A COMPUTERIZED METHOD FOR DETERMINATION OF MICROVASCULAR DENSITY

Currently accepted stereological methods for vascular density measurem ents involve manual counting of labeled vessels with a grid image over lay and determination of vessel-grid intersections. This method both i s tedious and may be prone to error; therefore, our laboratory has dev eloped a method for computer-automated determination of microvascular density using digital image processing techniques. An image of the mic rovasculature is acquired using computer videomicroscopy. The image is processed in three general steps, involving (1) background correction , (2) thresholding of the gray level image to create a binary image, a nd (3) processing of the binary image using erosion, dilation, and ske letonization algorithms. Testing of this procedure was performed on 32 8 typical images of skeletal muscle tissue sections taken from the hin dlimb of Sprague-Dawley rats and quantitated by both traditional measu res and our new computer method. Results from this comparison reveal t hat the automated vessel counting is highly correlated (r(2) = 0.71) a nd decreased analysis time from 15 min/image to 30 sec/image when comp ared with manual counting methods. Our computer-based method also appe ars to be superior to the traditional method due to the unbiased and n onsubjective nature of determining vessel-grid intersections. (C) 1995 Academic Press. Inc.