Analysis using histograms of muscle CT images in patients with Duchenne muscular dystrophy.

We showed that the shape of the thigh CT value histogram, which was reflecting muscle and fat, changed with the disease progression in a patient with Duchenne muscular dystrophy, and this shape of the histogram will employ a new analytical method. CT images of the middle part of the thigh were acquired in a patient with Duchenne muscular dystrophy once a year from 6 to 11 years of age. Regions apparently corresponding to subcutaneous fat, bone and bone marrow were manually excluded, and the CT values were calculated to prepare histograms. His motor disability was also evaluated employing Vignos functional rating scale. A single peak was noted in the muscle CT value range in the histogram at the youngest age. The muscle-to-fat ratio in muscle decreased with the worsening of his disease disability level and the peak of the histogram shifted from the muscle to the fat CT value.