High-Resolution T2-Weighted Imaging for Surveillance in Postoperative Vestibular Schwannoma: Equivalence with Contrast-Enhanced T1WI for Measurement and Surveillance of Residual Tumor

A and B, A 66-year-old-man with a history of retrosigmoid-approach resection of a left vestibular schwannoma. Axial Gd-T1WI (A) and HR-T2WI (B) demonstrate postprocedural changes, including encephalomalacia and gliosis in the left brachium pontis and lateral cerebellar hemisphere. A large-volume tumor is detectable on both the Gd-T1WI and HR-T2WI, as indicated by the yellow arrow. C and D, A 51-year-old woman with a history of retrosigmoid-approach resection of a left vestibular schwannoma. Axial Gd-T1WI (C) and HR-T2WI (D) demonstrate residual disease within the left cerebellopontine angle cistern, detectable on both Gd-T1WI and HR-T2WI, as indicated by the yellow arrow. E and F, A 60-year-old man with a history of retrosigmoid-approach resection of a right vestibular schwannoma. Axial Gd-T1WI (E) and HR-T2WI (F) demonstrate residual disease in the right internal auditory canal, as indicated by the yellow arrow.