Bone Composition Diagnostics: Photoacoustics Versus Ultrasound

• DOI: 10.1007/s10765-014-1701-6
• Publication Date: 2014-08-11T10:25:47Z
• Authors: Lifeng Yang; Bahman Lashkari; Andreas Mandelis; Joel W. Y. Tan
• Keywords: 0103 physical sciences; 01 natural sciences

Ultrasound (US) backscatter from bones depends on the mechanical properties and the microstructure of the interrogated bone. On the other hand, photoacoustics (PA) is sensitive to optical properties of tissue and can detect composition variation. Therefore, PA can provide complementary information about bone health and integrity. In this work, a comparative study of US backscattering and PA back-propagating signals from animal trabecular bones was performed. Both methods were applied using a linear frequency modulation chirp and matched filtering. A 2.2 MHz ultrasonic transducer was employed to detect both signals. The use of the frequency domain facilitates spectral analysis. The variation of signals shows that in addition to sensitivity to mineral changes, PA exhibits sensitivity to changes in the organic part of the bone. It is, therefore, concluded that the combination of both modalities can provide complementary detailed information on bone health than either method separately. In addition, comparison of PA and US depthwise images shows the higher penetration of US. Surface scan images exhibit very weak correlation between US and PA which could be caused by the different signal generation origins in mechanical versus optical properties, respectively.