In ultrasound physics, Pulse Repetition Frequency (PRF) is a critical parameter referring to the number of ultrasound pulses emitted by the transducer per second. Measured in Hertz (Hz) or kilohertz (kHz), PRF directly influences the maximum depth from which echoes can be accurately received before the next pulse is sent. A higher PRF allows for faster imaging but reduces the maximum imaging depth, while a lower PRF enables deeper penetration at the cost of temporal resolution.
Understanding PRF is crucial for optimizing medical ultrasound imaging. It directly impacts the potential for artifacts like range ambiguity and aliasing, especially in Doppler studies where it determines the Nyquist limit—the maximum velocity that can be accurately measured. Sonographers adjust PRF to balance image depth, frame rate, and Doppler sensitivity, ensuring clear visualization and accurate diagnostic information for various medical applications.