Question

Which parameter is decreased by the ultrasound machine to evade the possibility of range ambiguity when the imaging depth is increased?

a. Number of scan lines
b. Pulse repetition frequency (PRF)
c. Pulse repetition period (PRP)
d. Persistence

Answer 1

To prevent range ambiguity in deeper ultrasound imaging, the Pulse Repetition Frequency (PRF) is decreased, which increases the Pulse Repetition Period (PRP).

Step-by-step explanation:

To avoid the possibility of range ambiguity when the imaging depth is increased in an ultrasound machine, the parameter that is decreased is the Pulse Repetition Frequency (PRF). Range ambiguity occurs when the next pulse is sent before the echo of the previous pulse is received, which can happen if the object is very deep and the time for the echo to return is longer. To ensure echoes from one pulse are received before the next pulse is emitted, the PRF is decreased, thereby increasing the Pulse Repetition Period (PRP) and making certain that echoes from deeper within the body are not confused with subsequent pulses.