and no other factors are changed, the:
a. Entrance surface exposure (in roentgens) will increase by a factor of 4.
b. Total radiation energy imparted to the patient will increase by a factor of 4.
c. Amount of scattered radiation will increase.
d. Radiation will be less concentrated because it is spread over a larger area.
A.7. Assume that a specific location on the surface of the body has received an
x-ray exposure of 5 roentgens. In order to determine the absorbed dose at that
point it will be necessary to know the:
a. Mass of the organ or tissue involved.
b. Spectral characteristics of the radiation.
c. Depth below the surface.
d. Type of tissue.
A.8. Assume that a scan of one CT slice produces an average dose of 3 rad to the
tissue in the slice. If 10 contiguous slices are scanned with the same factors:
a. The average dose to the tissue within the slice will increase by at least a factor of 10.
b. The integral dose (imparted energy) will increase by at least a factor of 10.
c. The risk to the patient will be increased.
d. Scattered radiation contributes to the dose
A.9. If soft tissue receives 100 roentgens of gamma radiation, this would
produce a dose or equivalent dose of approximately:
a. 100 rads
b. 1 gray
c. 37 millibecquerels
d. 1 sievert
A.10. The binding energy of a K-shell electron within an atom depends on:
a. The atomic number.
b. The mass number.
c. The chemical element.
d. The size of the atom.
A.11. Water is said to be "tissue equivalent" with respect to x-ray absorption.
This is because water and muscle have approximately the same:
a. Effective molecular weight.
b. Effective atomic number.
c. Electron density.
d. Physical density.
A.12. Two nuclides which are isobars will have the same:
a. Atomic number.
b. Mass number.
c. Number of neutrons.
d. Number of protons.
A.13. The characteristics which have an effect on the binding energy of a
specific electron include:
a. The size of the electron.
b. The size of the atom (atomic number).
c. The shell location (K, L, etc.).
d. The density of the material.
A.14. Nuclear transitions which directly produce photon radiation include:
a. Isotopic.
b. Isobaric.
c. Isomeric.
d. Electron capture.
A.15. Transitions which can produce electron particle radiation include:
a. Isobaric.
b. Isomeric.
c. Internal conversion.
d. Auger.
A.16. Radionuclides produced by a nuclear reactor are usually:
a. Alpha emitters.
b. Beta emitters.
c. Gamma emitters.
d. Positron emitters.
A.17. Cyclotrons are used to produce:
a. Beta emitters.
b. Positron emitters.
c. Electron capture nuclides.
d. None of the above.
A.18. Consider two radioactive samples which contain the same number of
radioactive nuclei but have different half-lives. The one with the longer
half-life will:
a. Have a higher activity.
b. Have a larger decay constant value.
c. Produce more total radiation.
d. Have a longer biological half-life.
A.19. The dose from an internal radionuclide is generally proportional to the cumulated activity in the source organ. In order to determine the cumulated activity it is necessary to know:
a. The administered activity.
b. Physical half-life.
c. Biological half-life.
d. Organ uptake characteristics.
A.20. Which of the following characteristics (combined) would produce transient
equilibrium?
a. Parent half-life = 6 hours.
b. Daughter half-life = 6 hours.
c. Parent half-life = 67 hours.
d. Daughter half-life = 67 hours.
A.21. The exposure output of an x-ray tube can be changed without changing the spectrum by adjusting the:
a. KV.
b. MAS.
c. Filter.
d. Focal-spot size.
A.22. The energies of characteristic x-radiation are determined by the:
a. KV.
b. MAS.
c. Anode material.
d. Filtration.
A.23. The efficiency of x-ray production (exposure/heat unit) can generally be
increased by increasing the:
a. Focal spot size.
b. KV.
c. MA.
d. Exposure time.
A.24. Constant potential x-ray generators are usually preferred over single-phase generators because they make it possible to use:
a. Smaller focal spots.
b. Shorter exposure times.
c. Less MAS.
d. High speed anode rotation.
A.25. Contemporary x-ray generators often use high-frequency power supplies.
These generators produce:
a. A nearly constant potential.
b. Large, rapid change of KV during exposure.
c. Rapid multiple exposures.
d. High speed anode rotation.
A.26. Design characteristics and operating conditions of an x-ray tube which
will affect the heat capacity of the focal spot area include:
a. KV and MAS.
b. Anode rotation speed.
c. Anode angle.
d. KV waveform.
A.27. The maximum field of view which can be obtained with a specific
radiographic system is generally limited by the:
a. Focal spot size.
b. Anode size.
c. Anode angle.
d. Heel effect.
