胶质母细胞瘤的常规MRI诊断

The conventional MRI diagnosis of glioblastomas

目的:通过分析胶质母细胞瘤的MR表现,探讨其影像学特征。方法:回顾性分析21例经手术病理证实的胶质母细胞瘤的临床资料及MRI特征,对肿瘤的发病部位、形态、信号、瘤周水肿、占位效应以及强化特征进行分析。结果:20例病灶位于大脑半球,1例位于小脑半球,其中4例跨中线生长。MR表现为长T1、长T2为主的混杂信号团块20例,结节状1例,21例中16例有"流空效应",阳性率为76.2%;增强扫描呈厚薄不一的不规则花环状、花瓣状强化18例,整个病灶或环壁呈"栅栏"状,19例增强病例中18例可见假"栅栏"征,阳性率达94.7%,1例呈结节状轻度强化。20例病灶有明显瘤周水肿和占位效应,仅1例不明显。结论:胶质母细胞瘤具有一定特征性MR表现,肿瘤体积较大,累及多个脑叶,形态不规则,信号不均匀,囊变坏死多见,瘤内可见出血,可跨中线生长,水肿和占位征象明显。尤其是假"栅栏"征及"流空效应"对诊断胶质母细胞瘤更具特征性。

Objective：To analyze the magnetic resinance（MR） imaging manifestations of glioblastomas and discuss its MR imaging characteristics.Methods： To retrospectively analyze the clinical data and MRI characteristics in 21 cases with glioblastoma proven by surgery and pathology,as well as analyze the tumor location,form,signal,peri-tumoral edema,mass effect and its strengthening features.Results： there were 20 cases where the tumors were located in the cerebral hemisphere,one case where the tumor was located in cerebellar hemisphere,four cases where the tumors across the central line growth.Masses with long T1 and long T2 or mixed signal intensities were showed in 20 cases in MRI,nodular in one case,＂flow void＂ in 16 cases of the 21 cases with a positive rate of 76.2 %.After contrast administration,the lesions showed irregular ring-like or petal-like enhancement with varied thickness,and the whole lesions or ring wall was the ＂pseudopalisade＂ shape.There were 18 of 19 enhanced cases,which had the ＂pseudopalisade＂ sign,94.7 % for the positive rate,and nodules mild strengthening in one case.Significantly,Peri-tumoral edema and local mass effect was shown in 20 cases,and one case was not obvious.Conclusion： The MR imaging findings of glioblastomas have some speciality in the diagnosis The tumor shows larger size,invading adjacent lobes of the brain,irregular tumors form,heterogeneous signal intensity,cystic degeneration,necrosis,and hemorrhage within the tumor across the central line growth,Marked peri-tumoral edema and mass effect.and especially the ＂pseudopalisade＂ sign and ＂flow void＂ are more characteristic to the diagnosis of glioblastomas.