Steady-State Free Precession MRI Imaging as a Screening Evaluation for Vestibular Schwannoma

Abstract

Objectives:

(1) Compare noncontrast steady-state free precession (SSFP, also called FIESTA, CISS, and bFFE) magnetic-resonance imaging (MRI) to contrast-enhanced full sequence MRI for initial evaluation of retrocochlear pathology. (2) Assess the sensitivity and specificity of SSFP alone versus complete contrast-enhanced MRI as the gold standard.

Methods:

Retrospective review of a tertiary care center radiology imaging database from 2006 to present was performed. Based on statistical power analysis, 50 studies with identified vestibular schwannomas and 53 studies with normal internal auditory canal (IAC) findings were included. Four expert reviewers performed blinded, randomized evaluation of non-contrast SSFP sequence and contrast-enhanced MRI studies to evaluate for retrocochlear pathology. MRI reports from the original studies were used as the gold standard. Using XLSTAT™ statistical software, data were analyzed using a 2-sided z-test of one proportion for each reviewer’s sensitivity and specificity against a 95% standard. Inter-reader reliability was determined using kappa analysis.

Results:

Four reviewers, including 2 neuroradiologists, one neurotologist, and one neurosurgeon had 100% specificity. Average sensitivity was 96% (range, 94-100%). There was no statistically significant difference when each sensitivity and specificity was compared against a 95% standard or in results between reviewers. Tumors eccentric in the IAC or with significant artifact were more likely to not be identified.

Conclusions:

Noncontrast SSFP sequence MRI may be an effective initial study to perform for evaluation of vestibular schwannomas. Given its shorter duration (5 minutes versus 25 minutes) as well as the noncontrast method, clear advantages exist for this method.