Card Set Information

2012-09-11 03:04:34

Show Answers:

  1. Which ultrasound system control automatically calibrates for measurements?

    overall gain
    near gain

    depth control automatically adjusts (or calibrates) depth markers.
  2. True/False:  Increasing system gain can reduce technical artifacts.

    increasing gain will increase specular echoes, which generally increases artifacts
  3. True/False: The purpose of the time-gain compensation circuit is:

    * to suppress near-field echos
    * to enhance far-field echos
    * to selectively eliminate weak echos
    * to compensate for loss of ultrasound energy(attenuation)     as the bean enters the body
    T, T, F, T

    TGC is important in defining the septal border, the thickness of the right ventricular anterior wall, and right-sided valves. It allows the operator to compensate for stronger echo initially and weaker echoes farther into tissue. It suppresses near field stronger echoes and enchaces far-field echoes, thereby compensating for attenuationg of the beam
  4. True/False:  Which of the following are True/False regarding the side lobes seen in 2D images?

    * they are generated from the edges of individual transducer elements
    * they are greater problem with mechanical systems
    * they are greater problem with phased-array system
    * they display fuzzy areas on the image
    T, F, T, T

    side lobes are a greater problem in phased-array systmes because the number of small transducer used results in multiple edges. Each edge may generate radially directed sound energy, overlapping and producing artifacts
  5. True/False: In PLAX transducer position, imaging is being done from the wrong intercostal space when: 

    * the IVS and the anterior aortic root wall meet at the right angle
    * the IVS and the anterior aortic root wall are contiguous
    * the IVS septum and the anterior aortic root wall do not meet
    * the IVS and posterior aortic root wall meet
    T, F, T, T

    only correct image is plax plane is continuity between the IVS and the anterior aortic root wall.
  6. With which of the following conditions would a contrast agent NOT likely be used to enhance the echo diagnosis?

    * atrial septal defect
    * idiopathic hypertrophic subaortic stenosis
    * ventricular septal defect
    * patent ductus arteriosus
    idiopathic hypertrophic subaortic stenosis

    contrast agents are more helpful in defining suspected shunts
  7. True/False:  L to R shunts are more difficult than R to L shunts to detect with peripheral-vein contrast injections because:

    * contrast is totally filtered out at the pulmonary capillary level
    * negative contrast is not as easy to identify as positive contrast
    * microbubbles will not travel left to right because of pressure difference
    * microbubbles traveling from right to left are rare and difficult to see
    F, T, F, T

    contrast is totally filtered out at the pulmonary capillary level, but this does not effect the L-R shunt. Negative contrast, meaning an area of no contrast in the right chamber is difficult to bring out in echo. Some L-R shunts have a small R-L component that will show some contrast on the left side, but this is usually a small amount and not easily to define on echo
  8. In which conditions could amyl nitrate be useful?

    mitral stenosis
    atrial septal defect
    aortic stenosis
    idiopathic hypertrophic subaortic stenosis
    idiopathic hypertrophic subaortic stenosis

    amyl nitrate may increase the systolic anterior motion of the anterior mitral valve leaflets in IHSS
  9. True/False:  In the patient with HOCM with no systolic anterior motion at rest, SAM may be demostrated by the use of:

    valsalva maneuver
    amyl nitrite
    T, T, F, F

    neither inspiration nor expiration affects SAM, but both valsalva maneuver and amyl nitrate inhalation may bring it out
  10. True/False:  When using a large sample volume in performing a Doppler examination, the operator:

    lengthens the examination time
    minimizes the chances of missing jets
    increases the chances of erroneously detecting flow in adjacent chambers
    reduces the sensitivity of the instruments
    F, T, T, F
  11. The A4 chamber veiw is frequently the first approach for a Doppler study because:

    * it is the easiest location from which to obtain image and doppler information
    * transducer is closest to the valves in this position
    * Doppler bean is parallel to the flow through multiple valves
    * more aabnormalities can be identified from this location
    Doppler bean is parallel to the flow through multiple valves
  12. True/False:  PLAX are good for Doppler applications because of the relationship of angle of flow.