US Physics 391-420

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US Physics 391-420
2013-07-05 16:23:17

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  1. You are imaging a 3D dataset that has anisotropic resolution. What does this mean?
    Unequal resolution is present between imaging planes
  2. The two sagittal images of an artery were obtained with different transducers. What type of resolution is limiting visualization of the arterial lumen in the image on the left?
    Slice thickness
  3. You are imaging a fluid-filled structure that has equidistant horizontal bands appearing in the near field. The bands have decreasing brightness with depth. What artifact are you imaging?
  4. The waveform you obtained from an arterial stenosis demonstrates aliasing. If you increase the pulse repetition frequency to eliminate the aliasing, what artifact could be introduced?
    Range ambiguity
  5. You have obtained an ultrasound image that demonstrates refraction of the sound beam. This artifact might be manifested as:
    Lateral displacement of the displayed position of a reflector
  6. Which of the following conditions will result in aliasing of the Doppler frequency shift using continuous-wave Doppler?
    None of the above
  7. You obtained a 3D sweep in an axial plane and are viewing it in a multiplanar display. What orthogonal planes will be displayed?
    Coronal and sagittal
  8. You are using a transducer that produces a beam with a very wide slice thickness. Which of the following problems are you most likely to encounter as a result?
    Partial volume artifact
  9. Which technology would be most helpful to obtain accurate anatomic volume measurements?
    3D imaging
  10. You may observe a mirror image artifact with which imaging mode?
    B-mode, Spectral Doppler, Color Doppler and Power Doppler (All of the above)
  11. Which of the following artifacts may result in both an axial and lateral displacement of a reflector on the ultrasound image?
    Multipath reflections
  12. Which imaging technique may increase visualization of the reflections from blood flow on the real-time ultrasound image?
    Tissue harmonic imaging
  13. While scanning a curved structure, you notice shadowing at the lateral edges of the structure. What is required for this artifact to occur?
    Different media propagation speeds
  14. What artifact is being described in the previous question?
  15. The range equation describes the relationship between:
    Round-trip pulse travel time and distance to the reflector
  16. Requirements of magnetic field tracking for 3D reconstruction include:
    Minimization of electromagnetic inference, Transmitter must be in close proximity to the receiver and ferrous metals must not be within the electromagnetic field (All of the above)
  17. Which of the following artifacts is the result of reverberation?
    Comet tail
  18. Which of the following artifacts commonly results in echoes filling in the lumen of small vessels?
    Partial volume
  19. Propagation speed error results in which sonographic appearance?
    Improper axial position of an echo
  20. When you select harmonic imaging, which artifact is less likely to be observed?
    Grating lobes
  21. When you select compound imaging, which artifact is less likely to be observed?
    Refraction, Shadowing, Enhancement or Acoustic speckle (All of the above)

  22. The salt and pepper appearance you observe in this ultrasound image is a result of:
    Acoustic speckle

  23. This image exhibits banding. This is a result of:
    Incorrect TGC

  24. What imaging artifact is much worse on the left phantom image compared to the right phantom image?
    Volume averaging
  25. What type of transducer will you improve the artifact demonstrated in the previous question?
    1.5D or multi-row array

  26. This image was obtained with a linear array transducer that employs phasing to steer the beam. What artifact do the arrows point to?
    Grating lobes
  27. What can be done to reduce the presence of the artifact seen in the previous question?
    Reduce or eliminate beam steering
  28. Complete destructive interference of echo reflections will affect the display in the following way:
    Black pixel
  29. You are observing a sonographic artifact based on the interference patterns of scattered echoes. What artifact are you imaging?
    Acoustic speckle
  30. Which of the following will improve the artifact you are imaging in the previous question?
    Use frame averaging and compound imaging