Abstract
Photoacoustic imaging is a unique modality that overcomes the resolution and depth limitations of
optical imaging of tissues while maintaining relatively high contrast. In this article, we review the
biomedical applications of photoacoustic imaging for cancer diagnosis. Representative endogenous
photoabsorbers include melanin and hemoglobin, whereas exogenous photoabsorbers include dyes,
metal nanoparticles, and other constructs that absorb strongly in the near-infrared band of the optical
spectrum and generate strong photoacoustic responses. These photoabsorbers, which can be specifi cally
targeted to molecules or cells, have been coupled with photoacoustic imaging for preclinical and clinical
applications including detection of cancer cells, sentinel lymph nodes, micrometastases, and monitoring
of angiogenesis. Overall, photoacoustic imaging has significant potential to assist in diagnosis,
therapeutic planning, and monitoring of treatment outcome for cancers and other pathologies.
