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CT Registry Review Questions

91 Questions
Computed Tomography Quizzes & Trivia

Question for Computed Tomography Registry

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Questions and Answers
  • 1. 
    • A. 

      IV contrast material is better visualized

    • B. 

      Streak artifacts are reduced or eliminated.

    • C. 

      The patient is more comfortable during scanning.

    • D. 

      The patient receives a lower radiation dose

  • 2. 
    Which two strategies can reduce the effect of dental fillings in a sinus study?
    • A. 

      High mA and shcrt scan time

    • B. 

      Low kVp and high contrast, or bone alogrithm

    • C. 

      Adjust the angle of the gantry and widen the window width

    • D. 

      Small focal spot and small display field

  • 3. 
    Which of the following conditions may be visualized in a CT study of the brain?
    • A. 

      Glioblastoma

    • B. 

      Wilm's Tumor

    • C. 

      Krukenberg Tumor

    • D. 

      Plasmacytosis

  • 4. 
    Which of the following is affected by teh slice spacing in a CT study?
    • A. 

      Spatial Resolution

    • B. 

      Quantum Mottle

    • C. 

      Radiation Dose to the Patient

    • D. 

      Signal-to-Noise Ration

  • 5. 
    What is the name of the pinecon-shaped structure of the brain the can often be seen as calcified in CT images?
    • A. 

      Choroid Plexus

    • B. 

      Pineal Gland

    • C. 

      Caudate Nucleus

    • D. 

      Middle cerebral Artery

  • 6. 
    Third generation (rotate/rotate) scanners overcame which of the following limitations?
    • A. 

      Detector singal drift sensitivity

    • B. 

      Translation motion

    • C. 

      Spurious signals from moving signal wires

    • D. 

      Cost

  • 7. 
    What helical or spiral computed tomography term is defined as the table increment in distance per mm per 360 degrees gantry rotation divided by the section thickness in mm?
    • A. 

      Rotation

    • B. 

      Spiral

    • C. 

      Helix

    • D. 

      Pitch

  • 8. 
    What determines the section thickness?
    • A. 

      Scan arc

    • B. 

      Filtration algorithm

    • C. 

      Incident beam collimation

    • D. 

      Detector alignment

  • 9. 
    What effect would an array processor failure have on image processing?
    • A. 

      Increase image display time

    • B. 

      Halt analog to digital conversions

    • C. 

      Lengthens detector data acquisition time

    • D. 

      Decrease xray tube output

  • 10. 
    What change will occur in the number of detected photons if a section thickness is changed from 5 mm to 10mm?
    • A. 

      Decrease 50%

    • B. 

      Decrease 25%

    • C. 

      Increase 50%

    • D. 

      Increase 100%

  • 11. 
    Which of the following will magnify the image?
    • A. 

      Increase field of view

    • B. 

      Decreasing field of view

    • C. 

      Increasing section thickness

    • D. 

      Decreasing section thickness

  • 12. 
    Which of the following is convolution?
    • A. 

      Filtered back projection

    • B. 

      Fourier transform

    • C. 

      Iterative filtration

    • D. 

      3-d rendering

  • 13. 
    Which of the following determines the maximum number of shades of gray that can be displayed on the CT monitors?
    • A. 

      Window level

    • B. 

      Window width

    • C. 

      Pixel size

    • D. 

      Matrix size

  • 14. 
    Which of the following are benefits of narrower section thicknesses?
    • A. 

      Reduced partial volume averaging and improved spatial resolution

    • B. 

      Decreased scan time, and more anatomy covered

  • 15. 
    Which of the following is the term used to describe a voxel value that is the average of multiple tissue types contained within the voxel?
    • A. 

      Linear attenuation coefficient

    • B. 

      Partial volume averaging

    • C. 

      Low contrast resolution

    • D. 

      Edge gradient averaging

  • 16. 
    • A. 

      Ct numbers above +300

    • B. 

      Ct numbers between +150 and +300

    • C. 

      Ct numbers between +150 and -150

    • D. 

      Ct numbers below -150

  • 17. 
    Which fo the following is the central value in a range of gray shades used to display the image?
    • A. 

      Window width

    • B. 

      Window level

    • C. 

      Region of interest

    • D. 

      Dose index

  • 18. 
    What is the most common type of film used to recore CT exams?
    • A. 

