ACUTE SUBARACHNOID HEMORRHAGE - MR-IMAGING WITH FLUID-ATTENUATED INVERSION-RECOVERY PULSE SEQUENCES

PURPOSE: To evaluate the usefulness of fluid-attenuated inversion reco very (FLAIR) magnetic resonance (MR) imaging sequences in the detectio n of acute subarachnoid hemorrhage (SAH). MATERIALS AND METHODS: MR im aging with FLAIR sequences was performed with a 0.5-T superconducting unit in 20 patients (aged 30-72 years) with acute SAH due to a rupture d aneurysm and in 27 control subjects (aged 32-72 years). FLAIR images were obtained 2 hours to 2 days after ictus. Findings were evaluated and compared with computed tomographic (CT) findings. RESULTS: In all patients, acute SAH was clearly demonstrated as an area with signal in tensity that was high relative to that of the normal cerebrospinal flu id and surrounding brain parenchyma at FLAIR imaging. This sequence wa s especially useful in demonstration of acute SAH in the posterior fos sa, which was difficult to show at CT because of beam-hardening artifa cts. In a double-blind comparison, no FLAIR images acquired in control subjects were confused with those acquired in patients. CONCLUSION: F LAIR sequences reliably provide diagnostic images in patients with acu te SAH.