Unstable cavitation is best described as gas bubbles that do what under ultrasound exposure?

Unstable cavitation is best described as gas bubbles that do what under ultrasound exposure?

• A. Expand and then violently collapse
• B. Remain stable and oscillate slowly
• C. Only compress under high pressure
• D. Never occur during therapy

Answer: (A)

Unstable cavitation, or inertial cavitation, happens when gas bubbles grow during the negative-pressure phase of the ultrasound wave and then violently collapse when the pressure turns positive. That rapid collapse releases strong local forces, producing shock waves and microjets. This description—bubbles expanding and then violently imploding under ultrasound exposure—best fits the concept. In contrast, bubbles that merely oscillate in size without violent collapse represent stable cavitation, and the idea of bubbles only compressing under high pressure or never occurring under therapy doesn’t capture the explosive collapse that characterizes unstable cavitation.

Unstable cavitation, or inertial cavitation, happens when gas bubbles grow during the negative-pressure phase of the ultrasound wave and then violently collapse when the pressure turns positive. That rapid collapse releases strong local forces, producing shock waves and microjets. This description—bubbles expanding and then violently imploding under ultrasound exposure—best fits the concept. In contrast, bubbles that merely oscillate in size without violent collapse represent stable cavitation, and the idea of bubbles only compressing under high pressure or never occurring under therapy doesn’t capture the explosive collapse that characterizes unstable cavitation.