A.28. The maximum MA which can be used for a single radiographic exposure is
related to the:
a. KV.
b. Exposure time.
c. Focal spot size.
d. Anode rotation speed.
A.29. When a photon engages in a Compton interaction it will:
a. Lose energy.
b. Change speed.
c. Change direction.
d. Ionize the atom.
A.30. The conditions (combined) which would produce a high rate of Compton
interactions compared to photoelectric interactions are:
a. Photon energy = 10 kev.
b. Photon energy = 100 kev.
c. Soft tissue.
d. Bone.
A.31. When a positron engages in an interaction with an electron it:
a. Transfers its energy to the electron.
b. Annihilates the electron.
c. Produces a positive ion.
d. Produces photons.
A.32. A mass attenuation coefficient value for a specific material is affected
by:
a. Material thickness.
b. Material density.
c. X-ray energy.
d. Size of exposed area.
A.33. The primary x-ray beam penetration (percent) through a patient can be
increased by increasing the:
a. KV.
b. MAS.
c. Filtration.
d. Beam area.
A.34. If filtration in an x-ray machine is increased from 3 mm to 4 mm of Al
there will be an increase in:
a. Exposure output (mR/mAs).
b. HVL.
c. Exposure to patient.
d. X-ray beam penetration.
A.35. The HVL of an x-ray beam depends on the:
a. KV.
b. MAS.
c. Filter.
d. Focal-spot size.
A.36. Molybdenum is the most common filter material in mammographic systems. It
is used because it produces:
a. Characteristic radiation.
b. Increased breast penetration.
c. High absorption above the K-edge energy.
d. High absorption below the K-edge energy.
A.37. Relatively low KV values are used in some x-ray procedures for the purpose of:
a. Increasing penetration.
b. Increasing contrast sensitivity.
c. Decreasing patient exposure.
d. Decreasing area contrast.
A.38. Changing the KV from 90 to 70 will generally:
a. Increase calcium-soft tissue contrast.
b. Require an increase in MAS by at least a factor of 2.
c. Increase patient exposure.
d. Improve iodine-soft tissue contrast.
A.39. Changing from a 5:1 ratio to a 10:1 ratio grid will increase:
a. Patient exposure.
b. Image contrast.
c. Required KV or MAS.
d. X-ray tube heating.
A.40. If you changed from a 10:1 ratio grid to a 5:1 grid in a radiographic
procedure you would expect:
a. A decrease in patient exposure.
b. Improved contrast.
c. Decreased blurring.
d. Less grid cut-off.
A.41. If you change from a low ratio to a high ratio grid you would expect:
a. A decrease in patient exposure.
b. An increase in image contrast.
c. An increase in grid x-ray penetration.
d. Positioning to be less critical.
A.42. The radiographic visibility and contrast of a 1 cm soft tissue mass in the
body would generally be decreased by an increase in the:
a. Focal spot size.
b. Field of view.
c. KV.
d. Object-receptor distance.
A.43. If a "medium" speed intensifying screen is replaced with a "high" speed
screen (same phosphor material) for the purpose of reducing patient exposure,
there will be less:
a. Contrast.
b. Visibility of anatomical detail.
c. Quantum noise.
d. Exposure latitude.
A.44. The thickness of an intensifying screen has a significant effect on:
a. Image contrast.
b. Image blurring.
c. Receptor sensitivity.
d. Patient exposure.
A.45. Potential sources of blurring within a radiograph receptor include:
a. Light cross-over within the film.
b. Space between the film and intensifying screen.
c. Spreading of light within the screen.
d. Incorrect spectral matching.
A.46. Under processing (underdevelopment) of radiographic film can result in
increased film:
a. Sensitivity.
b. Contrast.
c. Fog.
d. Density.
A.47. The sensitivity (speed) of a radiographic film used with an intensifying
screen can be affected by:
a. Amount of exposure.
b. Exposure time.
c. Developer concentration.
d. Development temperature.
A.48. The wavelength (color) sensitivity of a radiographic film must be considered when selecting:
a. Developer chemistry.
b. Developer temperature.
c. Intensifying screens.
d. Safelights.
A.49. Compared to normal processing conditions, a general radiographic film
developed at a higher temperature will have increased:
a. Sensitivity (speed).
b. Hypo retention.
c. Base + fog density.
d. Density.
A.50. If a "high" speed radiographic film is substituted for a "medium" speed
film the results would be:
a. Higher contrast.
b. Less visibility of detail because of more blurring.
c. Reduced patient exposure.
d. Increased quantum noise.
