Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published November 10, 2010 | public
Book Section - Chapter

Photoacoustic Tomography


Photoacoustic tomography (PAT) refers to imaging that is based on the photoacoustic effect. Although the photoacoustic effect as a physical phenomenon was first reported on by Alexander Graham Bell in 1880 [1], PAT as an imaging technology was developed only after the advent of ultrasonic transducers, computers, and lasers [2–31]. A review on biomedical photoacoustics is available [32]. The motivation for PAT is to combine optical-absorption contrast with ultrasonic spatial resolution for deep imaging in the optical quasi-diffusive or diffusive regime. In PAT, the tissue is irradiated by usually a short-pulsed laser beam to achieve a thermal and acoustic impulse response (Fig. 19.1). Locally absorbed light is converted into heat, which is further converted to a pressure rise via thermo-elastic expansion. The initial pressure rise – determined by the local optical absorption coefficient (μ_â), fluence (ψ) and other thermal and mechanical properties – propagates as an ultrasonic wave, which is referred to as a photoacoustic wave.

Additional Information

© 2011 Springer Science+Business Media B.V. The author thanks H. Zhang and K. Maslov for providing unpublished Fig. 19.4. This work was sponsored by National Institutes of Health grants R01 EB000712 and R01 NS46214.

Additional details

August 19, 2023
October 25, 2023