Identifying novel clinical surrogates to assess the strength of human bones: ex vivo and clinical finding

Speaker:Jean-Gabriel Minonzio (UPMC)

Time and Date: 15:00-17:00, Oct. 27, 2015

Place: Room 521, Physics Building, Handan Campus

 

 

Abstract

Structural decay of bone is not fully assessed by current X-ray methods, and there is an unmet need in identifying women at risk of fracture who should receive a treatment. The last decade has seen the emergence of ultrasound axial transmission (AT) techniques to assess cortical bone, known for its key role in the mechanical strength of bone. Recent AT techniques exploit the multimode waveguide response of long bones. Applied to long bones such as the radius or tibia, guided waves based approaches would be expected to provide estimates of important bone quality factors, such as cortical thickness and porosity, which cannot easily be captured by X-ray densitometry techniques (DXA). The potential of ultrasound guided waves to yield estimate of these properties and to predict bone strength is investigated in both ex vivo radii and in a pilot clinical study.

Measurements were performed at the distal radius using our AT prototype device (Azalée, Paris, France) consisting in a multi-transmitter multi-receiver probe. In addition to the fundamental flexural wave (A0 mode) velocity, the cortical thickness and the apparent porosity were estimated by fitting a homogenized free plate model to the experimental dispersion curves measured in the 0.5-1.5 MHz frequency bandwidth. Present ex vivo findings reflect the feasibility of guided wave measurements to provide estimates of cortical thickness and porosity on ex vivo human long bones. The clinical preliminary results suggest the potential of ultrasonic guided modes to predict fracture risk in postmenopausal women. These studies are currently being completed by inclusion of a larger number of specimens and patients in order to assess the method reliability and accuracy.

 

 

Biography

Jean-Gabriel Minonzio was born in Dijon, France, in 1978. He received the B.S. degree in engineering physics from the Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI), Paris, France, in 2003. He obtained the M.S. and Ph.D. degrees in physical acoustics from the University Denis Diderot, Paris, in 2003 and 2006, respectively. His research interests included time reversal and scattering of acoustical and electromagnetic waves, array signal processing, underwater acoustics, and target characterization. He currently works on elastic guided waves in cortical bone at the Laboratoire d’Imagerie Biomédicale (LIB), Université Pierre et Marie Curie (UPMC), in Paris.