A.51. Factors which would be appropriate for conventional chest radiography
are:
a. High contrast film.
b. 0.1 mm focal spot.
c. 120 kV.
d. 10 to 1 ratio grid.
A.52. Conditions which can reduce contrast in a general radiographic image
include:
a. Underexposure.
b. Overexposure.
c. Underdevelopment.
d. Overdevelopment.
A.53. The amount of contrast in a radiograph can be affected by:
a. The latitude of the film.
b. Processing conditions.
c. Amount of exposure.
d. Film-screen contact.
A.54. If the KV for an abdominal radiograph is changed from 80 kV to 90 kV
and the MAS is adjusted to give the same film density:
a. The exposure to the patient will increase.
b. The x-ray tube heating will decrease.
c. The contrast will increase.
d. The quantum noise will decrease.
A.55. Relatively long exposure times are used in some radiographic procedures
(such as mammography). This is necessary in order to use:
a. Smaller focal spots.
b. More compression.
c. Reduced MA and KV values.
d. More sensitive (faster) receptors.
A.56. Potential advantages of using a higher KV (90 rather than 70) in
radiography include:
a. Reduced patient exposure.
b. Reduced x-ray tube heating.
c. Shorter exposure times.
d. Decreased area contrast.
A.57. If a 400 speed radiographic receptor is replaced with a 200 speed
receptor approximately the same film density would be obtained if:
a. The MAS is changed from 100 MAS to 50 MAS.
b. The KV is changed from 50 KV to 100 KV.
c. The focal spot-receptor distance is changed from 72 inches to 40 inches.
d. The film processing temperature is increased as necessary.
A.58. If mammograms from a specific machine are consistently underexposed
possible causes can be:
a. AEC not calibrated for the specific receptor.
b. Density control not set to proper value.
c. Back-up time not set to proper value.
d. Sensor field incorrectly positioned with respect to anatomy.
A.59. Imaging systems are often evaluated by measuring their resolution (line pairs/mm). Resolution is a characteristic which is directly / indirectly related to:
a. Image noise.
b. Image blurring.
c. Image unsharpness.
d. Visibility of anatomical detail.
A.60. Increasing the blurring in a medical imaging system will:
a. Reduce contrast of small objects.
b. Reduce resolution.
c. Reduce noise.
d. Reduce artifacts.
A.61. When a geometric magnification technique is used, as in mammography, it
can:
a. Increase patient exposure.
b. Increase scattered radiation.
c. Decrease blurring of small objects and improve visibility of detail.
d. Require a larger receptor.
A.62. When the smaller focal spot size of an x-ray tube is selected, you
would expect:
a. Reduced scattered radiation.
b. Improved visibility of anatomical detail.
c. Increased image noise.
d. Limited MA.
A.63. When using a magnification technique in radiography it is essential to
have:
a. Low KV.
b. Low MAS.
c. A short exposure time.
d. A small focal spot.
A.64. A small focal spot is used to:
a. Reduce patient exposure.
b. Decrease image noise.
c. Increase visibility of detail.
d. Reduce image blurring.
A.65. The fluoroscopic field of view (mode) is increased from 6 in to 9 in.
There will be an increase in:
a. The patient entrance exposure.
b. The visibility of anatomical detail.
c. The gain of the image intensifier tube.
d. The number of video scan lines.
A.66. While fluoroscoping, the gain of the image intensifier tube can be
increased by increasing the:
a. KV.
b. Density control.
c. Gain control.
d. Field of view (mode).
A.67. Visibility of detail in fluoroscopy can generally be improved by using:
a. Low KV.
b. Small FOV (field of view).
c. Low MA.
d. Low exposure rate.
A.68. The quantum noise in a fluoroscopic image can generally be reduced by
increasing:
a. The KV.
b. The field of view (mode).
c. Focal spot size.
d. Image intensifier tube gain.
A.69. Quantum noise in radiography can generally be decreased by:
a. Using a film with higher sensitivity (speed).
b. Using smaller focal spots.
c. Using high ratio grids.
d. Increasing the aluminum filtration.
A.70. The quantum noise in radiography can generally be decreased without
increasing patient exposure by using:
a. Intensifying screens with a higher absorption efficiency.
b. Intensifying screens with a higher conversion efficiency.
c. Film with a higher sensitivity (speed).
d. Thicker intensifier screens.
A.71. Image noise will generally be increased by:
a. Blurring the image.
b. Increasing image contrast.
c. Averaging several images together.
d. Subtracting one image from another.
A.72. Visibility of detail in a digital image will generally be affected by
changing the:
a. Bits per pixel from 12 to 16.
b. Pixels per image.
c. Matrix size.
d. Field of view.
