Photoacoustic characterization of bone physico-chemical information

This paper introduces a novel method, multi-wavelength photoacoustic time-frequency spectral analysis (MWPA-TFSA), to evaluate bone chemical composition and microstructure simultaneously. The method is based on optical absorption spectra and photoacoustic effects of biological macromolecules. It aims to provide a noninvasive and non-radiative bone assessment technique. The MWPA-TFSA method analyzes photoacoustic signals at different wavelengths to investigate changes in bone minerals and lipids. It also uses the time-frequency spectrum at the optical absorption wavelength of bone marrow to determine the size of bone marrow clusters, which relates to trabecular thickness. The study used rabbit models to compare osteoporotic bones with normal bones. The results showed that osteoporotic bones had decreased bone mineral density (BMD), more lipids, and wider trabecular separation with larger marrow clusters, which aligns with other standard diagnostic methods.

• 1
  Osteoporotic bones exhibit a lower content ratio of hemoglobin (Hb) to lipid compared to normal bones, as indicated by the lower energy ratio of E760/E930 in MWPA measurements.
• 2
  Osteoporotic bones show a lower content ratio of bone mineral and Hb to lipid compared to normal bones, as indicated by the lower energy ratio of E700/E930 in MWPA measurements.
• 3
  Osteoporotic bones have a higher slope of normalized energy, indicating lower propagating attenuation due to lower BMD, which is consistent with DEXA results.