Card Set Information

2012-05-16 01:25:30

ERT'S Review Q's
Show Answers:

  1. Which of the following is not considered part of the middle mediastinum
    A. Thoracic Aorta
    B. Superior Vena Cava
    C. Inferior Vena Cava
    D. Heart
    A. Thoracic Aorta
    (this multiple choice question has been scrambled)
  2. The trigger threshold for the Pulmonar Embolus CT exam is _____ HU.

    A. 100-200
    B. 50-90
    C. 90-100
    D . 0 - 50
    C. 90-100
    (this multiple choice question has been scrambled)
  3. Which of the following processes is associated with reconstructing volumetric acquired data to make the data look like individual slices?
    A. back projection
    B. pitch
    C. filtering
    D. Linear interpolation
    D. linear interpolation
    (this multiple choice question has been scrambled)
  4. Backprojection is associated with:

    A. artifacts
    B. increased image sharpness
    C. pitch
    D. helical/spiral scanning
    A. Artifacts
    (this multiple choice question has been scrambled)
  5. Which of the following techniques is used to reduce metal artifacts....Orthopedic Appliance?

    A. High Kvp/High MaS/decreased pitch
    B. High Kvp/Low Mas/decreased pitch
    C. High KvP/High MaS/increased pitch.
    D. Low KvP/low MaS/incrased pitch
    C. Increased KvP/Increased MaS/ Increased Pitch
    (this multiple choice question has been scrambled)
  6. Which of the following might be administered in a CT Urography to increase urinary output?
    A. Tadalafil
    B. Sildenafil Citrated
    C. Furosemide
    D. Glucogon
    C. Furosmide
    (this multiple choice question has been scrambled)
  7. The DAS is located:

    A. between the detectors and the ADC
    B. in the Gantry
    C. between the detectors and the DAC
    D. between the detectors and the computer
    D. Between the detectors and the Computer
    (this multiple choice question has been scrambled)
  8. Filament size is directly related to

    1 slice thickness
    2 mA selected
    3 spatial resolution

    A. 1 + 2
    B. 1 + 3
    C. 2 + 3
    D. 1+2+3
    D. 1+2+3

    All of the above
    (this multiple choice question has been scrambled)
  9. The diaphragm's movement depends of which of the following nerves?

    A. Phrenic
    B. Splanchnic
    C. Vagus
    D. Median
    A. Phrenic
    (this multiple choice question has been scrambled)
  10. The Renal Arteries correspond to the level of:

    A. L4
    B. T10
    C. L2
    D. T8
    C. L2
    (this multiple choice question has been scrambled)
  11. Backprojection is associated with:

    A. Pitch
    B. artifacts
    C. Increased imaga sharpness
    D. Helical/Spiral Scanning
    B. Artifacts
    (this multiple choice question has been scrambled)
  12. Which 3 veins empty into the portal Vein?

    A. Splenic,Gastric,SMA
    B. Gastric, IMA, SMA
    C. Splenic, IMA,SMA
    D. Splenic, Gastric, Hepatic
    C. Splenic, IMA,SMA
    (this multiple choice question has been scrambled)
  13. When image date is acquired by a CT scanner, it goes through a process known as:

    A. Digitization
    B. Convolution
    C. Quantization
    D. Photon Flux
    C. Quantization
    (this multiple choice question has been scrambled)
  14. What happens when you increase the Display field of view?
    • *More photons interact with the pixels.
    • * Noise decreases
    • *Spatial Resolution Decreases
    • *Larger pixels
  15. What happens when you decrease the display field of view?
    • *Smaller pixels
    • *Spatial Resolution increases.
    • *Noise increses
    • * Displays a larger area on the screen.
  16. How to improve Contrast Resolution?
    • *Higer mA
    • *Smaller Pt
    • *Larger DFOV
    • *Larger pixels
    • *Smaller Matrix
    • *Increase Collimation
    • *Smooth Filter

    Contrast resolution is improved when more photons reach the detectors. More noise decreases Contrast resolution. Technical factors that decrease noise increase contrast resolution.
  17. How to Improve Spatial resolution?
    • *Smaller detector size
    • *Smaller DFOV
    • *Smaller pixels
    • *Thinner slices
    • *Small focal spot
    • *narrow collimation
    • Ability of a scanner to display fine detail, sometimes referred to high contrast spatial resolution.
  18. What improves noise?
    • *Higher mAs
    • *Larger Pixels
    • *Larger Slice thickness
    • *Larger Display field of View

    *When ever more photons interact with the detectors, decrease the noise inherent in the image.
  19. Image linearity is defined as?

