Non-contrast Magnetic Resonance Imaging for Diagnosis and Monitoring of Vestibular Schwannomas: A Systematic Review and Meta-analysis

Objective: This study aimed to evaluate the diagnostic accuracy of high-resolution T2-weighted magnetic resonance imaging (T2wi) in terms of detecting vestibular schwannoma compared with gadolinium-enhanced T1-weighted MRI (GdT1wi). Data Sources: Five databases (PubMed, SCOPUS, Embase, the Web of Science, and the Cochrane database). Data Selection: Two authors independently searched five databases up to January 2019 on diagnosis of vestibular schwannomas via T2wi. Data Extraction: In the included studies, tumor diameters reported using T2wi were compared with those revealed by GdT1wi and correlation coefficients were calculated. Data on true-positives, true-negatives, false-positives, and false-negatives were extracted from the relevant articles. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Inter-rater agreement among different observers and intra-rater agreement among different measurements made by a single observer was assessed. Data Synthesis: Outcomes subjected to analysis included diagnostic accuracy (the diagnostic odds ratio); summary receiver operating characteristic curve and area under the curve values. The summary intra-class correlation coefficient was used for various random-effects models. The quality of each study was analyzed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Conclusions: T2wi performed without the use of a contrast agent is a highly accurate diagnostic and monitor tool compared with GdT1wi and also demonstrated high reliability. However, further studies are required to confirm the results of this study.