锥体束Wallerian变性的MRI诊断

目的探讨MRI在诊断脑损害后锥体束Wallerian变性中的应用。方法对22例脑损害后锥体束Walle-rian变性患者均行MRI检查。常规行快自旋回波序列(FSE)横断位T1WI(TR 2 286ms,TE 19.6ms)、T2WI(TR4 300ms,TE 113ms)和T2Flair序列(TR 8 502ms,TE 133ms)。视野(FOV)24cm,矩阵320×256,激发次数(NEX)1～2,层厚6mm,层间距1mm,层数21层。22例患者均加扫横轴位DWI(b值为1 000s.mm-2),其中10例另加扫3D-TOF-MRA(TR 26ms,TE 6.8ms)检查。结果 22例患者中,12例患者在脑损害≥4周～≤12个月后行常规MRI检查,主要表现为病变同侧的锥体束呈长T1、长T2信号并同侧大脑脚及桥脑体积稍萎缩;2例患者在脑损害<4周行常规MRI检查,主要表现为病变侧锥体束稍长T1、长T2信号;8例患者在脑损害>1年行常规MRI检查,主要表现为原发病灶、大脑脚及桥脑萎缩并T2Flair像呈现散在斑片稍高信号影。结论 MRI可明确显示脑损害后锥体束Wallerian变性,有助于临床医师对患者运动功能康复的治疗。

MRI Diagnosis of Wallerian Degeneration of Pyramidal Tract

Objective To explore the application of MRI diagnosis of Wallerian degeneration of pyramidal tract after brain injury.Methods Twenty-two patients with Wallerian degeneration of pyramidal tract after brain injury underwent MRI examination（FSE T1WI TR/TE 2 286/19.6 ms;T2WI TR/TE 4 300/113 ms;T2 Flair sequence TR/TE 8 502/133 ms;FOV 24 cm;Matrix 320×256;NEX 1-2;slice thickness：6 mm;interlayer spacing 1 mm;layers 21）.An axial DWI scan（b value 1 000 s·mm-2） was performed in all patients.Among them,3D-TOF-MRA examination（TR/TE 26/6.8 ms） was additionally carried out in 10 patients.Results Among the 22 patients,12 underwent MRI examination at ≥4 weeks-≤12 months after brain injury and showed elongated T1 and T2 signals in pyramidal tract ipsilateral to the lesion and slight atrophy of ipsilateral cerebral peduncle and pons.Two patients underwent MRI examination at 4 weeks after brain injury and showed longer T1 and long T2 signals.Eight patients underwent MRI examination at 1 year and showed primary lesion,cerebral peduncle and pons atrophy,and increased T2 Flair signal as scattered patches.Conclusion MRI may clearly show Wallerian degeneration of pyramidal tract after brain injury and can help clinicians treat impaired motor function.