      Single emulsion

    • B. 

      Double emulsion

    • C. 

      Triple emulsion

    • D. 

      Rare earth

  • 19. 
    Which of the following increase signal to noise ration?
    • A. 

      Increased mAs

    • B. 

      Wider section thickness

    • C. 

      Increased detection efficiency

  • 20. 
    What is the appropriate compensation to avoid quantum noise when performing thin section computed tomography?
    • A. 

      Increase mAs

    • B. 

      Decrease field of view

    • C. 

      Increase matrix size

    • D. 

      Decrease scan speed

  • 21. 
    Which describes the relationship between section thickness and noise?
    • A. 

      If section thickness increases, noise increases

    • B. 

      If section thickness increases, noise decreases

    • C. 

      If section thickness decreases, noise decreases

    • D. 

      If section thickness decreases, noise remains unchanged

  • 22. 
    What term is used to describe as the ability to display an image of a large object that is only slightly different in density from its surroundings?
    • A. 

      Spatial resolution

    • B. 

      Contrast resolution

    • C. 

      Linearity

    • D. 

      Clarity

  • 23. 
    Which of the following should be viewed with relatively wide window widths?
    • A. 

      Lung and inner ear

    • B. 

      Lung and brain

    • C. 

      Inner ear and brain

  • 24. 
    How often should an average CT number water calibration test be performed?
    • A. 

      Daily

    • B. 

      Monthly

    • C. 

      Yearly

    • D. 

      Weekly

  • 25. 
    Which of the following accurately describes the relationship between patient dose and pitch?
    • A. 

      If pitch increases, patient dose increases

    • B. 

      If pitch increases, patient dose decreases

    • C. 

      If pitch decreases, patient dose decreases

    • D. 

      If pitch decreases, patient dose remains unchanged

  • 26. 
    Which of the following is defined as the ability to distinguish details in objects of different densities a small distance apart?
    • A. 

      Contrast resolution

    • B. 

      Cross field uniformity

    • C. 

      Spatial resolution

    • D. 

      Interpolation

  • 27. 
    What is the term that is used to describe contrast resolution?
    • A. 

      High spatial detectibilty

    • B. 

      Low spatial detectibilty

    • C. 

      High contrast detectibilty

    • D. 

      Low contrast detectibilty

  • 28. 
    What is the primary type of interaction that contributes to the subject contrast in CT images?
    • A. 

      Pair production

    • B. 

      Photoelectric effect

    • C. 

      Compton scattering

    • D. 

      Linear attenuation

  • 29. 
    What type of scan geometry is responsible for producing ring artifacts?
    • A. 

      Translate-rotate

    • B. 

      Rotate-rotate

    • C. 

      Rotate only

    • D. 

      Helical / spiral

  • 30. 
    • A. 

      The computer overcorrects for beam hardening

    • B. 

      The beam encounters metal in the body

    • C. 

      The body hardens the beam thus lowering the attenuation numbers in the center

    • D. 

      The body hardens the beam thus increasing the attenuation numbers in the center

  • 31. 
    Which of the following can be described as bands and streaks that appear across an area due to bone and soft tissue attenuation values in the same pixel?
    • A. 

      Tube arcing artifacts

    • B. 

      Beam hardening artifacts

    • C. 

      Partial volume artifacts

    • D. 

      Full volume artifacts

  • 32. 
    Which of the following is a streak artifact oriented tangentially to a flat surface having a high spatial frequency?
    • A. 

      Low contrast artifact

    • B. 

      Edge gradient artifact

    • C. 

      Equipment induced artifact

    • D. 

      Signal artifact

  • 33. 
    What filter selection would provide the best detail for imaging of the internal auditory canals?
    • A. 

      Smooth

    • B. 

      Sharp

    • C. 

      Standard

    • D. 

      Soft

  • 34. 
    What anatomical structure forms a roof over the posterior cranial fossa and is shaped like a tent?
    • A. 

      Tentorium cerebelli

    • B. 

      Falx cerebri

    • C. 

      Pontine cistern

    • D. 

      Pia mater

  • 35. 
    What type of artifact generally appears as a dark horizontal line through the petrous ridges?
    • A. 

  • 36. 
    Which of following results from a fracture in the temporal region of the skull with associated tearing of the middle meningeal artery?
    • A. 

