Correlation of bone mineral density with MRI T2* values in quantitative analysis of lumbar osteoporosis.

ABSTRACT

We found that the MRI T2* value is moderately negatively correlated with the bone mineral density assessed with quantitative computed tomography in evaluating osteoporosis in postmenopausal women and may have some potential in assessing severity of lumbar osteoporosis for scientific research. PURPOSE: To investigate the T2* quantitative measurement in magnetic resonance imaging (MRI) and its correlation with the bone mineral density (BMD) values evaluated with quantitative computed tomography (QCT) in women with postmenopausal lumbar vertebrae osteoporosis. MATERIALS AND METHODS: Eighty-seven postmenopausal women were enrolled who had MRI scanning with T1WI, T2WI, and T2* mapping sequences and QCT evaluation of BMD. The T2* value and the BMD were assessed in lumbar vertebral bodies 2-4. Based on the BMD values, the patients were divided into three groups normal, osteopenia, and osteoporosis. RESULTS: The inter- and intra-observer intraclass correlation coefficients (ICCs) for T2* were 0.91 (0.87-0.94, 95% CI) and 0.93 (0.88-0.95, 95% CI), respectively. The inter- and intra-observer ICCs for the BMD value were 0.89 (0.83-0.92, 95% CI) and 0.91 (0.86-0.93, 95% CI), respectively. The differences of the T2* values and BMD among the three groups were statistically significant (P < 0.05). The BMD value was greater in the normal group (145.02 ± 18.94 mg/cm3) than the other two groups (97.90 ± 16.18 mg/cm3 for osteopenia and 59.09 ± 18.71 mg/cm3 for osteoporosis). The normal group had a significantly (P < 0.05) smaller T2* value than the other two groups (8.39 ± 4.17 ms in the normal group versus 12.25 ± 3.36 ms in the osteopenia or 15.54 ± 4.9 ms in the osteoporosis). A significant (P < 0.05) difference also existed in the T2* value between the osteopenia and the osteoporosis groups. The correlations of the T2* values with BMD values were significantly (P < 0.05) negative after adjusting for age (r = - 0.33, - 0.45, and - 0.51 for normal, osteopenia, and osteoporosis, respectively). CONCLUSION: The MRI T2*value is moderately negatively correlated with the bone mineral density assessed with quantitative computed tomography in evaluating osteoporosis in postmenopausal women and may have some potential in assessing severity of lumbar osteoporosis for scientific research.