DIGITIZED NAILFOLD CAPILLAROSCOPY

An image processing system was developed to quantify the morphometry o f nailfold capillaroscopy. Image acquisition was performed with a macr ophotographic technique, and images are digitized using a video camera and an image processing system. After an image segmentation, the micr ocomputer determines in an interactively defined window, the following parameters: capillary loop width and length, capillary surface area, distance from the tip of the capillary loop to the dermal edge, distan ce between two adjacent capillaries. Other parameters can be computed from these: linear density, density and dispersion index of the distan ce between two adjacent capillaries (variation coefficient). A validat ion study, comparing 20 capillary fields from healthy subjects and 19 capillary fields with <<SD-pattern>>, provided from patients with syst emic sclerosis or dermatomyositis, reveals significant differences of all these parameters between the two groups, consistent with the liter ature. This study also isolates two parameters which are the best pred ictors of the <<SD-pattern>>: the mean capillary surface and the capil lary density (capillaries/mm2). The morphometric parameters obtained t hrough this system are suitable for evaluation of microangiopathy and should be evaluated for diagnosis and follow-up of vascular acrosyndro ms, systemic sclerosis, Raynaud phenomenon and allied conditions in cl inical conditions.