What does an increase in pulse repetition frequency (PRF) typically indicate?

An increase in pulse repetition frequency (PRF) is associated with a shorter listening time. This is because PRF refers to the number of ultrasound pulses transmitted per second. When PRF is increased, the time that the system spends listening for the echoes returning from the tissue is reduced. Each pulse requires a certain amount of time to be sent out, and if these pulses are sent more frequently, the listening period must shorten to accommodate the higher rate of transmission.

This shorter listening time can affect the maximum depth from which echo signals can be received, as there is less time to collect echoes from deeper structures before the next pulse is emitted. It allows for quicker imaging but can also lead to potential issues such as range ambiguity, where echoes from deeper structures may overlap with signals from shallower depths.