Pulse repetition period and imaging depth are ______ related.

Pulse repetition period and imaging depth are ______ related.

• A. Not related
• B. Directly related
• C. Inversely related
• D. Randomly related

Answer: (B)

Pulse repetition period is the time between the start of one ultrasound pulse and the start of the next. When you image deeper, echoes from the deepest points take longer to return, so the system must wait longer before emitting the next pulse. That longer listening time increases the interval between pulses, meaning the pulse repetition period grows with imaging depth. So they are directly related. (Note that the reciprocal relationship with pulse repetition frequency also fits: deeper imaging lowers PRF because PRF = 1/PRP.) Not related, inverse, or random do not fit this physical behavior, since deeper imaging requires more time between pulses.

Pulse repetition period is the time between the start of one ultrasound pulse and the start of the next. When you image deeper, echoes from the deepest points take longer to return, so the system must wait longer before emitting the next pulse. That longer listening time increases the interval between pulses, meaning the pulse repetition period grows with imaging depth. So they are directly related. (Note that the reciprocal relationship with pulse repetition frequency also fits: deeper imaging lowers PRF because PRF = 1/PRP.) Not related, inverse, or random do not fit this physical behavior, since deeper imaging requires more time between pulses.