Role of MRI in meningiomas: with and without gadopentetate.

Seventeen patients (15 newly diagnosed and two recurrent) with meningiomas were studied by magnetic resonance imaging (MRI) operating with 0.3, 0.5, and 1.5 Tesla magnets. In four patients gadopentetate dimeglumine was administered, following a noncontrast scan. In all the patients the tumors were isointense with the cortex at short relaxation and echo times (TR and TE) and became hyperintense with the increase in TR and TE on 0.3, 0.5, and 1.5 Tesla magnet systems. MRI correlated well with angiography in the detection of sagittal sinus thrombosis, and delineated tumor from edema as in computed tomography. Elimination of bony artifacts made detection of posterior fossa tumors easier with MR scanning. Gadopentetate dimeglumine shortened the scan time, displaying small tumors as well as sagittal sinus involvement to advantage. In these respects, we believe MRI is more effective than computed tomography in the diagnosis and management of meningiomas.