CT

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Njmel74
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CT
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2013-11-08 18:14:47
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CT Review
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  1. If a reconstruction FOV of 32 cm & a
    512x512 matrix are used, what is the pixel size:
    A) 0.35x0,35 mm
    B)0.625x 0.625mm C) 1.6x 1.6mm D) 3.25x3.25mm
    B)0.625x 0.625mm
  2. Tungsten is used as the target material on the tube's anode because it has a _____ atomic number and a _____ melting point.
    A. low, low
    B. low, high
    C. high, low
    D. high, high
    B
  3. Using _____ reconstruction filter would decrease the appearance of noise in a CT image.  1. no  2. a smooth 3. a sharp
    A. 1 only
    B. 2 only
    C. 3 only
    D. 2 & 3
    E. 1 & 3
  4. Which of the following is NOT
    an indication of a herniated disk?
    1. deformity of the posterior border
    of the disk
    2. displacement of epidural fat
    3. hypertrophy of the inferior
    articulating process and lamina
    3 only
  5. Which of the following may result from exposing an embryo to x-ray radiation?1. deformities2. mental retardation3. miscarriage
    All the above
  6. Which of the following may occur if the patient's arms are placed at
    their sides during a chest exam if the scan field-of-view is 33 cm?
    1. beam hardening
    2. cone beam artifact
    3. out-of-field artifact
    1 and 3
  7. Which of the following is TRUE regarding ionic contrast agents?
    1. ionic agents are charged ions
    2. ionic agents dissociate into ions in
    solution
    3. ionic agents ionize tissues they contact
    2 only
  8. What are typical start and end locations for CT scans of the pelvis?
    from the iliac crest through the symphysis pubis
  9. _____ in the image is a possible manifestation of patient motion.
    1. Blurring
    2. Ghosting
    3. Streaks
    All of them
  10. Which of the following is NOT directly proportional to mAs?
    A.dose to the patient
    B.the mean energy of the x-ray photons leaving the tube
    C.the number of x-ray photons leaving the x-ray tube
    D.x-ray tube heating
    B
  11. A CT system manufacturer has a scanner in which the focal spot of the
    x-ray beam can move to two, slightly separated, distinct locations. 
    What benefit does the dual focal spot provide compared to an identical
    scanner possessing a single focal spot?
    1. the number of projections is
    doubled
    2. the number of rays in a single projection is doubled
    3. the patient dose is halved
    1 only
  12. A CT Number Calibration Test should be performed:
    Daily
  13. A delay of about _____ seconds after the start of the IV contrast injection should be used for a helical scan of the neck.
    35
  14. An indication for IV contrast injection is to rule out:
    A.Grave's disease B.mastoiditis C.meningioma D.sinusitis
    C.meningioma
  15. The enormous heat that builds up in the CT tube is caused by the:
    A.intensity of the x-rays emitted from the tube
    B.electron beam between the cathode and the anode in the tube
    C.collision of the electron beam with the tungsten target on the tube anode
    D.x-ray filter in the tube which absorbs the lower energy photons before they can enter the patient
    C
  16. Which of the following men was awarded the first Nobel Prize in Physics in 1901?
    a. Geoffrey Newton
    b. Godfrey Newbold Hounsfield
    c. Wilhelm Conrad Rontgen
    d. Albert von Kolliker
    C
  17. The detectors:
    (Choose one answer)