    A. Proportional increases in radiation with increases mAs
    B. Ability to assign the correct CT # to a given objects
    C. Compensation for Artifacts
    B. The relative accuracy between calculated CT # and their respective linear attenuation coefficient.
    (this multiple choice question has been scrambled)
  20. Spatial Resolution is best defines.

    A. Ability to image very small objects.
    B. Ability to reduce image noise
    C. Ability to destinguish low subject contrat tissue.
    D. Ability to image tissue with similar mass density
    B. Ability to image very small objects.
    (this multiple choice question has been scrambled)
  21. *Small pixel size, small detector size, thin slices, small focal spot, and narrower collimation improve image detail.
    *When you do anything that increases the noise levels in the image, you also improve the Spatial Resolution.
  22. Contrast resolution is improved by:

    A. Increasing KvP
    B. Increasing mAs
    C. Reducing Fov
    D. Reducing slice Thickness
    • B. Increasing mAs
    • *Thicker slices, imaging smaller pt, using low noise imagers, larger Fov, smaller matrix size, smooth reconstruction filters. Scatter radiation reduces contrast resolution

    * Anything that reduces noise increases Contrast resolution.
  23. Contrast resolution of a CT scanner is not related to which of the following:
    A. Section Width
    B. Focal Spot Size
    C. Reconstrucion algorithm
    D. Signal to noise ration
    B. Focal spot size.

    *Want everything large to reduce the inherent noise level. Focal spot size is the only thing that doesnt affect noise.
    (this multiple choice question has been scrambled)
  24. Spatial resolution is improved by:
    A. Small detector size.
    B. Small pixel size.
    C. Small voxel size.
    D. Small patient.

    *small detector size, small pixel size, small voxel size, small focal spot size, High freq filter, and narrow pre detector collimator. Anything that gives you higher image noise improves spatial resolution.
  25. Which of the following improve contrast resolution?

    A. Thicker slices.
    B. Bigger patients
    C. Large DFoV
    D. Reduce pixel size.
    • A.
    • C.

    Anything that reduced image noise improves contrast resolution. Larger FoV increases the size of the pixels thus reducing image noise, improving contrast resolution.
  26. 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. Modulation
    D. Linearity
    B. Contrast resolution.
    (this multiple choice question has been scrambled)
  27. Which of the following is reduced by the use of high KvP during CT?
    A. Photoelectric Absorption
    B. image dynamic range
    C. Xray tube loading
    D. radiactuve intesity @ the image receptor.
    • A. Photoelectric Absorption
    • C. Xray tube loading.

    Bean hardening is also reduced.
  28. Abdominal Aorta bifurcates at the level of :
    A. T10
    B. T12
    C. L2
    D. L4
    D. L4: where if bifurcates into the left and right common iliac artery. Caude Equina is also located at the level of L4

    The spinal coard ends at L2.
    (this multiple choice question has been scrambled)
  29. After the injection of IV contrast for a CT of the brain; what area does not enhance?
    A. Choroid Plexus.
    B. Anterior Communicating artery.
    C. Dura Mater.
    D. Posterior Horns of the Lateral Ventricle.
    D. Posterior Horns of the Lateral Ventricle

    *this area contains cerebral spinal fluid and doesnt enhance.
    (this multiple choice question has been scrambled)
  30. Ct scanning of the liver for tumor evaluation should not be performed during which phase of contrast enhancement?
    A. Non equilibrium
    B. Dynamic
    C. Bolus
    D. Equilibrium
    D. Equlibrium; its the lowest point of enhancement

    *the order is as follows: Bolus, Non equilibrium, Equilibrium.
    (this multiple choice question has been scrambled)
  31. The hepatic Arterial phase occurs about ____ seconds after the start of the IV injection?
    A. 20-40
    B. 0-20
    C. 60-80
    D. 40-60
    A. 20-40 seconds after injection.
    (this multiple choice question has been scrambled)
  32. The portal venous phase occurs at about ___seconds after the start of injection.
    A. 20-30
    B. 40-60
    C. 60-90
    D. 90-120
    C. 60-90

    *Hepatic early arterial 20-40 seconds; Portal venous @ 60-90secs
    (this multiple choice question has been scrambled)
  33. Which of the following would not enhance during the first several minutes of a post contrast CT study of the neck?

