Sagittal Cobb angle measurements in scoliosis using total spine MR imaging

Aim: A newly developed MR procedure allows imaging of the whole spine in coronal and sagittal planes. We studied the use of total spine MR imaging in measuring sagittal Cobb angles in scoliosis. Method: 64 patients with idiopathic scoliosis (mean age 18.1 years, 35 thoracic, 20 double major, and 9 lumbar curves) and 27 patients without scoliosis were consecutively examined. The MR images were acquired in the supine position. The sagittal Cobb angles were measured between T4-T12 and between T12-L.5. Results: For the group of the thoracic and double major scoliosis the mean sagittal Cobb angle (T4-T12) was 13 degrees and for the group without scoliosis 23 degrees, which was a significant difference (p<0.01, Mann Whitney-U-test). There was a negative correlation between the sagittal Cobb angles (T4-T12) and the lateral, thoracic curves. The mean sagittal Cobb angle (T12-L5) of the group with lumbar and double major curves was 35 degrees, which was not a significant difference when compared to 37 degrees of the non-scoliotic group. Conclusion: Using total spine MR imaging the lordotic aspect of the thoracic deformation in scoliosis can be reliably measured. Because of the absent radiation exposure the sagittal MR reconstructions could be used as an additional imaging in monitoring scoliosis.