Ultrasonic scattering models for cancellous bone

Quantitative ultrasound (QUS) in transmission has played a growing role in t he assessment of osteoporosis. It is generally accepted that transmission QUS represents a surrogate marker for bone mineral density. Scattering techniques may be useful for the assessment of bone micro- architecture, an independent predictor of fracture risk. We will review recent experimental data (in vitro and in vivo) as well as theoretical modeling of ultrasound scattering by cancellous bone. Good agreement between experimental data and predictions has been reported for the frequency-dependent backscatter coefficient. In addition, in vivo data showed that the ultrasound backscatter was significantly associated with fracture risk.