      Subdural hematoma

    • B. 

      Epidural hematoma

    • C. 

      Arteriovenous malformation

    • D. 

      Subarchnoid hematoma

  • 37. 
    What canal allows communication between the third and fourth ventricles of the brain?
    • A. 

  • 38. 
    Where is contrast media introduced for a myelography exam of the spinal canal?
    • A. 

      Subdural space

    • B. 

      Epidural space

    • C. 

      Subarachnoid space

    • D. 

      Spinal cord

  • 39. 
    Which of the following would be visualized first when coronal images are obtained via multiplanar reformation from posterior to anterior?
    • A. 

  • 40. 
    Which of the following anatomical structures would be visualized first when obtaining sagittal sections from right to left?
    • A. 

      C-loop of the duodenum

    • B. 

      Tail of the pancreas

    • C. 

      Gallbladder

    • D. 

      Right kidney

  • 41. 
    What type of drug is Demerol?
    • A. 

      Analgesic

    • B. 

      Antipyretic

    • C. 

      Antianxiety agent

    • D. 

      Local anesthetic

  • 42. 
    Which of the following describes rapid, irregular, ineffective twitches of the ventricles?
    • A. 

      Ventricular regurgitation

    • B. 

      Ventricular palpitations

    • C. 

      Ventricular arrythmia

    • D. 

      Ventricular fibrillation

  • 43. 
    Which of the following is the more toxic cation that is incorporated into the organic ionic contrast media?
    • A. 

      Sodium

    • B. 

      Meglumine

    • C. 

      Iodine

    • D. 

      Calcium

  • 44. 
    What term is used to describe the computed tomography appearance of an intracerebral hemorrhage as a result of a higher CT number of the hemorrhage as compared to normal brain tissue?
    • A. 

      Hyperdense

    • B. 

      Isodense

    • C. 

      Hypodense

    • D. 

      Mass effect

  • 45. 
    Which of the following provides optimal liver lesion detection following the introduction of contras media?
    • A. 

      Scanning prior to the equilibrium phase

    • B. 

      Scanning during to the equilibrium phase

    • C. 

      Scanning after to the equilibrium phase

  • 46. 
    Which of the following is the recommended percentage of barium in a barium sulfate suspension utilized in abdominal computed tomography?
    • A. 

      1-3%

    • B. 

      10-20%

    • C. 

      30%

    • D. 

      50%

  • 47. 
    Which of the following are used in scintillation CT detectors?
    • A. 

      Gadolinium based ceramic

    • B. 

      Bismuth germanate

    • C. 

      Calcium fluoride

  • 48. 
    Which of the following will have an effect on image quality?
    • A. 

      Spatial resolution

    • B. 

      Contrast resolution

    • C. 

      Noise

  • 49. 
    What are the primary advantages of narrower section thicknesses?
    • A. 

      Improved spatial resolution

    • B. 

      Reduced partial volume averaging

    • C. 

      Higher contrast

  • 50. 
    Which of the following geometric factors will have an effect on spatial resolution?
    • A. 

      Focal spot size

    • B. 

      Detector aperture width

    • C. 

      Noise

  • 51. 
    What term describes an artifact that may appear on a low dynamic range detector system near the shoulders and hips because dense bone has too severely attenuated the xray beam?
    • A. 

      Beam hardening

    • B. 

      Photon starvation

    • C. 

      Ring

    • D. 

      Partial volume

  • 52. 
    Which of the following will help to reduce partial volume artifacts?
    • A. 

      Scanning thinner sections

    • B. 

      Scanning thicker sections

    • C. 

      Scanning using a higher technique

    • D. 

      Scanning using a lower technique

  • 53. 
    Which of the following terms defines the increase in the mean energy of a polychromatic beam as it passes through an object?
    • A. 

      Partial volume effect

    • B. 

      Beam hardening

    • C. 

      Cross-field uniformity

    • D. 

      Linearity

  • 54. 
    Contrast materials that dissociate into charged particles when placed into solution are termed
    • A. 

      Positive

    • B. 

      Non-ionic

    • C. 

      Ionic

    • D. 

      Negative

  • 55. 
    Which of the following is the correct order for the stages of infection?
    • A. 

      Incubation, prodomal, active, convalescence

    • B. 

      Convalescence, active, prodomal, incubation

    • C. 

