原发性颞叶内侧癫痫伽玛刀治疗后放射性坏死的MRI诊断

目的：探讨原发性颞叶内侧癫痫伽玛刀治疗后出现放射性坏死的磁共振表现。方法：搜集2002年～2009年经伽玛刀治疗原发性颞叶内侧癫痫后MRI复查出现放射性坏死患者共13例,评价其磁共振表现。结果：放射性坏死出现时间9～67个月,平均时间为26.2个月。放射性坏死的MRI表现：照射侧颞叶内部大片状长T1长T2信号,静脉注射Gd-DTPA病灶中心不规则花环状强化,周围大片水肿,占位效应明显,强化灶大于照射野,治疗后病灶可缩小。结论：原发性颞叶内侧癫痫伽玛刀治疗后放射性坏死的出现时间及其磁共振表现具有特征性,磁共振检查有助于放射性坏死的早期诊断并指导临床治疗。

MRI diagnosis of radiation-induced necrosis after gamma knife radiosurgery for primary mesial temporal lobe epilepsy

Objective：To evaluate the MRI features of radiation-induced necrosis after gamma knife radiosurgery for primary mesial temporal lobe epilepsy. Methods：Thirteen consecutive patients with gamma knife radiosurgery for primary mesial temporal lobe epilepsy from 2002 to 2009 were enrolled in this study. They were all diagnosed as radiation-induced necrosis by repeated MRI. The MR images were retrospectively analyzed. Results：The duration from gamma knife radiotherapy to occurrence of necrosis was 9～67 months,the mean interval was 26.2 months. MRI appearance of radiation-induced necrosis included large patchy long T1 and long T2 signal intensity in the radiated mesial temporal lobe with central irregular ring-like enhancement after Gd-DTPA administration. Surrounding edema and mass effect were conspicuous. The enhanced part was larger than the radiation target,and its volume can be decreased after medication. Conclusion：The occurrence interval and MRI manifestation of radiation-induced necrosis after gamma knife radiosurgery for primary mesial temporal lobe epilepsy are characteristic,MRI is valuable for early diagnosing of radiation-induced necrosis and guiding clinical medication.