In vivo photoacoustic lipid imaging in mice using the second near-infrared window.

Photoacoustic imaging has emerged as a promising technique to improve preclinical and clinical imaging by providing users with label-free optical contrast of tissue. Here, we present a proof-of-concept study for noninvasive in vivo murine lipid imaging using 1210 nm light to investigate differences in periaortic fat among mice of different gender, genotypes, and maturation. Acquired lipid signals suggest that adult male apoE(-/-) mice have greater periaortic fat accumulation compared to adolescent males, apoE(-/-) females, and wild-type mice. These results demonstrate the potential of photoacoustic tomography for studying vascular pathophysiology and improving the diagnosis of lipid-based diseases.