少突胶质细胞肿瘤的MRI表现与病理分级分析

MRI Features and Pathologic Grading of Oligodendroglia Tumors

目的探讨少突胶质细胞肿瘤的MRI表现及其病理分级。方法回顾性分析29例少突胶质细胞肿瘤的MRI表现,并结合病理对照分析。结果均为单发病灶,其中Ⅱ级20例,Ⅲ级9例。肿瘤好发于大脑半球皮层下白质,以额叶最常见,可向皮层延伸而伴皮质增厚,可呈不规则斑片状或类圆形,多呈稍长T1、T2信号,多伴囊变坏死,部分可呈囊实性或囊性病灶,且囊实性病灶的壁结节常位于皮层侧或囊性病灶常伴皮层侧囊壁增厚,可伴钙化、出血信号;瘤周多伴轻度水肿或无水肿,增强后多呈不均匀轻度强化或明显强化。Ⅲ级肿瘤在形态上(呈类圆形)、囊变坏死、占位效应、明显强化的比例上均较Ⅱ级偏高,但差异均无统计学意义。结论少突胶质细胞肿瘤的MRI表现具有一定特征性,依据其不同影像学特征,可提高定性诊断及分级的准确性,为临床治疗提供帮助。

Objective To investigate MRI features and athological grading of oligodendroglia tumors, and to discuss the correlation between MRI features and the pathological characteristics. Methods MRI features of 29 patients with oligodendroglia tumor were retrospectively analyzed, The findings were compared with pathological results. Results The lesion was solitary in all patients. Grade H lesion was seen in 20 cases, and Grade m lesion was seen in 9 cases. The tumor preferred to develop at cerebral subcortical white matter, mainly in the frontal lobe. The lesions might extended from the subcortical white matter to cortical layer with thickened adjacent cortical layer, which was characterized by irregular patchy or quasi-circular shape as well as long T1 and long T2 signals. Cystic necrosis often happened in oligodendroglia tumor, which led to cystic or solid-cystic degeneration, and the wall nodule of cystic-solid lesions usually located in cortical side, as cystic lesions usually accompanied by thickened capsule wall in cortical side. Bleeding or calcification signal in tumor might be detected. Most adjacent area of the tumor had mild edema or had no edema. And the tumor usually showed slightly or sig- nificantly enhancement on enhanced scanning. Compared with Grade Ⅱ lesions, the cystic degeneration, the space-occupying effect and the degree of enhancement of Grade Ⅲ lesions were more common, although the differences between grade Ⅱand grade Ⅲ were not statistically significant. Conclusion Oligodendroglia tumors have certain MRI characteristics, which are very helpful in making diagnosis and classification as well as in guiding the clinical treatment.