Cystic acoustic schwannomas: MR characteristics.

摘要: PURPOSE To evaluate the spectrum of MR characteristics cystic acoustic schwannoma and to investigate its incidence. METHODS We retrospectively reviewed findings clinical records 16 patients with schwannomas. In addition, examinations 411 consecutive referred for suspicion schwannomas were assess incidence lesions arising from internal auditory canal. RESULTS Of evidence intramural cysts, 11 tumors had single small five multiple cysts variable size. Intramural in exhibited higher signal intensity than that cerebrospinal fluid; remainder isointense fluid on both T1- T2-weighted images. All showed circumferential enhancement after contrast administration. Nine also extramural/arachnoid cysts. Six epicenters away dural interface, other three broadly based against dura. The was 11.3% association 7.5%. CONCLUSION Our series suggests changes are not as rare previously reported by diagnostic methods. high is probably related necrotic material, blood, or colloid-rich fluid. difference associated those typical arachnoid neoplasia may be protein and/or colloid contents secreted tumor. Most between tumor brain, suggesting most likely mechanism formation peritumoral adhesions. It creates a pseudo-duplication caused trapping leptomeninges mass, resulting an acquired type cyst.