Textbook of Diagnostic Sonography 8th Edition Hagen-Ansert Test Bank Chapter 07: Imaging and Doppler Artifacts Hagen-Ansert: Textbook of Diagnostic Sonography, 8th Edition MULTIPLE CHOICE 1. Lack of axial and lateral resolution result in: a. echoes originating only from the center of the beam. b. decrease in ultrasound pulse length and width in the scan plane. c. Failure to resolve structures and detail loss. d. beam width artifacts on the scan plane. ANS: C Axial and lateral (detail) resolutions are artifactual because a failure to resolve means a loss of detail, and two adjacent structures may be visualized as one. PTS: 1 REF: p. 120 OBJ: List ways in which sonographic gray-scale images can present anatomic structures incorrectly. TOP: Propagation 2. Multiple reflections can occur between the transducer and a strong reflector. This is an example of: a. reverberation. b. mirror image. c. speckle tracking. d. refraction.
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U S N T O ANS: A The multiple echoes may be sufficiently strong to be detected by the instrument and to cause confusion on the display. The multiple reflections are placed beneath the real reflector at separation intervals equal to the separation between the transducer and the real reflector. PTS: 1 REF: p. 120 OBJ: Describe how specific artifacts can be recognized.
TOP: Propagation
3. The artifact that shows structures that exist on one side of a strong reflector as being present on the other side as well is known as: a. range ambiguity. b. mirror image. c. refraction. d. speed error. ANS: B Mirror-image artifacts also a form of reverberation, shows structures that exist on one side of a strong reflector as being present on the other side as well. PTS: 1 REF: p. 121 OBJ: List ways in which sonographic gray-scale images can present anatomic structures incorrectly. TOP: Propagation
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