大脑原始神经外胚层肿瘤的MRI诊断

MRI Diagnosis of Cerebral Primitive Neuroectodermal Tumors

目的:探讨大脑原始神经外胚层肿瘤的MRI表现。材料和方法:回顾性分析5例病理证实的大脑原始神经外胚层肿瘤的MRI表现。病例均行MRI平扫与增强扫描,其中2例加行DWI扫描。结果:肿瘤位于额叶4例和颞叶1例。位于皮层4例,侧脑室旁深部白质1例。肿瘤呈长T1长T2信号3例、长T1稍长T2信号1例、混杂信号1例,DWI呈高信号2例。出现不同程度坏死4例,出血2例。瘤周无明显水肿2例、轻度水肿2例和中度水肿1例。花环状增强3例、团絮状增强1例和斑点状增强1例。脑膜及颅骨受侵2例。结论:大脑原始神经外胚层肿瘤MRI有一定的特点,MRI对其有重要诊断价值。

Purpose： To explore the MRI manifestations of cerebral primitive neuroectodermal tumors（PNETs）.Materials and Methods： The MRI findings of 5 cases cerebral PNETs proved by histology were analysed retrospectively.All cases were scanned with conventional plain and postcontrast MR sequences and 2 cases plus additional DWI.Results： The tumor located in frontal lobe（4 cases） and temporal（1 case）.The tumor mainly involved cortex（4 cases） and deep white matter（1 case）.Tumors showed long T1,long or slight long T2 signal intensity in 4 cases and mixed signal intensity in 1 case.DWI showed high signal intensity in the two cases.Four lesions accompanied with cystic change and 2 lesions with bleeding.All the tumors had some extent perifocal edema from obvious（3 cases）,medium（1 case） to slight（2 cases）,and had chaplet like（3 cases）,floccular（1 case） or punctuate（1 case） contrast enhanced.The adjacent bone and meninges were eroded in 2 cases.Conclusion： Cerebral PNETs have some features on MRI,which may help the diagnosis.