US Physics 391-420

You are imaging a 3D dataset that has anisotropic resolution. What does this mean?

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?

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?

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?

You have obtained an ultrasound image that demonstrates refraction of the sound beam. This artifact might be manifested as:

Which of the following conditions will result in aliasing of the Doppler frequency shift using continuous-wave Doppler?

You obtained a 3D sweep in an axial plane and are viewing it in a multiplanar display. What orthogonal planes will be displayed?

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?

Which technology would be most helpful to obtain accurate anatomic volume measurements?

You may observe a mirror image artifact with which imaging mode?

Which of the following artifacts may result in both an axial and lateral displacement of a reflector on the ultrasound image?

Which imaging technique may increase visualization of the reflections from blood flow on the real-time ultrasound image?

While scanning a curved structure, you notice shadowing at the lateral edges of the structure. What is required for this artifact to occur?

What artifact is being described in the previous question?

The range equation describes the relationship between:

Requirements of magnetic field tracking for 3D reconstruction include:

Which of the following artifacts is the result of reverberation?

Which of the following artifacts commonly results in echoes filling in the lumen of small vessels?

Propagation speed error results in which sonographic appearance?

When you select harmonic imaging, which artifact is less likely to be observed?

When you select compound imaging, which artifact is less likely to be observed?

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

This image exhibits banding. This is a result of:

What imaging artifact is much worse on the left phantom image compared to the right phantom image?

What type of transducer will you improve the artifact demonstrated in the previous question?

This image was obtained with a linear array transducer that employs phasing to steer the beam. What artifact do the arrows point to?

What can be done to reduce the presence of the artifact seen in the previous question?

Complete destructive interference of echo reflections will affect the display in the following way:

You are observing a sonographic artifact based on the interference patterns of scattered echoes. What artifact are you imaging?

Which of the following will improve the artifact you are imaging in the previous question?