Photoacoustic Spectrum Analysis for Soft Tissues

Biomedical photoacoustics has shown great potential for precise medical diagnosis because it can provide structural, physiological/pathological characteristics, and metabolic information of biological tissues noninvasively in vivo. Photoacoustic imaging has made great breakthroughs in many preclinical studies, including microvascular imaging, blood oxygen detection, and tumor detection. However, compared with photoacoustic imaging, the photoacoustic spectrum can provide more information, such as the rich molecular information in the optical spectrum and the rich microstructural information in the ultrasonic spectrum, which is closely related to the disease evolution process. Recently, photoacoustic spectrum analysis (PASA) has demonstrated the ability to quantitatively extract physicochemical information from biological tissues to distinguish between normal and diseased tissues, especially for classifying, grading, and staging cancer tissue, making it one of the most promising methods for noninvasive, accurate diagnosis of clinical diseases. In this chapter, we introduce the methods of PASA for the diagnosis of soft tissue diseases.