Osteoporosis: clinical assessment with quantitative MR imaging in diagnosis.

Abstract

To determine if the magnetic resonance (MR) imaging effective transverse relaxation rate (R2*) of trabecular bone marrow is lowered in osteoporosis. 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. 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). Patients with osteoporosis have lower R2*s in vertebral marrow.