Quantitative Evaluation of Male Pattern Baldness by Image Analysis

Several methods for quantitative evaluation of male pattern baldness have been reported. Recently, the progress of computer and image analysis technique are remarkable. Some investigators have attempted to apply these techniques to evaluation of male pattern baldness. We have also developed two image analysis systems to study human hair growth. One is ‘hair diameter measuring system’, and the other is a novel system to measure the anagen/telogen ratio.By using hair diameter measuring system, 15 subjects were measured their hair diameter over one year. In the measurement of the hair growth rate exactly, we used animmersion photomethod and compared 6 normal subiects and 6 subjects with male pattern baldness. Close-up photographs were applied to the measurement of the anagen ratio and the growing hair-area. The term ‘hair-area’ was defined as the proportion of hair to the total area in the binary image. Three parameters, the hair growth rate, the anagen ratio, and the growing hair-area, were obtained by our novel system.The average hair diameter decreased and the distribution pattern of hair diameter remarkably changed with progression of male pattern baldness. Furthermore, the hair diameter showed a straight line decrease over one year. In male pattern baldness the growth rate of anagen hair was 20% slower than in normal subjects. We also investigated a seasonal change in anagen ratio in 15 subjects, It was shown that the anagen ratio had a peak in February. The growing hair-area was a novel parameter, which was calculated with comparing two photographs. We measured the growing hair-area with 52 sets of close-up photographs that the anagen ratio was measured by visual observation. The growing hair area decreased with decline of anagen ratio.We consider that our image analysis systems are useful to evaluate male pattern baldness and reliable for testing the effects of hair growth agents.