Advanced imaging techniques, which are noninvasive and nondestructive, can provide structural information about bone beyond simple bone densitometry. As the mechanical competence of trabecular bone is a function of its apparent density and D distribution, assessment of D trabecular structural characteristics may improve our ability to understand the pathophysiology of osteoporosis, to test the efficacy of pharmaceutical intervention, and to estimate bone biomechanical properties. We studied ovariectomy-induced osteopenia in rats with various treatments. Micro-CT is also useful for studying osteoporosis in mice and phenotypes of mice with gene manipulation. Micro-CT can quantify osteogenesis in mouse Ilizarov leg-lengthening procedures, osteoconduction in rat cranial defect models, and structural changes in arthritic rabbits, rats, and mice. Micro-CT can reproducibly quantify D microarchitecture of new bone formation inside the pores of titanium prosthesis implants is rabbits. In clinical studies, we evaluated longitudinal changes in iliac crests in premenopausal and postmenopausal women. Paired bone biopsies from postmenopausal women with osteoporotic fracture shows that D trabecular microstructure deteriorates in the iliac crest of postmenopausal osteoporotic women without active treatment. Three-dimensional microstructural parameters can predict fracture. Treatment of PTH in postmenopausal women with osteoporosis significantly improved trabecular morphology with a shift toward a more plate-like structure, increased trabecular connectivity, and increased cortical thickness. Paired bone biopsy specimens from the iliac crest in postmenopausal women with osteoporosis before and after beginning estrogen replacement therapy demonstrated in post-treatment biopsies a significant change in the ratio of plates to rods. High-resolution MR and μMR have received considerable attention both as research tools and potential clinical tools for assessment of osteoporosis. It has been used in studying human specimens or animal models of osteoporosis with various treatment strategies.MR microscopy has been shown to capable of differentiating trabecular structure in the distal radius and the calcaneus in postmenopausal women with or without os- teoporotic fracture. It has been used in studying human specimens or animals models of osteoporosis with various treatment strategies. A high field MR study show that ovariectomy in ewes induces deterioration of trabecular microstructure and biomechanical property of the femoral neck. These changes are prevented by calcitonin in a dose-dependent manner. Univariate analysis and multivariate stepwise regression analysis indicate that microarchitecture of trabecular bone contributes significantly to its biomechanical characteristics, independent of BMD measured in the femoral neck. Combination of trabecular microstructure with BMD improves prediction of bone quality.
