Cavitation from ultrasound in tissue layers can result from which intensity level?

• A. Low intensity
• B. Higher than therapeutic intensity
• C. Therapeutic intensity
• D. High intensity

Answer: (B)

Cavitation is a mechanical effect that happens when the acoustic pressure from ultrasound becomes large enough to make tiny gas nuclei or dissolved gases form bubbles, which can then oscillate and even violently collapse. This requires a higher acoustic pressure than those used in normal diagnostic or safe, standard therapeutic settings.

In practice, diagnostic ultrasound and approved therapeutic ranges are chosen to stay below the threshold that would reliably produce cavitation. When you use a level of intensity higher than what’s considered therapeutic, the pressure amplitudes increase enough to nucleate and drive cavitation in tissue layers. That’s why cavitation is associated with intensities exceeding the therapeutic range rather than with the typical low or therapeutic levels.

So, cavitation from ultrasound in tissue layers can result from higher than therapeutic intensity, because only at those elevated energy levels is the acoustic pressure sufficient to form and collapse microbubbles.