    a. shield the patient from x-rays
    b. produce the beam of x-rays
    c. increase the x-ray exposure of the film
    d. measure the x-rays that pass through the patient's body
    D
  18. The first commercial CT scanner was available during the:
    1970s
  19. A detector array (choose 1 answer)
    a. is stationary in all scanner designs commercially available today
    b. was first seen on third-generation CT scanners
    c. rotates around the patient in all scanner designs
    d. allows for much faster data collection than using a single detector
    D
  20. Fourth-generation CT scanners _________ while third-generation CT scan­ners do not.
    a. have the capability of advanced scanning techniques
    b. apply fan beam geometry
    c. have detectors which rotate
    d. have a detector ring which does not rotate
    D
  21. Which of the following events is responsible for changing the raw data into image data?
    a. attenuation
    b. ionization
    c. reconstruction
    d. reconversion
    C
  22. ____________________ made helical imaging possible
    a. The introduction of second-generation technology
    b. The introduction of fourth-generation technology
    c. Continous rotation scanners
    d. Multi-row detector scanners
    C
  23. The main purpose of the detector is to:
    a. provide additional collimation in order to reduce scatter
    b. capture x-ray photons and convert them to a measurable signal
    c. limit the x-ray dose to the patient
    d. amplify the measured signal
    B
  24. Which of the following is a lab test to determine if the blood will properly coagulate? (more than 1)
    a. BUN
    b. platelet count
    c. PTT
    B and C
  25. ____________ BPM is considered a normal pulse rate for an infant
    a. 45
    b. 60
    c. 85
    d. 130
    D
  26. The slip ring on a CT scanner: (>1)
    a. prevents the high voltage cable from winding up
    b. advances the patient table
    c. alleviates the need for reversal of the rotating assembly to which the tube is attached
    A and C
  27. What is the most common type of film used for recording CT images?
    a. paper
    b. thermal
    c. single emulsion
    d. double emulsion
    C
  28. Which technology do multi-row detector scanners employ?
    a. first-generation
    b. second-generation
    c. third-generation
    d. fourth-generation
    C
  29. Which of the following is a lab test to determine if the kidneys are properly removing impurities from the blood?
    a. creatinine
    b. PT
    c. platelet count
    d. PTT
    A
  30. Which of the following is NOT a contraindication for a CT exam? (>1)
    a. aneurysm clips
    b. cardiac pacemakers
    c. allergy to shellfish
    ALL
  31. Which of the following is considered a normal adult blood pressure?
    a. 100mm Hg/70 mm Hg
    b. 140mm Hg/100 mm Hg
    c. 70mm Hg/100 mm Hg
    d. 80mm Hg/40 mm Hg
    A
  32. A 25 year old female is scheduled for a CT scan of the sinuses. She is not absolutely certain that she is not pregnant and it has been three weeks since her last menstrual period. What is the best course of action?
