Ex-vivo and First-in-Man Study of Bone Pathologies Using Low-Cost and Compact Dual-Wavelength Photoacoustic System

Osteoporosis is a major public health problem worldwide. Identifying and treating patients at risk of fracture, but who have not yet sustained a fracture, can substantially reduce the fracture incidence. Available diagnostic methods, which measure bone mass density, include either dual energy X-ray absorptiometry or a Quantitative Ultrasound (QUS). However, these methods suffer from a low sensitivity to functional changes in the bone which are of great importance for early diagnosis. To address this issue, presented here is a low-cost and compact dual-wavelength Photoacoustic (PA) system. Ex-vivo experiments demonstrate the sensitivity of the PA system to the functional changes and a quantitative measure of the marrow’s blood/fat ratio is proposed. Turning to human trails, a dual-modality system combining both PA and QUS was developed and used for demonstrating the repeatability and accuracy of the PA method, in healthy human volunteers. Such method can expand and complement QUS as well as to open avenues for bedside early detection and monitoring of disease progression and response to therapies.