In what order do the temporal intensities rank from largest to smallest?

The correct ranking of temporal intensities from largest to smallest is based on the definitions and typical values for each intensity type involved in ultrasound physics.

Im, or the maximum intensity, is generally the highest because it represents the peak intensity of the beam, capturing the highest amplitude and energy delivery at a given moment.

Ipa, or the pulse average intensity, is following next in magnitude. Ipa reflects the average intensity over the duration of the pulse, which is still substantial but generally lower than the maximum instantaneous value that Im represents.

Itp, or temporal peak intensity, can also rank higher than average values because it specifically accounts for the peak intensity during the pulse duration, often capturing a portion of the peak that is not accounted for in average intensities.

Lastly, Ita, or temporal average intensity, is the smallest, because it accounts for the overall average intensity throughout the entire pulse cycle, including the time the ultrasound beam is off, leading to a lower value compared to the other types.

Thus, the order — Itp, Im, Ipa, Ita — reflects the decreasing intensity values as the temporal characteristics of the ultrasound beam are considered. This understanding is critical in the context of ultrasound physics as it lays the foundational knowledge essential for safe and effective