Rationale and Objectives. The ability of three-dimensional micro-computed tomography (3D-μCT) to detect changes in a rat model of disuse osteoporosis was evaluated and compared with two reference techniques: dual x-ray absorptiometry (DEXA) for bone mass, and bone histomorphometry (BHM) for bone mass and trabecular micro-architecture. Methods. Forty-two rats were divided into controls or were hindlimb unloaded for 7, 13, and 23 days. DEXA bone mineral density measurements were performed on right tibiae. Then, after plastic embedding, bone volume (BV/TV) and trabecular (Tb)-derived parameters of trabecular bone architecture (Tb Th, thickness; Tb N, number) were measured with BHM. 3D-μCT measurements of BV/TV, Tb Th, and Tb N were carried out on left tibiae. Results. Unloaded rats lost bone in a time-dependent manner. DEXA and 3D-μCT detected bone loss earlier than BHM. The decreases in Tb Th and Tb N were observed at day 13 only with 3D-μCT (P < 0.05 and P < 0.01, respectively). All bone mass and architectural parameters measured with the three techniques correlated significantly (0.59, 0.89, P < 0.001), except Tb Th. Conclusions. 3D-μCT is a valid technique for bone mass and micro-architecture measurements in this rat model of disuse osteoporosis.
- Bone histology-unloading
- Bone mineral density-immobilization
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging