What measurement unit is used for Broadband Ultrasound Attenuation (BUA)?

• A. Decibel/megahertz (dB/MHz)
• B. Microseconds (μs)
• C. Joules (J)
• D. Hertz (Hz)

Answer: (A)

Broadband Ultrasound Attenuation (BUA) is measured in decibels per megahertz (dB/MHz). This unit reflects the attenuation of ultrasound waves as they pass through bone tissue, providing insight into the bone's density and quality. The measurement helps in assessing bone strength and can contribute to the evaluation of fracture risk.

The use of decibels indicates a logarithmic scale, which is useful for gauging the relative intensity of the ultrasound signal that has been absorbed by the bone. By standardizing the measurement per megahertz, it allows for comparisons across different frequencies of ultrasound, crucial for accurate assessments in bone densitometry.

In contrast, other options like microseconds pertain to time measurement, joules relate to energy, and hertz is a frequency unit, none of which provide the necessary context for assessing ultrasound attenuation specifically in the context of BUA. Therefore, the choice of decibel per megahertz is specifically tailored to capture the nuances of how ultrasound interacts with bone structure.