Magnetic resonance imaging of acoustic neuromas.

Ten patients with neurosensory hearing loss and computed tomographic (CT) evidence of acoustic neuromas were evaluated with magnetic resonance imaging (MRI). Tumors ranged in size from 0.8 to 3.7 cm. With the use of spin echo pulse sequences, all tumors were identified by MRI and appeared as masses with signal intensities greater than that of cerebrospinal fluid and equal to or greater than that of brain stem. Two patients who previously had undergone operation for acoustic neuromas were evaluated with MRI. In one patient with CT evidence of tumor recurrence, the lesion could not be identified by MRI. MRI holds promise of becoming a primary diagnostic modality for the evaluation of acoustic neuromas.