A.73. The matrix size selected for a digital image will have a significant and
direct effect on:
a. Image contrast.
b. Image detail.
c. Storage requirements.
d. Field of view.
A.74. Changing from a 256 x 256 to a 512 x 512 matrix for a digital image will:
a. Increase image noise.
b. Increase visibility of detail.
c. Increase shades of gray.
d. Double the required disk storage capacity.
A.75. The advantage(s) of using 12 bits rather than 8 bits for a digital image is/are that it provides a:
a. A larger range of pixel values.
b. More shades of gray.
c. Better image detail.
d. Higher image contrast.
A.76. The subtraction of one digital image from another (digital subtraction
angiography) will generally:
a. Improve vascular contrast.
b. Improve visibility of detail (reduce blurring).
c. Decrease image noise.
d. Decrease image artifacts
A.77. A CT number value of 100 for a specific soft tissue indicates that it:
a. Has a higher than normal water content.
b. Probably has a density greater than 1 gm/cc.
c. Will appear bright if a window with a width of 50 is centered at 50.
d. Will change to a value of 50 if the slice thickness is reduced to one half.
A.78. The visibility of anatomical detail in a CT image will increase (blur
will decrease) when:
a. The slice thickness is decreased.
b. The field of view is decreased.
c. The matrix size is decreased.
d. The smoothing filter algorithm is used.
A.79. If a CT viewing window is centered at +100 with a width of 50:
a. Fat will appear black.
b. Water will appear black.
c. Tissue with a CT number of 100 will appear black.
d. Tissue with a CT number of 150 will appear white.
A.80. Changing the CT image matrix size will have a significant effect on:
a. CT number values.
b. Image detail.
c. Image noise
d. Scan time.
A.81. CT image detail (blurring) can be affected by:
a. The size of the focal spot.
b. The size of the detector.
c. The size of a voxel.
d. Type of filter algorithm.
A.82. As an ultrasound pulse moves through tissue in a patient's body it
will undergo a change in:
a. Frequency.
b. Amplitude (energy).
c. Physical size.
d. Intensity.
A.83. In order to estimate the total attenuation of an ultrasound pulse
passing through tissue you would need to know:
a. The size of the pulse.
b. Frequency.
c. Type of tissue.
d. Distance.
A.84. Changing from a 2 MHz to a 5 MHz ultrasound transducer would generally
produce:
a. Faster imaging.
b. Deeper penetration.
c. Shorter wavelengths.
d. Shorter ultrasound pulses.
A.85. The characteristics of tissue through which an ultrasound pulse passes
will have an effect on the pulses:
a. Frequency.
b. Velocity.
c. Wavelength.
d. Amplitude.
A.86. The rate at which an ultrasound pulse is absorbed (attenuated) as it
passes through tissue is affected by:
a. The pulse amplitude.
b. The pulse intensity.
c. The pulse frequency.
d. Characteristics of the tissue.
A.87. You would generally select a high frequency transducer to get:
a. Better tissue penetration.
b. Better image detail.
c. Faster imaging.
d. Decreased attenuation.
A.88. Factors which can have an effect on visibility of anatomical detail
(blurring) in ultrasound image include:
a. Frequency.
b. Transducer focusing.
c. TGC.
c. Pulse rate.
A.89. In ultrasound imaging, increasing the number of scan lines in the
image will generally:
a. Increase imaging depth.
b. Increase visibility of anatomical detail.
c. Limit image rate (images/sec).
d. Increase pulse velocity.
A.90. The type (s) of ultrasound image artifacts produced by a fluid-filled compartment include:
a. Shadowing.
b. Reverberation.
c. Enhancement.
d. Refraction.
A.91. Motion (M) mode ultrasound uses:
a. Continuous wave (CW) Doppler.
b. Pulsed Doppler.
c. Color Doppler.
d. Duplex Doppler.
A.92. When using Doppler ultrasound to determine blood flow velocity it is
necessary for the equipment operator to make a specific adjustment unique to the
Doppler function for:
a. Transducer frequency.
b. Depth of vessel.
c. Direction of vessel.
d. Size of vessel.
A.93. In MRI the resonant frequency of a specific tissue is determined or
affected by the:
a. Specific isotope being imaged.
b. Characteristics of the molecule.
c. Orientation of magnetic field.
d. Strength of the magnetic field.
A.94. The proton resonant frequency of tissue in MRI is determined by:
a. Type of tissue (fat, fluid).
b. Strength of magnetic field.
c. Direction of magnetic field.
d. T1 and T2 values.
