The present invention provides an osteoporosis diagnosis aiding apparatus
that utilizes a panoramic radiograph. A digitalized image of the
panoramic radiograph enters a personal computer (S210). The cortical bone
at the lower edge of the mandibular molar in the panoramic radiograph is
specified with a mouse to make that part a target of examination (S220).
This extracted image is subjected to the following image processing. (1)
Subject the image to median filtering so as to reduce noises throughout
that image. (2) Find a skeleton constituted by micro-structural elements
(S230). (3) Extract only components parallel to the tilt of the lower
edge of the mandible (S240). (4) Binarize the image using Otsu's linear
discrimination method, for example (S250). The binarized lines are then
classified into three groups according to size, and can be determined as
a risk of osteoporosis in a case where there is more than just a single
line classified in the largest line group aside from the smallest line
group.