PRP is unrelated to which quantity?

• A. Period
• B. Depth of view
• C. Frequency
• D. Amplitude

Answer: (A)

PRP is the time between successive ultrasound pulses. It is determined by how deep you’re imaging (longer travel time for echoes from deeper structures, so you wait longer before the next pulse) and by the speed of sound in tissue, and it is the reciprocal of the pulse repetition frequency. The period in question here refers to the duration of one cycle of the transmitted wave, which is set by the transducer frequency (period = 1/f). That cycle duration is a separate time scale from the interval between pulses, so PRP is not determined by the wave’s period. In other words, PRP changes with depth and frame timing, while the wave period depends on frequency. Therefore PRP is unrelated to the period.