말초성 신경초종의 자기공명영상;병리학적 소견과의 비교

Abstract

Purpose : To characterize the MRI appearance of the peripherally located schwannoma as compared withpathologic findings. Materials and Methods : 11 cases of 13 lesions of the schwannoma confirmed by pathology wereanalyzed, retrospectively. T1,T2 and Gadolinium-enhanced T1 weighted sagittal and axial images were obtained. Thesignal intensity, contour of lesion, and relationship with surrounding tissue were analyzed. All cases werecorrelated with MRI and pathologic findings. Results : In 9 Out of the 11 cases schwannoma were connected to themain nerve trunk course. Among them, tumors were located centrally in 6 cases and eccentrically in 3 cases. MRfindings of schwannoma were iso signal intensity on T1WI(8 cases) with muscle intensity, high signal intensity onT2WI(all cases), strong heterogenous enhancement in all cases. 8 cases showing heterogenous appearance on T2WI,showed mixture of Antoni-A and B area and multifocal hemorrhage. Central low and peripheral high signal intensityon T2WI(Target sign) was mainly high cellular component in the central portion and diffuse myxoid degeneration atthe periphery, pathologically. Reversed target appearance(central high, peripheral low on T2WI) revealed centralcystic degeneration with low cellular component and hemorrhage in the central portion, and high cellular componentat the periphery. Linear band-like low signal intensity on T2WI, suggesting capsule of the schwannoma, was not thetrue capsule proven by pathology. Thin true capsule was not visualized on T2WI. Conclusion : MR appearance ofschwannoma was non-specific. The signal intensity on T2 weighted MR imaging was determined by the presence ofmultifocal hemorrhage, focal cystic and myxoid degeneration, admixture of Antini-A and B area.