Photoacoustic tomography (PAT) is an emerging imaging modality that combines the most compelling features of optics and ultrasound, providing both high optical contrast and high ultrasound resolution at depth. PAT's unique properties make it superior to other modalities in generating information-rich structural and functional images in multiple critical disease areas, including applications within cancer, cardiovascular disease, dermatology, women's and men's health, and inflammation. PAT can generate powerful images based on inherent soft-tissue contrast without external contrast agents, and is also extremely well-suited for use with existing and specialized photoacoustic contrast agents. The equipment is inexpensive, safe, and well understood, making the platform ideal for clinical use.

Photoacoustic signals are induced by pulsed laser illumination. When laser energy is absorbed by biological tissues, the resulting very minimal heating of the tissues generates ultrasonic waves. The waves can be detected by an ultrasonic transducer and then used to create an image of the optical absorption distribution inside the tissues. Different soft tissue types in the body differentially absorb laser light of different wavelengths, providing high inherent contrast.