丘脑Ⅱ级星形细胞瘤的MRI表现

MRI features of thalamic WHO grade Ⅱ astrocytoma

目的:探讨丘脑Ⅱ级星形细胞瘤的MRI表现,以提高对该病的诊断准确率。方法:回顾性搜集16例经病理证实为丘脑Ⅱ级星形细胞瘤患者的临床和MRI资料。结果:16例丘脑Ⅱ级星形细胞瘤中,13例病灶位于单侧丘脑,3例病灶位于双侧丘脑。病灶的形态分两类:形态规则、边界清楚(7/16)和弥漫性生长、边界模糊(9/16)。常规MRI信号分两种:信号均匀的实性肿块(12/16)和信号混杂的囊实性肿块(4/16),瘤周水肿均不明显。肿瘤实质的DWI信号包括3种:稍高信号(5/12)、等信号(5/12)和低信号(2/12)。增强扫描强化方式有3种:不强化(7/13)、斑点及斑片状强化(2/13)和不规则环形强化(4/13)。磁共振波谱(MRS)表现为两种形态:Cho峰高于Cr峰(3/7)和Cr峰高于/等于Cho峰(4/7)。结论:丘脑Ⅱ级星形细胞瘤的MRI表现具有一定的特征性,结合其病灶形态、MRI信号特征、强化方式及MRS波形,有助于提高对该病的诊断率。

Objective:To investigate the MRI features of thalamic WHO gradeⅡastrocytoma,and to improve the accuracy rate of diagnosis.Methods:The clinical and MRI materials of 16 patients with thalamic WHO gradeⅡastrocytoma confirmed by pathology were retrospectively collected.Results:Of the 16 thalamic WHO gradeⅡastrocytomas,13 cases located in unilateral thalamus,and 3 cases occurred in bilateral thalamus.In our study,the morphology of lesions showed 2 types:regular and well-circumscribed growth(7/16),diffuse growth and indistinct border(9/16).MRI signals included 2 kinds:solid mass with homogenous signal(12/16),inhomogenous solid-cystic mass(4/16).DWI signal showed 3 kinds:slightly hyperintense(5/12),isointense(5/12)and hypointense(2/12).The enhancement feature of solid component in tumors showed 3 types:non-enhancement(7/13),stippled and patchy enhancement(2/13),irregular circular enhancement(4/13).MRS pattern showed 2 kinds:cho peak was significant higher than Cr peak in 3 cases(3/7),Cr peak increased in 4 cases(4/7).Conclusion:MRI appearance of thalamic WHO gradeⅡastrocytoma have certain characteristics.Diagnosis can be made confidently when the morphology,MRI signal,enhancement features and MRS patterns are all considered.