When the depth of view is shallow, PRF is _____.

When the depth of view is shallow, PRF is _____.

• A. High
• B. Medium
• C. Low
• D. Very High

Answer: (A)

When the imaging depth is shallow, echoes return very quickly. PRF is how often the system sends out pulses, and it must be high enough to fit multiple pulses into the short round-trip time of the shallow depth without overlapping echoes from consecutive pulses. Because the farthest echoes come back so fast, you can fire pulses more frequently, giving a high PRF. If you image deeper, echoes take longer to return, so PRF must be reduced to avoid confusing echoes from different pulses. So, shallow depth of view corresponds to a high PRF.

When the imaging depth is shallow, echoes return very quickly. PRF is how often the system sends out pulses, and it must be high enough to fit multiple pulses into the short round-trip time of the shallow depth without overlapping echoes from consecutive pulses. Because the farthest echoes come back so fast, you can fire pulses more frequently, giving a high PRF. If you image deeper, echoes take longer to return, so PRF must be reduced to avoid confusing echoes from different pulses. So, shallow depth of view corresponds to a high PRF.