The callosal-septal interface lesion in multiple sclerosis: effect of sequence and imaging plane.

We examined the effect of imaging plane and sequence on the demonstration of lesions at the callosal-septal interface (CSI) by magnetic resonance imaging in 20 patients with known multiple sclerosis. Variable-echo-(VE) T2- and proton density (PD) weighted images were performed in coronal axial and sagittal planes. Sagittal gradient echo (GE) T2- and PD-weighted images were also performed. Lesions at the CSI were seen in all patients and were all demonstrated on both sagittal and coronal VE images. Sagittal PD-weighted GE images were slightly less sensitive but showed good overall agreement with sagittal VE. Axial VE and sagittal T2-weighted GE images demonstrated CSI lesions poorly.