ABSTRACT
Photoacoustic (PA) tomography (PAT), also referred to as optoacoustic tomography, is an emerging biomedical imaging method based on the PA ežect (Xu and Wang 2006, Li and Wang 2009, Oraevsky and Karabutov 2003). ™e PA ežect was reported by Alexander Graham Bell in 1880 (Bell 1880), and refers to the generation of acoustic waves by substances being illuminated by electromagnetic (EM) waves of varying power. ™e PA ežect results from the variational thermal expansion within the material as it absorbs the EM radiative energy. Since the ability of EM absorption re¦ects a material’s characteristics, much physical and chemical information can be revealed by studying PA signals. Historically, the PA ežect was of little research interest for a long time, but the invention of laser, an adequate PA illumination source, changed matters drastically. Now, various
detection methods based on PA ežect have been widely implemented in physics, chemistry, biology, engineering, and medicine (Rosencwaig 1980, Gusev et al. 1993).
