A PRELIMINARY ASSESSMENT OF LASER-DOPPLER PERFUSION IMAGING IN HUMAN SKIN USING THE TUBERCULIN REACTION AS A MODEL

Laser Doppler imaging is a new development in the field of laser Doppl er flowmetry. We were recently loaned the Lisca laser Doppler perfusio n imager (LDI) Manufactured by Lisca Development, Linkoping, Sweden fo r assessment against other methods for assessment of skin perfusion. I n order to evaluate the device, it was applied to imaging flux changes induced in human skin during the tuberculin reaction. Flux values wer e compared directly with those from conventional lightguide laser Dopp ler flowmetry, and parameters measured using two other methods for ass essment of tissue perfusion, dynamic thermographic imaging and tissue spectrophotometry. The results showed very good correlations between t he various methods. In addition, the LDI showed that very large differ ences in flux values (up to 5 V) could be found within distances of on ly 2 mm during the tuberculin reaction and that focal centres of low f lux values surrounded by higher values ('craters') could be found not only at the centre, but elsewhere in the lesion. The LDI enables rapid non-invasive detailed analysis of blood flow patterns in skin and cor relates well with other methods for measuring skin perfusion. Its use to examine heterogeneity of microvascular blood flow patterns may lead to further understanding of the local mechanisms for regulation of ox ygen supply to tissue.