    postpone the procedure until she is more certain of her condition
  33. The most common catheter size used in CT is:
    a. 12 to 14
    b. 15 to 17
    c. 18 to 22
    d. 23 to 25
    C
  34. The osmolality of plasma is __________mOsm/kg
    a. 175
    b. 235
    c. 285
    d. 325
    C
  35. How long does it take to inject 150 ml of contrast media with an injection rate of 2 ml/sec.?
    75 seconds
  36. Which of the following may help to reduce adverse reactions resulting from the administration of IV contrast media?
    a. use high osmolar contrast media
    b. administer an antihistamine prior to the IV contrast injection
    c. increase the rate of injection
    B
  37. Which of the following oral contrast agents is better for opacifying the distal small intestine?
    a. an ionic iodinated contrast agent
    b. a non-ionic iodinated contrast agent
    c. barium sulfate
    C
  38. The definition of osmolality is the ____________the contrast agent solution.
    a. thickness of
    b. measure of dissociation of
    c. concentration of molecular particles in
    d. rate of injection of
    C
  39. The heating unit on a power injector is for ___________of the contrast agent.
    a. increasing the iodine concentration
    b. decreasing the viscosity
    c. increasing the density
    d. decreasing the osmolality
    B
  40. Which of the following characteristics of an IV contrast agent affects patient tolerance? (>1)
    a. concentration of iodine
    b. osmolality
    c. viscocity
    ALL
  41. Why is the cephalic vein a less desirable site for injection than the basilic vein?
    a. it is usually a very small vein with poor blood flow
    b. the blood must traverse the vessels in the head before reaching the heart
    c. it is a deep vein and not easily catheterized
    d. flow may be impeded as the patient's arms are raised
    D
  42. Which of the following is NOT a typical adverse reaction to oral contrast media (Barium) used in CT?
    a. diarrhea
    b. abdominal cramping
    c. flatulence
    d. hives
    D
  43. When a contrast agent is injected directly into the joint space it is known as ______________contrast.
    a. intravenous
    b. intrathecal
    c. oral
    d. intraarticular
    D
  44. Which of the following is TRUE regarding ionic contrast agents?
    a. ionic agents are charged ions
    b. ionic agents dissociate into ions in solution
    c. ionic agents ionize tissues they contact
    B
  45. What is the appropriate care to give to a patient with diabetes.(>1)
    a. if IV contrast media is required, use LOCM
    b. ifthe patient is using Metformin, advise them to stop its use 48 hours before IV contrast is administered
    c. if the patient on Metformin, to resume its use 48 hours after IV iodine only after kidney reassessed
    A and C
  46. Barium sulfate oral contrast media would be selected instead of iodinated oral contrast media because:
    a. it passes through the GI tract more quickly
    b. the trauma patient may have a perforated bowel
    c. the contrast media stays more dense in the distal GI tract
    C
  47. Which of the following is a result of injecting a hypertonic solution into the vascular space?
    a. there is a net movement of water into the vascular space
    b. there is a net movement of contrast media out of the vascular
    c. there is a net movement of water out of the vascular space
    A
  48. Viscosity is a measure of a fluid's:
    a. atomic weight
    b. thickness
    c. temperature
    d. injection rate
    B
  49. The definition of osmolality is the ____________the contrast agent solution.
    a. thickness of
    b. measure of dissociation of
    c. concentration of molecular particles in
    d. rate of injection of
    C
  50. A common formula used to calculate dosage of intravenous iodinated contrast material in the pediatric patient is:
    a. 3 mg per kg body weight
    b. 5 mg per kg body weight
    c. 1 ml per lb or 2ml per kg body weight
    d. 100 mL over 10 lbs
    C
  51. During a CTA of the brain's circle of Willis, if an iodinated contrast agent is injected at a rate of 3-4 mL/sec, an adequate delay for optimal vessel opacification would be in the range of:
    a. 4-10 seconds
    b. 12-20 seconds
    c. 45-60 seconds
    d. 60-90 seconds
    B
  52. During IV contrast agent administration for peripheral CTA examinations, the bolus duration should be equal to the scan time minus _____ seconds.
    5
  53. The normal range of glomerular filtration rate (GFR) for women is:
    a. 50 ± 14 mL/min/m²
    b. 60 ± 10 mL/min/m²
    c. 70 ± 14 mL/min/m²
    d. 80 ± 10 mL/min/m²
    B
  54. A patient has a severe vagal reaction to iodinated contrast material that includes bradycardia. Initial treatment may consist of:
    a. atropine
    b. diazepam
    c. Zantac
    d. Proventil
    A
  55. Parenteral contrast administration refers to which of the following?
    a. oral administration
    b. rectal administration
    c. intravenous administration
    d. nasogastric administration
    C
  56. Glomerular filtration rate (GFR) is a laboratory assessment test utilized to measure:
    a. blood coagulation
    b. respiratory function
    c. cardiac function
    d. renal function
    D
  57. Cupping artifacts most commonly occur in the:
    a. chest
    b. abdomen
    c. pelvis
    d. brain
    D
  58. Which of the following is capable of causing an edge gradient artifact?
    A. detector malfunction
    B. dense bone
    C. involuntary patient motion
    D. tube arcing
    B. The edge gradient effect occurs at areas of abrupt change in density, which are represented by high spatial frequency signal. The computer may have difficulty interpreting this type of rapidly changing information, and streaks may appear as a result. The interface between dense bone and soft tissue is a common site for the edge gradient effect to occur.
    (this multiple choice question has been scrambled)
  59. A straight line appearing vertically on the scanogram (pilot/scout) of a fourth-generation CT scanner is an artifact most likely caused by:
    a. edge gradient
    b. detector malfuction
    c. tube arcing
    d. beam hardening
    B
  60. The lumens of needles used for the injection of contrast media vary in diameter. The unit used to describe this diameter is called:
    gauge
  61. Which of the following section widths would cause the greatest amount of partial volume averaging?
    A. 5 mm
    B. 3 mm
    C. 1 mm
    D. 10 mm
    D. Large section widths result in long voxel lengths with possibly several tissue types accounted for within the voxel. When a CT number is assigned to the representative pixel, the density of all of the tissue types is averaged, yielding one attenuation coefficient. Narrow section widths tend to decrease the partial volume effect.
