Automatic detection of asymmetry in skin tumors.

Asymmetry, a critical feature in the diagnosis of malignant melanoma, is analyzed using a new algorithm to find a major axis of asymmetry and calculate the degree of asymmetry of the tumor outline. The algorithm provides a new objective definition of asymmetry. A dermatologist classified 86 tumors as symmetric or asymmetric. Borders of tumors were found either manually or automatically using a radial search method. With either method, asymmetry determination by the asymmetry algorithm agreed with the dermatologist's determination of asymmetry in about 93% of cases.