Continuous output in ultrasound is associated with what effect?

Continuous output in ultrasound is associated with what effect?

• A. Thermal
• B. Nonthermal
• C. Both
• D. None

Answer: (A)

Continuous output means ultrasound energy is transmitted without interruption, so the duty cycle is effectively 100%. This constant energy delivery causes sustained absorption by tissues, which raises tissue temperature—the thermal effect. Nonthermal effects, like cavitation and microstreaming, are most often linked to pulsed ultrasound where off times permit mechanical interactions without significant heating. When ultrasound is continuous, the heating tendency dominates, especially at higher intensities or longer exposure.

Continuous output means ultrasound energy is transmitted without interruption, so the duty cycle is effectively 100%. This constant energy delivery causes sustained absorption by tissues, which raises tissue temperature—the thermal effect. Nonthermal effects, like cavitation and microstreaming, are most often linked to pulsed ultrasound where off times permit mechanical interactions without significant heating. When ultrasound is continuous, the heating tendency dominates, especially at higher intensities or longer exposure.