Methods of optoacoustic diagnostics of biological tissues

Laser optoacoustic diagnostics is based on thermoelastic excitation of ultrasonic signals in a medium due to absorption of pulsed laser radiation. The pressure profile of such an ultrasonic (or optoacoustic) signal contains information on the distribution of heat sources in the medium. Hence, detection of optoacoustic signals reveals the distribution of absorbing inhomogeneities in the medium under investigation. Application of optoacoustic diagnostics in various fields of biology and medicine (e.g., for visualization of blood vessels and malignant tumors) has been much discussed in literature. Research in optoacoustic diagnostics is mainly concerned with the development of systems for optoacoustic signal detection, methods of signal processing, and algorithms for optoacoustic image reconstruction. The present paper reviews the latest achievements in this field of research and discusses its prospects.