少突-星形细胞肿瘤的CT和MRI表现

CT and MRI manifestations of oligoastrocytic tumors

目的探讨少突-星形细胞肿瘤的CT和MRI特征性表现。方法回顾性分析经手术病理证实的20例少突-星形细胞肿瘤的CT和MRI表现。结果 20例中,少突-星形细胞瘤18例,间变性少突-星形细胞瘤2例,均发生于大脑半球,以额叶较常见,可跨脑叶生长,部分发生于胼胝体。10例肿瘤出现囊变,5例肿瘤见钙化。CT见病灶多呈混杂密度,增强后无强化或不均匀性强化。MRI示肿瘤多以长或稍长T1长T2信号为主;DWI 5例肿瘤实质部分呈稍高信号,ADC值约(1.40±0.25)×10-3mm2/s;增强后肿瘤呈环状、花环状或不均匀性强化。肿瘤周围多可见轻度水肿。结论少突-星形细胞肿瘤多位于大脑半球,以实性病灶为主,CT和MRI表现具有一定特征性。

Objective To investigate the characteristic CT and MRI findings of oligoastrocytic tumors.Methods CT and MRI findings in 20 patients of oligoastrocytic tumors proved with operation and pathology were analyzed retrospectively.Results Among 20 patients,there were 18 oligoastrocytomas and 2 anaplastic oligoastrocytomas.Cerebral hemisphere was the predilection site of oligoastrocytic tumors,which mostly located in the frontal lobe.Some tumors extended to other lobes,some located in the corpus callosum.Cystic degeneration was found in 10 and calcification in 5 patients.On CT images,tumors tended to appear as mixed density,no enhancement or heterogeneous enhancement was found.Most tumors appeared as low or slight low signal intensity on T1WI and high signal intensity on T2WI.Five oligoastrocytomas showed slightly high signal intensity on DWI,and the mean of ADC values was（1.40±0.25）×10-3 mm2/s.Rim,wreath enhancement or heterogeneous enhancement were observed.Slight peripheral edema of focus was observed in most of the tumors.Conclusion Most oligoastrocytic tumors locate in cerebral as substantial neoplasm.Oligoastrocytic tumor has characteristic imaging appearances on CT and MRI.