Osteoporosis: Clinical assessment with quantitative MR imaging in diagnosis

PURPOSE: To determine if the magnetic resonance (MR) imaging effective transverse relaxation rate (R2*) of trabecular bone marrow is lowered in osteoporosis. MATERIALS AND METHODS: R2* was measured in 146 women. Control subjects (n = 77; mean age, 46.6 years) had high mean spinal bone mineral densities (BMDs) and no vertebral deformities. Patients with spinal osteoporosis (n = 59; mean age, 59.7 years) had at least one thoracic vertebral deformity and/or low BMDs. RESULTS: R2* was lower in patients for L-2 through L-5 (P < .001). Average R2* of L-3 through L-5 (R2*(av)) was the best discriminator (64.79 sec^-1 ± 1.18 [standard error] for control subjects vs 53.39 sec^-1 ± 1.24 for patients; P < .0001). R2*(av) decreased with age in control subjects. The difference in R2*(av) in a subset of 38 age-matched pairs of patients and control subjects was 8.25 sec^-1 (P < .0001). Subjects with deformities had lower 52*(av) than did control subjects (52.3 sec^-1 ± 1.6 vs 62.5 sec^-1 ± 1.1, P < .0001). R2*(av) was correlated with mean BMD (r = .54, P < .0001). CONCLUSION: Patients with osteoporosis have lower R2*s in vertebral marrow.