The method of segmenting a lesion in an image according to the present invention includes the steps of: obtaining an image of a region of interest from an image of a lesion; adjusting the contrast of the obtained image of the region of interest such that the contrast changes according to the distance from the center of the region of interest; removing noise from the image whose contrast is adjusted; and separating the region of the lesion from the noise-removed image. In the step of adjusting the contrast, the image is adjusted such that the contrast is increased as it goes away from the center of the region of interest, and thus it is possible to segment the lesion while maintaining the original shape of the lesion, thereby reliably segmenting the lesion even in the case where the inside of the lesion is not uniform.