The quantitative diagnostic capability of routine MR imaging and diffusion-weighted imaging in osteoporosis patients

To determine the quantitative diagnostic capability of magnetic resonance imaging (MRI), compared to dual-energy X-ray absorptiometry (DEXA), for osteoporosis.

Eight male volunteers and eight patients underwent both DEXA and MRI. Results were obtained from each subject's L2 to L4, for a total of 48 lumbar vertebrae. Based on their bone mineral density (BMD) acquired from DEXA, the vertebrae were classified as follows: normal (n=28), osteopenic (n=0), and osteoporotic (n=20). All MR examinations were performed on a 1.5-T scanner to obtain T1-weighted imaging (T1WI), fat-suppression T2-weighted imaging (FS-T2WI), and diffusion-weighted imaging (DWI). These quantitative MR parameters were determined: T1WI and FS-T2WI signal-to-noise ratios and DWI apparent diffusion coefficient values. To determine the diagnostic capability of MRI as an osteoporosis indicator, MR parameters were assessed statistically.

All MR parameters significantly correlated with BMD (T1WI: r=-0.64, FS-T2WI: r=-0.36, DWI: r=-0.29), with significant differences among normal and osteoporotic vertebrae (P<.05). By receiver operating characteristic analysis, the area under the curve of T1WI was significantly higher than others (P<.05). When adapted as feasible threshold values, sensitivity, specificity, and accuracy of T1WI were 95.0% (19/20), 92.9% (26/28), and 93.8% (45/48), respectively.

Routine MRI, in particular T1WI, had a potential for the assessment of osteoporosis.