Pulse repetition frequency (PRF) is measured in which units?

Pulse repetition frequency (PRF) is measured in which units?

• A. Per Minute
• B. Microseconds
• C. MHz
• D. Per Second

Answer: (D)

PRF measures how many ultrasound pulses are emitted each second, so the natural unit is a rate per time. That means pulses per second, i.e., hertz. Microseconds would describe the time between pulses (the pulse repetition interval), not the rate. MHz describes the transducer’s carrier frequency, not how often pulses are emitted. Per minute would be a valid rate, but the standard unit used is per second. Therefore, Per Second is the correct unit.

PRF measures how many ultrasound pulses are emitted each second, so the natural unit is a rate per time. That means pulses per second, i.e., hertz. Microseconds would describe the time between pulses (the pulse repetition interval), not the rate. MHz describes the transducer’s carrier frequency, not how often pulses are emitted. Per minute would be a valid rate, but the standard unit used is per second. Therefore, Per Second is the correct unit.