      Prodomal, incubation, convalescence, active

    • D. 

      Incubation, convalescence, prodomal, active

  • 56. 
    The term used to descibe the ability of a fluid to flow is
    • A. 

      Density

    • B. 

      Viscosity

    • C. 

      Osmolality

    • D. 

      Specific gravity

  • 57. 
    A patient has a severe vagal reaction to iodinated contrast material that includes bradycardia.  Initial treatment may include
    • A. 

      Atropine

    • B. 

      Diazapam

    • C. 

      Rantidine hyrochloride (Zantac)

    • D. 

      Albuterol sulfate (Proventil)

  • 58. 
    Which of the following interactions between xray and matter results in the largest amount of occupational exposure?
    • A. 

      Characteristic effect

    • B. 

      Compton effect

    • C. 

      Bremsstrahlung effect

    • D. 

      Photoelectric effect

  • 59. 
    The abdominal aorta bifurcates at the level of
    • A. 

      T10

    • B. 

      T12

    • C. 

      L2

    • D. 

      L4

  • 60. 
    After the injection of intravenous contrast material during a CT examination of the brain, which of the following anatomic areas does not enhance?
    • A. 

      Anterior communicating artery

    • B. 

      Choroid plexus

    • C. 

      Posterior horn of the lateral ventricle

    • D. 

      Dura mater

  • 61. 
    The mathematical technique that involves the estimation of an unknown value from values on either side of it its known as
    • A. 

      Filtering

    • B. 

      Interpolation

    • C. 

      Convolution

    • D. 

      Summation

  • 62. 
    When compared with conventional radiography, CT produces diagnostic images with improved
    • A. 

      Low-contrast resolution

    • B. 

      Spatial resolution

    • C. 

      Minute detail

    • D. 

      Patient dose reduction

  • 63. 
    Which of the following is not commonly used as a CT scintillation detector material?
    • A. 

      Ceramic rare earth

    • B. 

      Silver halide

    • C. 

      Bismuth germinate

    • D. 

      Cadmium tungstate

  • 64. 
    Which of the following is the primary interaction between xray photons and tissue during CT examinations?
    • A. 

      Bremsstrahlung effect

    • B. 

      Characteristic effect

    • C. 

      Compton effect

    • D. 

      Coherent scatter

  • 65. 
    Areas of a CT image that contain minimal changes in tissue density are electronically represented by 
    • A. 

      Positive CT numbers

    • B. 

      High spatial frequencies

    • C. 

      Negative CT numbers

    • D. 

      Low spatial frequencies

  • 66. 
    Which of the following reconstruction methods is used by most modern CT scanners?
    • A. 

      Back-projection

    • B. 

      Iterative methods

    • C. 

      Fourier tranform

    • D. 

      Filtered back-projection

  • 67. 
    Which of the following increases the signal-to-noise ratio of a CT image?
    • A. 

      Decreased aperature size

    • B. 

      Decreased mAs

    • C. 

      Increased filtration

    • D. 

      Increased aperature size

  • 68. 
    Statistical noise appears as ___ on a CT image
    • A. 

      Decreased contrast

    • B. 

      Increased brightness

    • C. 

      Concentric circles

    • D. 

      Graininess

  • 69. 
    The term ___ describes the ability of a CT scanner to differentiate objects with minimal differences in attenuation coefficients
    • A. 

      Spatial resolution

    • B. 

      Contrast resolution

    • C. 

      Linearity

    • D. 

      Modulation

  • 70. 
    Which of the following types of contrast material may be used during a CT examination of the chest?
    • A. 

      Diatrizoate meglumine

    • B. 

      Barium sulfate

    • C. 

      Iopamidol

    • D. 

      All the above

  • 71. 
    The kidneys are located in the retroperitoneum and are bound by a band of fibrous connective tissue called
    • A. 

      Cooper's liagment

    • B. 

      Fascia of Cooper

    • C. 

      Linea alba

    • D. 

      Gerota's fascia

  • 72. 
    Which of the following algorithm types provides the greatest soft-tissue detail during a CT study of the pelvis?
    • A. 

      High spatial frequency

    • B. 

      Detail

    • C. 

      Edge

    • D. 

      Low spatial frequency

  • 73. 
    First-generation CT scanners possess which of the following characteristics?
    • A. 

  • 74. 
    The average CT value for blood is approximately
    • A. 

