In-vitro comparison of volumetric and areal bone mineral density measurements between ultrasound transit time spectroscopy and microcomputed tomography

Abstract Quantitative ultrasound is a scientifically and clinically accepted diagnostic technique for assessing and predicting osteoporotic fracture risk. However, it does not provide a direct measurement of areal bone mineral density, and hence cannot implement the World Health Organization T score criteria for osteoporosis and osteopenia. In this study, we developed a novel method based on the concept of ultrasound transit time spectroscopy (UTTS) to derive volumetric and areal bone mineral densities. Through-transmission ultrasound signals at 1 MHz were used to measure 12 human femoral head in-vitro bone samples. Volumetric and areal bone mineral densities were calculated from the derived and corrected ultrasound transit time spectra. A linear regression model was used to compare the results obtained by ultrasound with those by microcomputed tomography. This analysis showed coefficients of determination (R2) of 86% and 80% for volumetric and areal bone mineral density, respectively. Given that quantitative ultrasound is nonionizing, low cost, and portable, we propose that directly derived areal bone mineral density obtained using ultrasound transit time spectroscopy, UTTS-aBMD, may be utilized for osteoporosis assessment, implementing the WHO T score criteria.