In pulsed ultrasound, which statement is true?

In pulsed ultrasound, which statement is true?

• A. Anything below 100%
• B. 100%
• C. 50%
• D. 0%

Answer: (A)

The main idea here is the duty cycle of pulsed ultrasound. In pulsed mode, energy is delivered in bursts with off times between them, so the duty cycle is less than 100%. That means the average intensity is lower than with continuous (on all the time) ultrasound. Therefore the statement that anything below 100% describes pulsed ultrasound is true. The other options describe either continuous exposure (100%), a specific duty cycle that isn’t guaranteed for all settings (50%), or no energy at all (0%), which doesn’t fit the concept of pulsed ultrasound.

The main idea here is the duty cycle of pulsed ultrasound. In pulsed mode, energy is delivered in bursts with off times between them, so the duty cycle is less than 100%. That means the average intensity is lower than with continuous (on all the time) ultrasound. Therefore the statement that anything below 100% describes pulsed ultrasound is true. The other options describe either continuous exposure (100%), a specific duty cycle that isn’t guaranteed for all settings (50%), or no energy at all (0%), which doesn’t fit the concept of pulsed ultrasound.