Microscopic elastic properties

Abstract

Several high frequency ultrasound techniques have been developed during the last decade with the intention to assess elastic properties of bone at the tissue level. In this chapter three major principles are described with exemplary measurements in the frequency range from 50MHz to 1.2GHz. The methods are compared and their application potentials and limitations are discussed with respect to the hierarchical structure of cortical bone. While highly focused transducers with frequencies between 50 and 200MHz are suitable for the assessment of microscale elastic properties, frequencies in the gigahertz range are dedicated to the investigation of the anisotropic lamellar bone structure. The relations between tissue mineralization, acoustic properties and anisotropic elastic coefficients at the micro- and nanoscales will be summarized.