Comparison of vertebral and peripheral mineral losses in disuse osteoporosis in monkeys.

Vertebral mineral loss (measured by computed tomography) was compared to peripheral mineral loss (measured by photon absorptiometry) in immobilized monkeys. Significantly greater loss was found in axial cancallous bone than in peripheral cortical bone. The accuracy of vertebral CT measurements in one animal was determined using direct chemical analysis of excised vertebrae. Results indicate that mineral changes may be detected earlier in the vertebrae by CT than in peripheral bone using photon absorptiometric techniques.