A procedure for removing the blurring in microdensitometric analysis.

The bone width of the femur and fibula was measured by three techniques, osteometry, radiogrametry and microdensitometry, in six adult crab-eating monkeys (Macaca fascicularis). The measurement was taken five times at midshaft and at proximal and distal epiphyseal sites in each bone. Based on the paired t test, the bone width obtained microdensitometrically was significantly greater than that measured by other techniques (p less than 0.05). It seems to be one of the causative factors for these differences that X-rays produce a blurring zone around the shadow of an original object on the film. The blurring is not visually identified, but it can be distinguished from the real image in microdensitometric analysis. A procedure was devised for removing errors by the blurring in microdensitometric measurement of the bone width. According to its algorithm, a program was assembled using a personal computer.