Knowing the width of the bone and the
amount of attenuation that occurs to the
sound waves as they pass through the bone,
the bone density can be calculated. This
measurement is known as broadband
ultrasonic attenuation or BUA and is
expressed as decibels per centimeter per
megahertz. Other measurements and
determinations made by ultrasonic systems
include bone stiffness BMD. As with all
ultrasound probes, some coupling medium
is required to ensure sound penetration of
and below the skin. Ultrasonometry systems
either use ultrasonic gel or immerse the
transducers and the patient’s foot in a water
bath to achieve this coupling