Measures at the location where intensity is maximum, averaged over the transmit time (pulse duration).

Measures at the location where intensity is maximum, averaged over the transmit time (pulse duration).

• A. Isptp
• B. Ita
• C. Ipa
• D. Isppa

Answer: (D)

This measures the spatial-peak pulse-average intensity: the strength of the ultrasound at the location where the instantaneous intensity is highest, averaged over the actual transmit time (the pulse duration). In pulsed beams, this means you average only during the on-time of each pulse, at the hotspot location. This is distinct from the temporal-average measures that include off-times between pulses (which lowers the average), and from the temporal-peak measure that looks at the single highest instant within the pulse. So the description fits the SPPA quantity: intensity at the peak location, averaged over the pulse duration.

This measures the spatial-peak pulse-average intensity: the strength of the ultrasound at the location where the instantaneous intensity is highest, averaged over the actual transmit time (the pulse duration). In pulsed beams, this means you average only during the on-time of each pulse, at the hotspot location.

This is distinct from the temporal-average measures that include off-times between pulses (which lowers the average), and from the temporal-peak measure that looks at the single highest instant within the pulse. So the description fits the SPPA quantity: intensity at the peak location, averaged over the pulse duration.