A.95. Dephasing of protons within a voxel will be caused by:
a. Strong magnetic fields.
b. Weak magnetic fields.
c. Inhomogeneous fields.
d. Magnetic field gradients
A.96. In comparison to other isotopes, hydrogen-1 is most useful for MRI because of its:
a. High isotopic abundance.
b. High tissue concentration.
c. High NMR sensitivity.
d. High spin density.
A.97. During the magnetic resonance relaxation process after a 90° pulse:
a. Longitudinal magnetization increases.
b. Transverse magnetization increases.
c. Proton density increases.
d. Image contrast is created.
A.98. T1 and T2 values depend on:
a. Voxel size.
b. Direction of magnetic field.
c. Type of tissue.
d. Molecular size.
A.99. Tissue characteristics which can produce a relative and increased
intensity (brightness) contrast in a magnetic resonance image include:
a. Short T1 values.
b. Long T1 values.
c. Short T2 values.
d. Long T2 values.
A.100. An air gap technique will generally improve image contrast because:
a. It is used with a small focal spot.
b. The air absorbs scattered radiation.
c. It is used with a small field of view.
d. The scatter is more diverging than the primary beam.
A.101. The inversion recovery (IR) method can be used rather than the conventional spin echo method to produce:
a. More T1 contrast.
b. More T2 contrast.
c. Faster acquisition.
d. Fat suppression.
A.102. In MRI, magnetic field gradients are used for:
a. Slice selection.
b. Frequency encoding.
c. Phase encoding.
d. Gradient echo imaging.
A.103. The advantage(s) of 3D volume acquisition compared to 2D multi-slice
acquisition in MRI is/are:
a. Faster image reconstruction.
b. Thinner slices.
c. Reduced motion artifacts.
d. Produces a large image matrix.
A.104. Factors which will have an effect on the amount of noise appearing in
a magnetic resonance image include:
a. TR and TE.
b. Field of view.
c. Matrix size.
d. Slice thickness.
A.105. The process of averaging is used in MRI for the purpose of:
a. Reducing acquisition time.
b. Reducing image noise.
c. Improving detail.
d. Combining T1 and T2 contrast.
A.106. The amount of time necessary to acquire an MR image depends on:
a. TR.
b. TE.
c. Field of view.
d. Matrix size.
A.107. (A) Desirable characteristic(s) of surface coils in MRI is/are that
they produce:
a. Better image detail.
b. Less noise.
c. More intense signals.
d. Thinner slices.
A.108. Flow related enhancement (bright blood) in spin echo imaging is
generally associated with:
a. Slow flow.
b. Fast flow.
c. Turbulent flow.
d. Laminar flow.
A.109. In MRI angiography the advantage(s) of a 2D slice acquisition
(selective excitation) compared to a 3D volume acquisition is/are:
a. Improved vessel detail.
b. Reduced saturation effects.
c. Better for low velocity flow.
d. Better for small vessels.
A.110. The technique of saturation (pre-saturation) is used in MRI for the purpose(s) of:
a. Reducing motion artifacts.
b. Reducing blood flow induced artifacts.
c. Reducing fold-over artifacts.
d. Reducing chemical-shift artifacts.
A.111. If a low-energy collimator is (incorrectly) used with a high-energy radionuclide the results would be:
a. A reduced camera sensitivity (counting efficiency).
b. A blurred image.
c. A reduced field of view.
d. Reduced image detail.
A.112. Compared to a diverging collimator, a converging collimator will
produce:
a. A increase in sensitivity when distance is increased.
b. Better image detail.
c. A reduced FOV as distance is increased.
d. Smaller images on the display.
A.113. If the PHA window on a gamma camera is (incorrectly) set below the
photopeak energy you would expect to get:
a. A decreased field of view.
b. Decreased sensitivity.
c. An image of primarily scattered radiation.
d. Decreased lesion contrast.
A.114. The sensitivity of a gamma camera can be affected by the:
a. Counting time.
b. Type of collimator.
c. PHA window level.
d. PHA window width.
A.115. A flood source can be used to check a gamma camera's:
a. Maximum count rate.
b. Collimator focusing.
c. Uniformity.
d. Spatial distortion.
A.116. SPECT is more technically demanding than planar imaging. Which of
the following create artifacts in the tomographic images?
a. Patient motion during imaging.
b. Misalignment of the center of rotation (with the detector axis).
c. Ring artifacts due to defects in the collimator.
d. Scattered radiation.
A.117. The surface entrance exposure to a patient in a radiographic procedure can be changed by changing the:
a. KV.
b. Focal spot size.
c. Grid ratio.
d. Receptor sensitivity.
