Which term describes the overall energy carried by the ultrasound waves per unit area?

Which term describes the overall energy carried by the ultrasound waves per unit area?

• A. Average intensity of sound waves
• B. Spatial average density
• C. Duty cycle
• D. Effective radiating area

Answer: (A)

The concept being tested is how much energy the ultrasound delivers to tissue per unit area, which is described by intensity. Intensity measures the energy crossing a given area each second, and using the term average intensity reflects the typical exposure when the ultrasound is delivered in pulses. This makes it the best descriptor for the overall energy delivered per unit area. The other terms don’t fit as well: duty cycle is about how much of the time the beam is on during pulsing, not the energy per area; the effective radiating area refers to the size of the transducer’s emitting surface; and spatial density isn’t the standard term used for describing energy per area in this context.

The concept being tested is how much energy the ultrasound delivers to tissue per unit area, which is described by intensity. Intensity measures the energy crossing a given area each second, and using the term average intensity reflects the typical exposure when the ultrasound is delivered in pulses. This makes it the best descriptor for the overall energy delivered per unit area.

The other terms don’t fit as well: duty cycle is about how much of the time the beam is on during pulsing, not the energy per area; the effective radiating area refers to the size of the transducer’s emitting surface; and spatial density isn’t the standard term used for describing energy per area in this context.