Optic neuritis: MR imaging with combined fat- and water-suppression techniques.

PURPOSE: To examine the benefits of combined fat- and water-suppressed T2-weighted magnetic resonance (MR) images in the diagnosis of optic neuritis.

MATERIALS AND METHODS: MR imaging was performed with a 1.5-T unit in five healthy volunteers and 18 patients (21 nerves). All patients had abnormalities of visual evoked potentials and fulfilled the clinical criteria for the diagnosis of optic neuritis. Imaging was performed within 4 weeks of diagnosis (n = 12) or between 3 and 6 months after diagnosis (n = 6). Coronal images were obtained throughout the course of the optic nerve with use of three sequences: (a) short inversion time inversion recovery with fast spin-echo (SE) acquisition, (b) selective partial inversion-recovery (SPIR) prepared T2-weighted fast SE acquisition, and (c) SPIR-fluid-attenuated inversion recovery (FLAIR) with fast SE acquisition.

RESULTS: Neuritic segments were demonstrated in all 21 symptomatic nerves. The extent of neuritic involvement (number of images showing abnormality) was significantly greater with the SPIR-FLAIR sequence (P < .01). The contrast ratio between neuritic optic nerve and orbital fat, normal nerve, and cerebral spinal fluid was significantly greater with SPIR-FLAIR than with the other sequences (P < .001). SPIR-FLAIR images also improved demonstration of optic nerve atrophy in chronic neuritis when compared with the other sequences.

CONCLUSION: The SPIR-FLAIR sequence offers important advantages over current methods in the demonstration of optic neuritis.