Abstract
Our working hypothesis is that a dual-wavelength Nd:YAG laser, emitting simultaneously at 1064 and 532 nm, may induce stronger heating of PWS blood vessels relative to the epidermis than the customary KTP laser, due to conversion of hemoglobin to met-hemoglobin in the target blood vessels and the associated increase in NIR absorption. We apply pulsed photothermal radiometry to determine temperature depth profiles induced in PWS lesions by a dual-wavelength laser at sub-therapeutic radiant exposures. The results indicate no effect at 1 ms pulse duration and low radiant exposures (1-2 J/cm2). Increased radiant exposure (3-4 J/cm2) and extended pulse duration (20-25 ms) result in increased energy deposition. In addition, two PWS lesions and one healthy skin site were irradiated at incrementally increasing radiant exposures, up to 9 J/cm2. Analysis of the laser-induced temperature profiles clearly revealed irreversible changes of tissue properties. Formation of met-hemoglobin and consequent increase of IR absorption was however not reliably detected.
© 2007 SPIE
PDF ArticleMore Like This
Liudmila Astafyeva, Georgy Zheltov, and Wolf-Dieter Schmidt
5142_169 European Conference on Biomedical Optics (ECBO) 2003
Liudmila Astafyeva, Georgy Zheltov, and Wolf-Dieter Schmidt
TuH47 European Conference on Biomedical Optics (ECBO) 2005
T. E. Milner, B. Anvari, J. S. Nelson, B. S. Tanenbaum, and L. O. Svaasand
OPTTM.269 Advances in Optical Imaging and Photon Migration (BIOMED) 1994