A.118. In order to determine the dose to a patient from an internal
radionuclide using the standard MIRD method you would need to know:
a. The name of the radionuclide.
b. The effective half-life.
c. The administered activity.
d. The size of the target organ.
A.119. In order to determine the effective dose received by a
radiologist while performing an x-ray procedure, it would be necessary to know
the:
a. X-ray beam spectrum.
b. Absorbed dose in the specific tissues and organs.
c. Radiation weighting factors. (f)
d. Tissue weighting factors.
A.120. According to current guidelines (NCRP) a whole body equivalent dose
of 5 rem per year for a radiation worker is considered:
a. Safe.
b. Acceptable.
c. ALARA.
d. Threshold.
A.121. Identify which of the following factors, if changed, might require a
reevaluation of the wall shielding in an x-ray room.
a. Type of procedure.
b. Number of patients per day.
c. Direction of x-ray beam.
d. Type of activity in adjacent areas.
A.122. In order to calculate the exposure rate that a visitor might
receive from a patient with a therapeutic dose of a radionuclide you would need
to know the:
a. Name of the nuclide.
b. Activity.
c. Exposure time.
d. Distance.
A.123. In a crystal scintillation detector the size or amplitude of the electrical pulse is generally proportional to the:
a. Activity.
b. Gamma photon energy.
c. Number of gamma photons.
d. Number of light photons
Single Choice Questions
B.1. The order of imaging methods (from worst to best) with respect to visibility of detail (resolution) is:
a. Gamma camera, fluoroscopy, CT.
b. Ultrasound, fluoroscopy, radiography.
c. Gamma camera, fluoroscopy, MRI.
d. Radiography, fluoroscopy, MRI.
B.2. In the radiology literature the relationship between the sensitivity and
specificity of a diagnostic procedure is generally shown using a:
a. MTF curve.
b. ROC curve.
c. True-positive/false-positive ratio.
d. True-negative/false-negative ratio
B.3. Intensity is a quantity used in several areas of radiology. It
expresses:
a. Total energy.
b. Total power.
c. Total energy per unit area.
d. Power per unit area.
B.4. The radiofrequency energy used in MRI and x-radiation have essentially
the same:
a. Velocity.
b. Photon energy.
c. Wavelength.
d. Frequency.
B.5. A viewbox for mammographic films should have a brightness of
approximately:
a. 3.5 foot-candles.
b. 3.5 lumens.
c. 3500 luxes.
d. 3500 nits.
B.6. The exposure rate from scattered radiation at a distance of 3 meters
from a patient undergoing a fluoroscopic exam would be approximately:
a. 1/3 mR/min.
b. 1 mR/min.
c. 3 mR/min.
d. 9 mR/min.
B.7. The time required for the activity of a radioactive sample to decay to
10% is between:
a. 1 and 2 half-lives.
b. 2 and 3 half-lives.
c. 3 and 4 half-lives.
d. 4 and 5 half-lives.
B.8. When the half-life of a daughter product (1 day) is approximately 10% of
the half-life of the parent material (10 days), you would expect to get:
a. No equilibrium.
b. Transient equilibrium.
c. Secular equilibrium.
d. Metastable equilibrium.
B.9. The decay constant for 182Ta is 0.006 day-1. What
is its half life?
a. 167 days.
b. 115 days.
c. 0.0087 days.
d. 0.006 days.
e. 83 days.
B.10. A rule of thumb often used says a radioisotope may be treated as
"non-radioactive" at the end of 10 half-lives. What fraction of the radioisotope
actually remains at this time?
a. 1 - (1/2)10
b. 1 - e-0.693 x 10
c. (1/2)10
d. e-0.693 x 10
B.11. The heat capacity of the anode body is a significant limiting factor
in:
a. Magnification mammography.
b. Chest radiography.
c. Computed tomography.
d. All high KV techniques.
B.12. The most favorable condition for the photoelectric interaction is when
the photon energy is _____ the electron binding energy:
a. Much less than.
b. A little less than.
c. Much greater than.
d. A little greater than.
B.13. If an x-ray beam has a HVL of 3.5 mm of Al, the penetration through 8
mm of Al will be approximately:
a. 40%.
b. 30%.
c. 20%.
d. 10%.
B.14. The appropriate test to determine if an x-ray machine has adequate
filtration is to measure the:
a. Exposure output (mR/mAs).
b. HVL.
c. KV.
d. Patient exposure.
