Romans Chapter Review Questions

  1. Which of the following is NOT housed within the gantry?



    B. three-phase generator
  2. The power capacity of the generator is listed in:



    A. kilowatts (kW)
  3. A brush-like apparatus that provides continuous electrical power and electronic communication across a rotating surface is know as a ________.
    Slip ring device
  4. Which is a disadvantage of a small focal spot?



    C. reduced heat capacity
  5. The ability of the tube to withstand the by-product heat is called:
    a. heat capacity
    b heat dissipation
    c. thermal potential
    thermal transference
    a. heat capacity
  6. Image Upload 1
    In figure 2-1, what is the object marked X called?



    D. bowtie filter
  7. Regarding the detectors in the CT sstem, geometric efficiency is controlled primarily by:
    Aperture and detector spacing
  8. Which of the following is a characteristic of xenon gas detectors?



    C. low efficiency
  9. Image Upload 2
    Figure 2-2 illustrates a scanner with:



    d 5h generation design
    B. 3rd generation design
  10. Which component of the CT system converts the electric signals supplied by the detectors into a digital format?



    A. analog to digital converter
  11. compared with conventional radiographic images, CT localizer images 



    D. are of slightly poorer quality

    LOCALIZER is the key word!
  12. table movement per rotation divided by beam width is defined as:
    beam pitch

    pitch = chart?chf=bg,s,00000000&cht=tx&chl=%5Cfrac%7Btable%20.movement%20.per%20.rotation%7D%7Bbeam%20.width%7D&chs=402x74
  13. The number of slices multiplied by slice thickness is defined as:
    Beam width

    chart?chf=bg,s,00000000&cht=tx&chl=width%3D%23%20of%20Slices%5Ctimes%20thickness&chs=450x36
  14. How many CT numbers are assigned to each pixel in the image matrix?



    B. one
  15. which is another name for raw data?



    A. scan data
  16. An object that appear in an image but is not present in the object scanned is called a(n):
    artifact
  17. scan thickness is primarily important for the part it plays in:



    D. volume averaging
  18. Which is NOT a synonym for the preliminary (or localizer) image taken at the start of a CT examination?



    C. spiral
  19. The ability of a system to differentiate, on the image, objects with similar densities is known as:



    A. low contrast resolution
  20. each two-dimensional square of data that make up the CT image is called a:
    pixel
  21. A precise set of steps to be performed in a specific order to solve a problem describes a(n)
    algorithm
  22. the DAS reads each arriving ray and measures how much of the beam had been attenuated. this is



    D. a ray sum
  23. A complete set of ray sums is known as a
    view
  24. The process of converting the data from the attenuation profile to a matrix is known as:



    C. back-projection
  25. The process of applying a filter function to an attenuation profile is known as:



    B. convolution
  26. Increasing the scan field of view:



    C. increases the number of detector cells collecting data
  27. Changing the <SFOV or DFOV> will affect the image quality by changing the amount of raw data that is averaged together for each pixel.
    DFOV
  28. Tissue types with similar densities should be displayed in a ________ window width.
    • Narrow
    • 50-500 HU
  29. Tissue types that vary greatly in density should be displayed in a __________ window width.
    • Wide
    • 500-2000 HU
  30. A standard deviation of ___ indicates that every pixel within the ROI has the same HU.
    0

    A standard deviation of 0 indicates that every pixel within the ROI has the same HU.
  31. What HU values are in the naturally occurring range (i.e. not man made objects like surgical clips)?



    D. -1000 to 1000
  32. decreasing the window width in a CT image decreases



    A. the anatomic diversity displayed
  33. Increases the ____ increases the number of electrons that will produce x-ray photons.
    mA

    Increases the mA increases the number of electrons that will produce x-ray photons.
  34. Reducing the ____ while holding the ____ constant reduces the radiation dose to the patient.
    • mAs
    • kVp

    Reducing the mAs while holding the kVp constant reduces the radiation dose to the patient.
  35. The ____ setting defines the quality (or average energy) of the beam.
    kVp

    The kVp setting defines the quality (or average energy) of the beam.
  36. Image accuracy is also referred to as image _______.
    Fidelity
  37. Quantum mottle is also known as:
    image noise
  38. What is spatial frequency?


    B. the number of line pairs visible per unit length
  39. Typically only _______ and ______ MPR's can be programmed to be automatically generated.
    sagittal & coronal
  40. Another name for surface rendering is:



    B. segmentation
  41. An MIP is a good method to display all of the following EXCEPT:



    A. pulmonary nodules
  42. What type of 3D display is depicted in the picture below:




    Image Upload 3
    B. MinIP
  43. Which has become the favored 3D imaging in CT?



    B. Volume rendering
  44. VR techniques assign each voxel an opacity value based on its ______.



    C. Hounsfield units
  45. The process of selectively removing or isolating information from the 3D data set is referred to as:



    D. segmentation
  46. What is the cause of the artifacts in the image below?




    Image Upload 4
    A. metallic objects
  47. What does DICOM stand for?
    Digital Imaging and Communication in Medicine
  48. What does PACS stand for?
    Picture Archive and Communication System
  49. A compression method is said to be __________ if not image data are lost during the process.
    Lossless
  50. ________ compression methods introduce compression artifacts.
    Lossy
  51. What is the approximate normal range for blood urea nitrogen (BUN) and what does it measure?



    B. 7-25mg/dL, kidney function
  52. What is the approximate normal range for serum creatinine and what does it measure?



    B. 0.6-1.7mg/dL, kidney function
  53. What is the approximate normal range for estimated glomerular filtration rate (eGFR) and what does it measure?



    A. >60mL/min/1.73m2, kidney function
  54. What is the approximate normal range for prothrombin time (PT) and what does it measure?



    C. 11-14 seconds, blood coagulation ability
  55. What is the approximate normal range for partial thromboplastin time (PTT) and what does it measure?



    C. 25-35 seconds, blood coagulation ability
  56. What is the approximate normal range for partial thromboplastin time (PTT) and what does it measure?



    B. 150,000-400,000mm3, blood coagulation ability
  57. TRUE or FALSE: Wrist immobilizers must be used if leg immobilzers are used.
    • True
    • Wrist restraints are used to ensure the pt will not unsafely loosen the restraints or unintentionally hang themself off the table or gurney.
  58. What is the average adult pulse?
    60-100 beats per minute
  59. What is the average pulse rate for a child?  Infant?
    child: 95-110 bpm

    infant: 100-160 bpm
  60. What is the normal respiration rate of an adult? child? infant?
    • adult: 14-20 
    • children: 22-28
    • infants: 30 or greater
  61. What is the average range of systolic blood pressure? diastolic?
    systolic: 90-140

    diastolic: 60-90
  62. Children typically have ______ blood pressure than adults while the elderly tend to be _______.
    • Children- lower
    • elderly- higher
  63. For which of the following examinations is it common to check lab results for (PT), (PTT), and platelet count?



    A. CT-guided biopsy
  64. What is the atomic number of iodine?
    53
  65. The majority of severe reactions occur within the first _______ after contrast medium injection
    20 minutes

    Monitor high risk patients for at least an hour after contrast injection
  66. TRUE or FALSE: Asthma is a risk factor for reaction to contrast.
    True

    pts w/ asthma have 8 times the risk of reaction to HOCM and 5 times for LOCM
  67. TRUE or FALSE:
Author
RadiationTherapy
ID
347486
Card Set
Romans Chapter Review Questions
Description
Romans CT Exam Review: chapter review questions
Updated