The error due to fat inhomogeneity in lumbar spine bone mineral measurements.

Bone mineral mass measurements using dual photon absorptiometry rely on the assumption that fat thickness is constant within the region scanned by the photon beam. This assumption has been tested using both single and multiple slices from archived CT scans. In 26 patients, the difference in fat content between the bone and baseline measurement sites, the fat deviation, was found to vary from -2.7 to 18.7%. The median fat deviation was 4.4% …