B.15. The x-ray photon energy range which will be most appropriate and
produce the best contrast with iodine is:
a. 25 keV - 30 keV.
b. 30 keV - 33 keV.
c. 33 keV - 40 keV.
d. 60 keV - 70 keV.
B.16. For vascular imaging with iodine contrast media you would expect to get the best contrast by using:
a. 35 kV.
b. 65 kV.
c. 95 kV.
d. 125 kV.
B.17. For routine chest radiography you would expect to get the best contrast
characteristics by using:
a. 35 kV.
b. 65 kV.
c. 95 kV.
d. 125 kV.
B.18. The fraction (percent) of viewbox light that will pass through a film
which has a density of 2.5 is:
a. 3%.
b. 1%.
c. 0.3%.
d. 0.1%.
B.19. If a radiographic procedure requires 20 mAs for a focal
spot-to-receptor distance (FRD) of 40 in., a FRD of 80 in. would require:
a. 5 mAs.
b. 10 mAs.
c. 40 mAs.
d. 80 mAs.
B.20. The primary factor that limits the maximum MA that can be used during a
radiographic exposure is:
a. Anode angle.
b. Focal spot size.
c. Cathode temperature.
d. Exposure time.
B.21. The spatial resolution of an imaging system is most directly related to:
a. Visibility of large low contrast objects.
b. Visibility of noisy images.
c. Visibility of soft tissues.
d. Visibility of anatomical detail.
B.22. In a conventional fluoroscopic system images are created and displayed
at a rate of:
a. 30 per second.
b. 120 per second.
c. 525 per second.
d. 1,024 per second.
B.23. The subtraction of one digital image from another (digital subtraction angiography) will generally:
a. Improve vascular contrast.
b. Improve visibility of detail (reduce blurring).
c. Decrease image noise.
d. Decrease image artifacts.
B.24. A 1024 x 1024 eight-bit image will require a storage capacity of:
a. 1 megabyte.
b. 4 megabytes.
c. 16 megabytes.
d. 64 megabytes.
B.25. The value of a CT number (in Hounsfield units) is determined primarily by:
a. Matrix size.
b. Slice thickness.
c. KV.
d. Tissue density.
B.26. The parameters spatial-peak, temporal-average, and pulse-average must
be considered when expressing values for ultrasound:
a. Intensity.
b. Absorption.
c. Velocity.
d. Pulse rate.
B.27. The lowest rate of ultrasound absorption occurs in:
a. Fat.
b. Air.
c. Bone.
d. Lung.
B.28. The principal advantage of an annular-array transducer is that it
provides:
a. Faster imaging.
b. Better penetration.
c. Variable frequency.
d. Variable focal depth.
B.29. While doing an ultrasound scan you notice that the echoes at a depth
of 4 - 6 cm appear relatively weak. The appropriate action to increase their
brightness in the image would be to adjust the:
a. Frequency.
b. Focusing.
c. TGC.
d. Beam intensity.
B.30. The effects of tissue absorption are compensated for in an ultrasound
image by using:
a. Dynamic focus.
b. Time-gain compensation.
c. Low-frequency transducers.
d. Phased-array transducers.
B.31. One or more ghost-images of a body structure displayed at different
depths within an ultrasound image are signs of:
a. Shadowing.
b. Reverberation.
c. Refraction.
d. Enhancement.
B.32. Which of the following factors would be most appropriate to produce a T1-weighted image:
a. TR = 2,000, TE = 20.
b. TR = 2,000, TE = 100.
c. TR = 500, TE = 20.
d. TR = 500, TE = 100.
B.33. When using a 2D multi-slice acquisition in MRI, the principal factor
which limits the number of slices in one acquisition package is:
a. Slice thickness.
b. Matrix size.
c. TR.
d. TE.
B.34. The factor which has the most significant effect on the amount of
chemical-shift artifact in MRI is the:
a. Matrix size.
b. Phase encoding direction.
c. Magnetic field strength.
d. Gradient strength.
B.35. Of the following radiations, which would be the most desirable for
radionuclide imaging:
a. 15 keV gamma.
b. 150 keV gamma.
c. 150 keV beta.
d. 1500 keV gamma.
B.36. The full width at half maximum (FWHM) of a photopeak is a measure of:
a. PHA window setting.
b. Camera sensitivity.
c. Field of view.
d. Detector energy resolution.
B.37. Which of the following statements best describes the primary purpose of a collimator on a gamma camera:
a. It prevents scattered photons from reaching the detector.
b. It prevents cosmic radiation from reaching the detector.
c. It stops pre-detector scattered photons.
d. To allow photons from a given region of interest to strike the detector and try to minimize the contribution of photons originating from outside this region.
