MR of hemorrhagic acoustic neuromas.

The magnetic resonance (MR) appearance of hemorrhagic acoustic neuromas has not previously been reported. Four patients with surgically proven acoustic neuromas containing spontaneous hemorrhage were preoperatively evaluated with MR imaging. All patients presented with new onset of symptoms and three had subarachnoid hemorrhage. Signal changes on T1- and T2-weighted spin echo sequences were characteristic for acute, subacute and chronic intraparenchymal hemorrhage. Recognition of hemorrhagic changes on MR is important since more rapid surgical intervention is required in this patient subgroup.