Non-Contrast MR T2-Weighted Imaging Is as Accurate as Contrast-Enhanced T1-Weighted Imaging in the Detection of Meningioma Growth

<b>Background/Objectives</b>: Asymptomatic meningiomas require frequent follow-up using MR imaging, with the standard of care being contrast-enhanced T1-weighted imaging (CE-T1WI) with Gadolinium-Based Contrast Agents (GBCAs). Limiting GBCA exposure reduces the environmental impact and limits possible gadolinium deposition in the brain. Therefore, the research objective was investigating the diagnostic accuracy of T2WI for evaluating significant meningioma growth (≥10% per year), using the CE-T1WI as reference standard. <b>Methods</b>: A total of 99 asymptomatic patients with the radiological diagnosis of meningioma and a minimum follow-up period of 11 months were retrospectively identified. Patients were scanned with various scanners in multiple hospitals. The maximum tumor diameter was measured in the transverse plane. Tumor growth was calculated in changes in millimeters and converted to percentages in the longest tumor diameter in the transverse plane. A paired-sample <i>t</i>-test was used to compare tumor growth on T2WI to CE-T1WI. The diagnostic accuracy of T2WI was determined by calculation of sensitivity, specificity, and positive and negative predictive values. <b>Results</b>: Mean follow-up time was 1.9 years. Significant tumor growth was found in 16 patients using T2WI, compared to 10 patients using CE-T1WI, which was not statistically significant. T2WI had a sensitivity of 80%, specificity of 90%, a positive predictive value of 47%, and negative predictive value of 98% for prediction of significant meningioma growth. <b>Conclusions</b>: T2WI was not inferior to CE-T1WI in the detection of significant tumor growth in asymptomatic meningioma and therefore can be used in follow-up to reduce gadolinium exposure.