Three-dimensional tomographic reconstruction of simulated and in vivo sub-surface chromophores

Infrared tomography (IRT) is a non-contact technique to determine the size and position of sub-surface chromophores, using a recorded time sequence of infrared emission images following pulsed laser irradiation. A potential application for IRT is the laser treatment of port wine stains (PWS), where the clinician needs diagnostic information to select optimal irradiation parameters. In this paper, Re report recent progress using IRT to determine diagnostic information regarding blood vessels comprising a PWS. In our simulations, a three-dimensional skin model containing an epidermis and blood vessels is used, from which a time sequence of infrared emission images is calculated. Size and position of sub-surface chromophores computed from the time sequence of infrared emission images by application of an inversion algorithm are very close to actual values. For in vivo studies, the chick chorioallantoic membrane is an ideal PWS model. Size and position of a subsurface blood vessel are correctly predicted by application of an inversion algorithm, given a recorded time sequence of infrared emission images.