Mineral content of cortical bone measured by computed tomography.

A method for the computed tomographic measurement of bone calcium in the cortex of the femur or tibia is described. A calibration standard is scanned concurrently with the bones being measured. The standard contains high and low density references arranged so that the errors due to beam hardening and partial volume effects are minimized or cancelled. Repositioning errors are insignificant because of the uniformity of the cortical bone being measured. Results from cases of osteoporosis, osteomalacia, and others are discussed. The method probably combines the best elements of accuracy and precision that are necessary for useful measurement. It can be used with existing whole body scanners.