Evaluation of calcium concentration in bones from CT scans

Fresh cadaveric lumbar vertebrae from 28 subjects were obtained at autopsies and then analyzed by CT scans. An average CT number, calibrated against water and representing the relative x-ray attenuation coefficient of cancellous bone of each vertebra, was obtained. Calcium concentrations in milligrams per cubic centimeter for each vertebral specimen, calculated by physical methods, were plotted against the average CT numbers. The results suggest a linear relationship between the CT numbers and the calcium content of bone.