Chapter 10: Back of Book

The lateral resolution of an ultrasound system is primarily determined by

• width of the sound pulse

• length of the ultrasound pulse

• duration of the sound pulse

• none of the above

Two ultrasound systems produce acoustic pulses. One pulse is 0.4 μsec in duration and the other is 0.2 μsec. Which pulse will most likely provide the best lateral resolution?

• 0.4 μsec

• 0.2 μsec

• they are the same

• cannot be determined

Answer explanation

pulse duration is unrelated to lateral resolution

True or False

The pulse duration doesn't profoundly influence the lateral resolution

• True

• False

Two ultrasound systems have near zone lengths of 8 cm. At the focus, System G's lateral resolution is 3.0 mm, whereas System P's is 5.0 mm. Which system will produce higher quality pictures at their foci?

• System P

• System G

• both will be of similar quality

True or False

When using standard ultrasonic imaging instrumentation, the lateral resolution has a higher numerical value than the axial resolution.

• True

• False

The lateral resolution of an ultrasound system is 4mm. Two structures are separated by 3 mm and lie side by side in relation to the sound beam's main axis. What will most likely appear on the system's display?

• two weak echoes, 4 mm apart

• two bright echoes, 3 mm apart

• one echo

• two bright echoes, 7 mm apart

Answer explanation

Lateral resolution when structures are closer together and it will blur together

True or False

When using an instrument typical of today's imaging devices, a higher frequency transducer is likely to mildly improve the system's lateral resolution.

• True

• False

True or False

When using an instrument typical of today's diagnostic imaging devices, a higher frequency transducer is likely to improve the axial resolution.

• True

• False

What will lower the value of an ultrasound system's lateral resolution?

• decrease the # of cycles in the pulse

• increase the effective damping material

• increase the pulse repetition period

• use an acoustic lens

Which of the following techniques is internal focusing?

• lens

• curved crystal

• electronic