As imaging depth increases, PRP changes in which direction?

As imaging depth increases, PRP changes in which direction?

• A. Increases
• B. Decreases
• C. Fluctuates
• D. Stays the same

Answer: (A)

PRP is the time between the start of one transmitted pulse and the start of the next. As imaging depth increases, the echoes from the deepest region take longer to return, so the system must wait longer between pulses to avoid missing those far echoes. That makes PRP grow with depth. Since PRF is the reciprocal of PRP, deeper imaging also means a lower PRF. So the direction is increases. The other options don’t fit because shorter intervals wouldn’t capture deeper echoes, a constant interval ignores the travel-time delay, and a fluctuating interval wouldn’t reliably image at greater depths.

PRP is the time between the start of one transmitted pulse and the start of the next. As imaging depth increases, the echoes from the deepest region take longer to return, so the system must wait longer between pulses to avoid missing those far echoes. That makes PRP grow with depth. Since PRF is the reciprocal of PRP, deeper imaging also means a lower PRF. So the direction is increases. The other options don’t fit because shorter intervals wouldn’t capture deeper echoes, a constant interval ignores the travel-time delay, and a fluctuating interval wouldn’t reliably image at greater depths.