Cancer is a classic example of a disease that must be diagnosed early to be effectively treated or cured. Responsible for one in every four American deaths, it is the second leading cause of death in the US and a major health problem worldwide. Technological advancement, increased cancer awareness, and an aging, increasingly susceptible population have spurred the development of a host of early detection modalities, including magnetic resonance imaging, ultrasound, positron emission tomography, x-ray imaging, and optical—or biophotonic—imaging. Yet current diagnostic imaging technologies are too complex and expensive for widespread use, expose patients to hazardous radiation, or aren’t sensitive enough to detect nascent tumors.
In the past decade, photoacoustic (PA) imaging, in which subsurface tissue is excited with light and then imaged with ultrasound, has emerged as a promising complement to those technologies. It lacks the hazardous high magnetic fields of MRI and the ionizing radiation of x-ray imaging...