B.38. The principal disadvantage in using a high resolution collimator on a
gamma camera is that it has:
a. Limited field of view.
b. More distortion.
c. Less scatter rejection.
d. Lower sensitivity.
B.39. Which one of the following is not characteristic of PET:
a. Lead collimators.
b. Positron emitters.
c. 511 keV photons.
d. Absolute attenuation correction.
B.40. If a measurement of radioactivity has a one standard deviation error of 10% at the 68% confidence level, the error would be _____ at the 95% confidence level.
a. 2.5%.
b. 5%.
c. 20%.
d. 30%.
B.41. When counting a radioactive sample to determine its activity the
statistical error in the measurement can generally be controlled by giving
attention to:
a. Counting geometry.
b. Counting time.
c. Background radiation.
d. Confidence level.
B.42. Assume that a background count is subtracted from the measured count
of a radio-active sample. The expected error in the difference will be:
a. Equal to the error for the measured counts.
b. Equal to the error for the background counts.
c. Less than the error for either measured or background.
d. More than the error for each the measured and background.
B.43. Which one of the following would be a typical surface entrance
exposure rate during fluoroscopy:
a. 0.5 R/min.
b. 3 R/min.
c. 10 R/min.
d. 20 R/min.
B.44. Which of the following would be a reasonable mean glandular dose for a
single view in mammography:
a. 12 mrad.
b. 24 mrad.
c. 120 mrad.
d. 300 mrad
B.45. The most appropriate instrument for measuring the scattered x-ray
exposure from a patient is a:
a. Geiger counter.
b. Large ionization chamber.
c. Small ionization chamber.
d. Scintillation detector.
Matching Questions
For the following task, select the most appropriate device from the list
below.
C.1. Measure the activity of a 1 mCi sample.
C.2. Measure the activity of a 0.1 uCi sample.
C.3. Locate spilled radioactivity.
C.4. Measure scattered X-radiation from a patient.
C.5. Measure the exposure output from a fluoroscope.
C.6. Measure gamma photon energies.
C.7. Monitor exposure to a fetus.
A. Small ionization chamber
B. Large ionization chamber
C. Scintillation well counter
D. Dose (activity) calibrator
E. Geiger counter
F. TLD
G. PHA
Select the factor(s) from the list below that will have an effect on the
following characteristic of an X-ray beam:
C.8. Exposure output (mR/mAs).
C.9. Minimum photon energy.
C.10. Maximum photon energy.
C.11. Effective energy.
C.12. HVL.
C.13. Ratio of characteristic to bremmstrahlung.
C.14. Penetration
A. KVP
B. MA
C. Exposure time
D. Anode material
E. Filtration
F. KV waveform
.
Select the MRI parameters(s) from the list below which, when changed, will have an effect on:
C.15. Acquisition time for one set of 2D multislice images.
C.16. Acquisition time for one set of 3D volume acquisition images.
C.17. T1 contrast with gradient echo imaging.
C.18. Signal intensity from 5 mm3 voxel with spin echo imaging.
C.19. T2 contrast with spin echo imaging.
C.20. Suppression of signals from fat.
C.21. Direction of motion-induced artifacts.
C.22. Voxel size.
A. TR
B. TE
C. TI
D. Flip angle
E. Slice thickness
F. Field of view
G. Matrix size in phase encoded direction
H. Matrix size in frequency encoded direction
I. Number of signals averaged
J. Number of slices
K. Type of RF coil
L. Phase encoded direction
Select the factor(s) from the list below which, when changed, will have an
effect on:
C.23. Gamma camera sensitivity.
C.24. Image detail (resolution).
C.25. Image noise (for fixed sensitivity).
C.26. Elimination of scattered radiation from image.
C.27. Dose to the patient.
C.28. Field of view.
C.29. Image magnification.
A. Radionuclide
B. Administered activity
C. Half life
D. Imaging time
E. Type of collimator
F. Patient-collimator distance
G. PHA window level
H. PHA window width
Select the factor(s) from the list below which can be used to measure:
C.30. Dose to the glandular tissue in mammography.
C.31. Rate at which heat is produced in an x-ray tube.
C.32. Total radiation energy imparted to the patient.
C.33. Intensity of an ultrasound beam.
C.34. Equivalent dose.
C.35. Activity administered to a patient.
C.36. Surface exposure to a patient.
A. roentgen
B. rad
C. rem
D. gray
E. sievert
F. coulomb/kg of air
G. curie
H. becquerel
I. roentgen-cm2
J. joules
K. watts
L. watts/cm2
M. heat units