PMC4898225_01
71-year-old man with vestibular schwannoma. Contrast-enhanced MRI of the brain and IACs. Axial precontrast T1- (A) and T2-weighted (B) images show an ice-cream-cone-shaped mass centered in the left porus acousticus that is isointense to brain parenchyma. Axial (C) and coronal (D) postcontrast fat-suppressed T1-weighted images show avid enhancement of the lesion, without evidence of a dural tail. The findings are characteristic of a vestibular schwannoma (white arrows).
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The imaging appearance was classic for a VS (Fig. 1, A-D).
71-year-old man with post-treatment vestibular schwannoma. Serial followup contrast-enhanced, T1-weighted, fat-suppressed axial MRI sequences obtained after gamma knife radiosurgery. The left-sided vestibular schwannoma (white arrows) shows slight interval enlargement with central nonenhancement of the cisternal component at three months post-treatment (A), consistent with early post-treatment changes expected after stereotactic radiosurgery. Three years after gamma-knife treatment (B), the lesion has not increased in size; the size of the cisternal component is slightly decreased compared to the pretreatment baseline scan (Fig. 1C, above).
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On followup MRI three months after radiotherapy, the lesion appeared slightly larger with new areas of nonenhancement centrally, consistent with necrosis (Fig. 2A). Followup MRI approximately three years after treatment showed slight interval decrease in size of the tumor as compared to the pretreatment baseline MRI (Fig. 2B).