Sodium-23 imaging of supratentorial lesions at 4.0 T.

In 27 patients with low and high grade gliomas (n = 17), meningiomas (n = 4), and other supratentorial tumors and lesions (n = 6), the results of sodium-23 MR imaging with high spatial resolution were compared to CT and proton MRI. The Na MR studies were performed with a 4.0-T whole-body MR system and an isotropic 3D-Flash sequence (TR 70 ms, TE 11 ms), which depicts the long T2 component of sodium. All patients tolerated the sodium study at 4.0 T well. The sodium images revealed almost all lesions, but the resolution was inferior to that of the reference methods. Two small meningiomas did not show up at all in the sodium study. Furthermore in one case small hemorrhages and calcifications within one of the tumors could not be found. Sodium imaging of the long T2 component did not provide any additional information regarding the histology, grading, size, and differentiation of the tumor from the surrounding edema which had not already been provided by CT or H MRI.