Nonconventional approaches to ultrasonic assessment of skeletal system

Abstract

Conventional bone ultrasonometry is based on the transmission mode measurement of the linear acoustic parameters of bone (speed of sound and broadband attenuation). It is a well-established technique specifically for osteoporosis diagnostics though it is highly limited in its applications. It cannot be used for the assessment of the hip bone which is the most important area in characterization of the skeletal system and can hardly be used in pediatric applications, particularly in neonatology, for the assessment of newborns and premature and low-birth-weight infants skeletal systems, which became especially vital during the last few decades. There are several new ideas on acoustic assessment of the skeletal sites hardly accessible by the conventional bone ultrasonometry and on principles of the acoustic characterization of bone quality, fracture risk evaluation, and monitoring of therapeutic interventions. New approaches are based on the use of the ultrasound radiation pressure for the remote generation of acoustic waves in bones, on the use of various modes of guided acoustic waves having a propagation speed dependent on both the elasticity modulus and the bone thickness, on the use of geometrical dispersion of sound velocity for bone characterization, and the use of principles of nonlinear acoustic spectroscopy for remote bone testing. [Work supported by NIH.]