      -50 HU

    • B. 

      0 HU

    • C. 

      +45 HU

    • D. 

      +100 HU

  • 75. 
    Before a CT image can be reconstructed by a computer, the transmission signal produced by the detectors must be converted into numeric information by a(n)
    • A. 

      Kernel

    • B. 

      Analog-to-digital converter

    • C. 

      Array processor

    • D. 

      Digital-to-analog converter

  • 76. 
    The dimensions of a voxel may be calculated as the product of which of the following?
    • A. 

      Matrix size and pixel size

    • B. 

      Pixel size and section width

    • C. 

      DFOV and matrix size

    • D. 

      DFOV and pixel size

  • 77. 
    Which of the following terms are commonly used to describe the ability of a CT scanner to differentiate objects with similar linear attenuation coefficients?
    • A. 

      Spatial resolution

    • B. 

      Contrast resolution

    • C. 

      Spatial resolution and sensitivity

    • D. 

      Sensitivity and contrast resolution

  • 78. 
    Which of the following section widths would cause the greatest amount of partial volume averaging?
    • A. 

      1mm

    • B. 

      3mm

    • C. 

      5mm

    • D. 

      10mm

  • 79. 
    Which of the following has no measurable effect on spatial resolution?
    • A. 

      Focal spot size

    • B. 

      KVp

    • C. 

      Detector sampling frequency

    • D. 

      Matrix size

  • 80. 
    An image that is reconstructed a second time with some change in technical factor is termed _____.
    • A. 

      Reiterated

    • B. 

      Post-processed

    • C. 

      Retrospective

    • D. 

      Reformatted

  • 81. 
    During CT angiography, images may be reconstructed using only the greastest density encountered along each ray.  This type of specialized CT image is called a(n)
    • A. 

      3 demensional model

    • B. 

      Volume-rendered model

    • C. 

      MIP image

    • D. 

      Surface-rendered image

  • 82. 
    The ability of a CT scanner to image a small high-density object is controlled by ___ of the scanner
    • A. 

      Contrast resolution

    • B. 

      Spatial resolution

    • C. 

      Sensitivity

    • D. 

      Contrast resolution and sensitivity

  • 83. 
    Which of the following technical changes may increase the partial volume effect present on a spiral CT scan?
    • A. 

      Decrease the pitch

    • B. 

      Decrease the aperature size

    • C. 

      Increase in matrix size

    • D. 

      Increase in pitch

  • 84. 
    The matrix size describes which of the following?
    • A. 

      Aperture size used during data acquistion

    • B. 

      Number of pixels used to display an image

    • C. 

      Relationship between the field of view and algorithm

  • 85. 
    The type of filter used at the xray tube of a CT scanner is called a
    • A. 

      Kernel

    • B. 

      Water bath

    • C. 

      Bow-tie filter

    • D. 

      Wedge filter

  • 86. 
    Which of the following would increase the noise of a CT image?
    • A. 

      Increased mAs

    • B. 

      Decreased aperture size

    • C. 

      Decreased filtration

    • D. 

      Decreased matrix size

  • 87. 
    The interaction between xray and matter that is responsible for the production of the scatter radiation absorbed by the patient and detectors is
    • A. 

      Compton interaction

    • B. 

      Bremsstrahlung interaction

    • C. 

      Photoelectric effect

    • D. 

      Characteristic interaction

  • 88. 
    The major disadvantage of the back-projection method of image reconstruction is the appearance of the
    • A. 

      Partial volume effect

    • B. 

      Ring artifact

    • C. 

      Gibbs phenomenon

    • D. 

      Star artifact

  • 89. 
    The contast resolution of a CT scanner is not related to which of the following?
    • A. 

      Focal spot size

    • B. 

      Section width

    • C. 

      Reconstruction algorithm

    • D. 

      Signal-to-noise ratio

  • 90. 
    The intensity of the CT xray beam can be increased by
    • A. 

      Increasing filtration

    • B. 

      Decreasing collimation

    • C. 

      Decreasing applied voltage

    • D. 

      Increasing collimation

  • 91. 
    Which of the following is a solid-state device used to record the light flashes given off by a scintillation crystal?
    • A. 

      Photomultiplier tube

    • B. 

      Anode

    • C. 

      Photodiode

    • D. 

      Input phosphor