Usefulness of quantitative computed tomography for measurement of vertebral bone mineral density in osteoporosis

The present studies were undertaken to elucidate the usefullnes of the qantitative computed tomography in mesurement of bone densites of lumbar spine in senile and postmenopausal osteoporosis. The CT-numbers of the spongiosum of the second lumbar spine and K2HPO4 solusion phantom were mesured in the same series scanning, and the bone densities were displayed as concentrations of K2HPO4 solution (QCT-value). The QCT-values are well related with the bone densities which were mesured with single photon absorptiometor (Norland-Cameron) at one third and one sixth distal ends of radiuses. The QCT-values decrease with aging, and the decrement in female is more remarkable than that in male. The decrement of QCT-value starts at in 3rd decade of their life time. It is defferent from the conclusions those were obtained with the measurement of clavicular cortex index, or single photon absorptiometor. The QCT-values of the patients with lumbargo are lower than those of the patients without lumbargo. The QCT-values of the patients without compression fructure in lumbar spine are higher than those of the patients with compression fructure, but the number of the sites of compression fructures in lumbar spine appears to have no effect on the QCT-values. The QCT-values of postmenopausal osteoporosis were improved by the administration of calcium and 1α-OHVit. D3 (0.5 μg/day. for a year). (author)