Four-Hour Delayed Gadolinium-Enhanced 3D-FLAIR MR Imaging Highlights Intralabyrinthine Micro-Schwannomas.

ABSTRACT

OBJECTIVE: To demonstrate the clinical significance of 4-hour delayed gadolinium-enhanced three-dimensional fluid-attenuated inversion recovery (delayed 3D-FLAIR) in patients with intralabyrinthine schwannoma (ILS). PATIENTS Three patients who were clinically diagnosed with ILS. INTERVENTIONS: All patients underwent audiological examinations and magnetic resonance imaging (MRI) scans. The MR-protocol included axial MR cisternography, immediate gadolinium-enhanced T1-weighted sequence, and heavily T2-weighted 3D-FLAIR prior to and 4 hours after the intravenous administration of gadolinium contrast medium. MAIN OUTCOME MEASURES: All MR images were visually inspected. RESULTS: In all three patients with ILS, delayed 3D-FLAIR MRI demonstrated a strong signal of cochlear fluid surrounding the tumor, which highlighted a tumor region that lacked signals. CONCLUSIONS: Delayed 3D-FLAIR MRI may serve as a novel diagnostic tool for the early detection of intralabyrinthine micro-schwannoma. The findings also shed light on the pathophysiology of ILS.