In vivo biopsy by photoacousticUS based tissue characterization

Our recent research has demonstrated that the frequency domain power distribution of radio-frequency (RF) photoacoustic (PA) signals contains the microscopic information of the optically absorbing materials in the sample. In this research, we were seeking for methods of systematically analyzing the PA measurement from biological tissues and the feasibility of evaluating tissue chemical and microstructural features for potential tissue characterization. By performing PA scan over a broad spectrum covering the optical fingerprints of specific relevant chemical components, and then transforming the radio-frequency signals into the frequency domain, a 2D spectrogram, namely physio-chemical spectrogram (PCS) can be generated. The PCS contains rich diagnostic information allowing quantification of not only contents but also histological microfeatures of various chemical components in tissue. Comprehensive analysis of PCS, namely photoacoustic physio-chemical analysis (PAPCA), could reveal the histopathology information in tissue and hold the potential to achieve comprehensive and accurate tissue characterization.