Pulsed ultrasound is characterized by which of the following?

Pulsed ultrasound is characterized by which of the following?

• A. Anything below 100% duty cycle
• B. 100% duty cycle
• C. No energy emission
• D. Constant energy output

Answer: (A)

Pulsed ultrasound is defined by energy being emitted in bursts with off time between them. The key idea is the duty cycle, which is the fraction of time the energy is on during one cycle. Any duty cycle below 100% means there are off periods, which creates a pulsed pattern rather than continuous emission. If the duty cycle were 100%, energy would be emitted continuously—the waveform would be continuous rather than pulsed. If there’s no energy emission, that corresponds to a 0% duty cycle, which isn’t pulsed. Constant energy output describes continuous emission as well. So, anything below 100% duty cycle best characterizes pulsed ultrasound.

Pulsed ultrasound is defined by energy being emitted in bursts with off time between them. The key idea is the duty cycle, which is the fraction of time the energy is on during one cycle. Any duty cycle below 100% means there are off periods, which creates a pulsed pattern rather than continuous emission. If the duty cycle were 100%, energy would be emitted continuously—the waveform would be continuous rather than pulsed. If there’s no energy emission, that corresponds to a 0% duty cycle, which isn’t pulsed. Constant energy output describes continuous emission as well. So, anything below 100% duty cycle best characterizes pulsed ultrasound.