    (this multiple choice question has been scrambled)
  62. Which of the following are possible results of partial voluming?
    a. decreased sharpness of edges
    b. misleading CT numbers
    c. improvement in resolution
    A and B
  63. Which of the following parameters is responsible for partial volume averaging?
    a. matrix size
    b. kVp
    c. slice thickness
    d. patient dose
    C
  64. Which scanning plane is best for evaluating the anatomical relationship between the pituitary and the sella turcica?
    a. transverse
    b. oblique between transverse and sagittal
    c. coronal
    d. sagittal
    C
  65. What is the appropriate range of coverage for a coronal sinus study?
    from the dorsum sella to the anterior aspect of the frontal sinus
  66. In which of the following studies might cranial nerve VII be visualized?
    a. internal auditory canal
    b. cervical spine
    c. soft tissue neck
    d. supratentorium
    A
  67. Which of the following would NOT enhance during the first several minutes of a post-contrast CT study of the neck?
    a. vascular lesion
    b. lymph nodes
    c. jugular vein
    d. internal carotid artery
    B
  68. In which of the following studies might cranial nerve XI be visualized?
    a. soft tissue neck
    b. lumbosacral spine
    c. supratentorium
    d. internal auditory canal
    A
  69. For CT brain scans, the reference line for axial slices may be which of the following? (>1)
    a. cantomeatal line
    b. orbitomeatal line
    c. infraorbitomeatal line
    ALL
  70. Which of the following is the typical scan delay after the initiation of injection of contrast media for studies of the liver?
    a. 15 to 25 seconds
    b. 65 to 75 seconds
    c. 85 to 95 seconds
    d. a few minutes
    B
  71. Which system component converts the projection attenuation data into the proper digital form for the array processor?
    a. detector
    b. photodiode
    c. analog-to-digital converter
    d. host computer
    C
  72. Tube interscan delay time refers to:
    a. the time between the end of one scan and the start of the next scan during which the tube will cool
    b. a quality assurance test performed daily by the technologist
    c. the time required for the tube to make a complete 3600 revolution
    d. the length of time required for the production of photons to begin after applying the voltage to the tube
    A
  73. The main purpose of the detector is to:
    a. provide additional collimation in order to reduce scatter
    b. limit the x-ray dose to the patient
    c. capture x-ray photons and convert them to a measurable signal
    d. amplify the measured signal
    C
  74. Which ofthe following is a component NOT normally located in the gantry of a modern CT system?
    a. pre-patient collimator
    b. solid-state detectors
    c. array processor
    d. x-ray tube
    C
  75. Which of the following CT scanner designs does NOT use an x-ray tube?
    a. first-generation CT
    b. PET/CT
    c. electron beam CT
    d. MDCT
    C
  76. ________ allows helical data to be converted into planer raw data.
    A. Cone beam reconstruction
    B. Convolution
    C. Interpolation
    D. Retrospective reconstruction
    C
  77. Which of the following combinations of scanning parameters is best for evaluating abnormalities within the petrous pyramids of the temporal bones?.
    A.sharp algorithm, window width = 2500, 0.5 to 3 mm slices
    B.soft algorithm, window width = 300, 0.5 to 3 mm slices
    C.standard algorithm, window width = 300, 0.5 to 3 mm slices
    D.standard algorithm, window width = 2500, 4 to 8 mm slices
    A
  78. Which of the following may reduce the out-of-field artifact?
    A.increasing the matrix
    B.increasing the scan field-of-view
    C.reducing the slice thickness
    D.reducing the reconstruction field-of-view
    B
  79. Which of the following parameters causes helical
    slices to be reconstructed so they overlap?
    A.collimation
    B.pitch
    C.reconstruction interval
    D.table increment
    C
  80. On a CTA exam of lower extremity vasculature to assess atherosclerosis, coverage should extend from the _____ to the _____.
