Which of the following is the unit for intensity in ultrasound?

The unit for intensity in ultrasound is watts per square centimeter (W/cm²). Intensity, which refers to the power of the ultrasound wave per unit area, is a critical parameter in ultrasound imaging because it affects the quality of the images obtained and the safety of the procedure for the patient.

Using W/cm² as the unit allows for a clear representation of how much power is being exerted over a specific area. This is especially important in ultrasound because the intensity influences the interaction of the sound waves with biological tissues, including their ability to penetrate, reflect, and transmit through different mediums.

While there are other units mentioned—like W/m², which measures intensity over square meters, and J/m², which relates more to energy density rather than the continuous power needed for ultrasound—neither is the standard in medical ultrasound practice. Similarly, Pa/cm² (Pascals per square centimeter) is a unit of pressure, not directly applicable to the measurement of intensity in this context. Thus, W/cm² is the most relevant and widely accepted unit for describing ultrasound intensity.