    A. Lymph nodes.
    B. Vascular lesion
    C. jugular Vein
    D. Internal carotid Artery
    A. Lymph Nodes
    (this multiple choice question has been scrambled)
  34. Which of the following is Considered to be Iso Osmolar contrast media?
    A. Iohexol
    B. Ioversol
    C. Iopemidol
    D. Iodixanol
    D. Iodixanol
    (this multiple choice question has been scrambled)
  35. The rest are all Non Ionic Low Osmolar Contrast media
  36. Non Ionic Low Osmolar Contrast Media
    Iohexol Omnipaque
    Iopamidol Isovue
    Ioversol Optiray
  37. Ionic High Osmolar Contrast Media
    Iothalmate Conray
    Diatrizoate Hypaque
  38. Radiation exposure and its potential harmful effects have a relationship that is termed_____in nature.
    A. Non-Stochastic
    B. Somatic
    C. Negligable
    D. Stochastic
    D. Stochastic

    Certain hermfull effects of exposrue to diagnostic xrays, such as cancer formation and genetic mutations are said to be random or Stochastic in nature

    Stochastic effects is one that has no threshold dose but increases in probability with increases dose.
    (this multiple choice question has been scrambled)
  39. Radiation dose index calculation that takes into account the variations in absorbption across the field of view due to beam hardening is termed

    A. CTDI 100
    B. CTDI vol
    C. CTDIw
    D. MSAD
    C. CTDI w

    is calculated from measurements made with dosimeter positioned at the center and periphery of a phantom and accounts for the veriences in dose distribution due to the effect of beam hardening.
    (this multiple choice question has been scrambled)
  40. Amount of xray energy absorbed in a unit of mass is measured in ?

    What is it?
    Gray Gy

    Its is the Absorbe dose.
  41. Type of tissue radiotion is deposited in?

    Measured in?
    Quantity of Absorbed radiation dose based on the radiosensitivity of a particular tissue is called?
    It is the Effective dose

    Measured in Seiverts
  42. Approximate mesure of the dose received in a single section or slice?
  43. Average cumilative dose to each slice within the center of a scan, consisting of multiple slices; including scatter radiation.
  44. Moderate reaction to contast media
    • *mild bronchospasm
    • *moderate to severe urticaria
    • *vasovagal response
    • *tachycardia from hypotension
  45. Severe reaction to contrast media
    • Profound hypotension
    • Laryngeal edema
    • Pulmonary edema
    • Severe bronchospasm
    • Chronic arrythmia
    • Seizures
    • Cardiopulmonary arrest
    • Death
  46. Normal unenhanced liver density measures?
    unenhanced density of 45-65
  47. Peak arterial phase for the liver?
    • Peak arterial enhancement of the liver is 25-35 secs after injection.
    • *hepatic arterial supply well opacified
    • *no parenchymal enhancement
    • -for early arterial is 15-20
  48. When does the Portal Hepatic venous Phase occur?
    • -60-70 seconds after injection.
    • -peak hepatic parenchyma enhancement.
    • -contrast redistributes from blood into extravascular spaces.
    • -demonstrates hypervascular lesions such as hepatic mets.
  49. When does the liver equilibrium phase occur?
    • - 2-3 minutes after injection
    • -hepatic parenchymal enhancement dissipitates
    • -minimal difference in contrast between intra/extavascular spaces
    • - many lesions become indistinguishable between surrounding tissue.
  50. When does the liver delayed phase occur?
    • 5-20 minutes after injection
    • -demonstrates the complete fill in of a hemangioma as it becomes isodense with the surrounding parenchyma
  51. When does the corticomedullary phase occur?
    • - late arterial phase 30-40 seconds
    • -optimal enhancement of the renal cortex/vein
    • -medulla minimally enhanced; allowing maximum differentiation from renal cortex.
  52. When does the nephrographic phase occur?
    • -70-90 secs after injection
    • -enhancement differences between renal cortex and medulla reach equillibrium
    • -optimal for lesions.
  53. When does the excretory phase occur?
    • -delayed imaging phase; 3 minutes after injection
    • -contrast agent becomes excreted into the renal calyces;opacifying the renal pelvis, ureters and bladder.
    • -visualized filling defects.
  54. When does the arterial phase of the Kidneys occur?
    * 20-25 secs delay; maximum opacification of the aorta/renal arteries.
  55. What is effective mAs?
    What is the formula for the effective mAs?
    • its is the calculated mas per aquired slice;
    • -primary factor is table speed