MRI在慢性期脑梗死Wallerian变性中的诊断价值

MRI diagnostic value on cerebral infarction Wallerian degeneration in pyramidal tract

目的：探讨慢性期脑梗死锥体束华勒氏变性（ WD）的磁共振诊断价值。方法搜集单侧大脑半球病变的继发WD患者20例，均行常规MRI（T1WI、T2WI、FLAIR）及DWI功能成像。结果 WD表现为单侧大脑半球陈旧性脑梗死，并出现不同程度的继发性表现，沿锥体束走行并与原发病灶相连或不相连的斑片状等T1、长T2异常信号，FLAIR中央低信号，边缘高信号（20例）；另7例合并患侧大脑脚、桥脑萎缩。结论 MRI能准确反映中枢神经WD系由神经元近端损伤累及远段轴突和髓鞘的顺行性变性的原发和继发性变性病变的特征性改变，从而提高对该变性的认识，提高诊断准确性。

Objective To analyze the MR findings of Wallerian degeneration in pyramidal tract,so as to improve the diagnosis accuracy. Methods Twenty cases of Wallerian degeneration in pyramidal tract were analyzed by MR,with T1WI,T2WI,FLAIR and DWI. Results A total of 20 cases of Wrallerian degeneration in pyramidal tract showed unilateral pulmonary cerebral infarction cerebral hemisphere,and with secondary findings,including cerebral peduncle and pons atrophy（7 cases）,or the long T1/T2 signal and high signal in FLAIR along the pyramidal tract. Conclusions MRI can show the morphological changes from neurons to axons and myelin sheath in Wallerian degeneration correctly,and it is valuable in the diagnosis of Wallerian degeneration in pyramidal tract.