Photoacoustic diagnosis of burns in rats: two-dimensional photoacoustic imaging of burned tissue

We previously reported that for rat burn models, deep dermal :burns and deep burns can be well differentiated by the propagation time of the photoacoustic signals originated from the blood in the healthy skin tissue under the damaged tissue. However; the diagnosis was based on point measurement In the wound, and therefore site-dependent information on the injuries was not obtained; such information is very important for diagnosis. of extended burns. In the present study, we scanned a photoacoustic detector on the wound and constructed two-dimensional (2-D) images of the blood-originated photoacoustic signals for superficial dermal burns (SDB); deep dermal burns (DDB), deep burns (DB); and healthy skins (control) in rats. For each burn, site-dependent variation of the signal was observed; the variation probably reflects the non-uniform distribution of blood vessels in the skin tissue. In spite of the variation, clear differentiation was obtained between SDB, DDB, and DB from the images. The images were constructed. as a function of post burn time. Temporal signal variation will also be presented.