    A.abdominal aorta; ankles
    B.abdominal aorta; iliac arteries
    C.iliac arteries; femoral arteries
    D.iliac arteries; popliteal arteries
    A
  81. Which of the following provides the best bone window setting for the pelvis?
    A.window width = 100, window level = -200
    B.window width = 140, window level = 60
    C.window width = 1000, window level = 200
    D.window width = 2000, window level = 350
    D
  82. There is substantial enhancement of the liver compared to tumors during the _____ phase, but during the _____ phase, there is the possibility oftumor enhancement, which may make hepatic tumors isodense with liver tissue.
    A.bolus; equilibrium
    B.equilibrium; non-equilibrium
    C.non-equilibrium; bolus
    D.non-equilibrium; equilibrium
    D
  83. A difference in density of _____ HU between the aorta and the inferior vena cava would indicate the non-equilibrium phase of enhancement.
    A. 8
    B.25
    C.35
    D.43
    B
  84. What is the cause for the cupping artifact?
    the tissues of the body attenuate low energy photons
  85. If a reconstruction FOV of 32 cm and a 512 x 512 matrix are used, the pixel size is _____ mm.
    A.0.35 x 0.35
    B.0.625 x 0.625
    C.1.6 x 1.6
    D.3.25 x 3.25
    B. Pixel size = reconstruction FOV/matrix. Pixel size =320 mm/512.
    (this multiple choice question has been scrambled)
  86. Which of the following would be used to better visualize low contrast
    resolution?
    1 decreased mAs
    2. narrow window width
    3. sharp reconstruction
    filter
    2
  87. ______ the window _____ will make the image appear darker so that bony structures can be evaluated.
    Increasing, level
  88. An increase in _____ does NOT occur in the resulting images when applying a sharp, or high-pass reconstruction filter during the image reconstruction of CT raw data.
    1. contrast resolution
    2. edge enhancement
    3. the appearance of noise
    1
  89. Which of the following will have the least likelihood of producing edge gradient artifacts?
    A.thick slices with full scan
    B.thick slices with partial scan
    C.thin slices with full scan
    D.thin slices with partial scan
    C
  90. A kernel is a:
    A. component in the x-ray tube
    B. filter applied to the CT raw data
    C. post-processing filter applied to image data
    D. type of detector
    B
  91. Which of the following is a reason to increase the pitch?
    1. radiation dose to the patient can be increased
    2. a given volume of anatomy can be covered faster
    3. a greater volume of anatomy can be covered in a given time
    2 and 3
  92. CT numbers _____ would appear black if a window width of 400 and a window level of -100 are used.
    A.below -200
    B.below -300
    C.above +200
    D.above +100
    B
  93. Which of the following is the order in which the phases of IV contrast enhancement occur?
    A.bolus, equilibrium, non-equilibrium
    B.bolus, non-equilibrium, equilibrium
    C.equilibrium, non-equilibrium, bolus
    D.non-equilibrium, bolus, equilibrium
    B
  94. What is the complete name of the laboratory test known as PTT?
    partial thromboplastin time
  95. Which of the following window settings provides the best tissue differentiation of the soft tissues of the abdomen?
    A.window width = 100, window level = - 200
    B.window width = 300, window level = 40
    C.window width = 1000, window level = 200
    D.window width = 2500, window level = 350
    B
  96. If a calcification with a CT number of +300 appears pure white on an image, which of the following could be the window width and window level selected?
    1. window level = 0, window width = 5002.
    2.window level = +300,window width = 5003.
    3.window level = +100, window width = 1000
    1
  97. Which of the following window settings provides the best tissue differentiation of the soft tissues of the supratentorium?
    A.window width = 100, window level = 30
    B.window width = 300, window level = 60
    C.window width = 1000, window level = 200
    D.window width = 2500, window level = 350
    A
  98. Which of the following utilizes convolution?
    1. 3D SSD
    2. filtered back projection
    3. Fourier transform
    2
  99. On MDCT, the final reconstructed slice
    thickness is determined by the:
    A.collimation of the x-ray beam
    B.number of rows of detectors and the size oft he detectors whose attenuation data gets combined
    C.pitch
    D.reconstruction interval
    B
  100. Which of the following will result in an increased voxel size?
    1. decreased reconstruction FOV
    2. increased matrix
    3. increased slice thickness
    3

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