质子磁共振波谱评价颈内和大脑中动脉狭窄与闭塞的脑代谢研究

目的探讨质子磁共振波谱(1H-MRS)在单侧颈内动脉(ICA)和大脑中动脉(MCA)重度狭窄与闭塞中的应用价值。方法32例单侧ICA或MCA重度狭窄或闭塞患者(ICA18例,MCA14例)行1H-MRS检查,测量患侧和对侧大脑半球半卵圆中心N-乙酰天门冬氨酸(NAA)、胆碱(Cho)和肌酸(Cr)的波峰下面积,比较患侧和对侧各代谢物峰下面积比值NAA/Cho、NAA/Cr和Cho/Cr的差异,并观察有无乳酸(Lac)峰出现。结果1H-MRS显示患侧半卵圆中心的NAA/Cho、NAA/Cr低于对侧,差异有显著性意义(P<0.01),Cho/Cr高于对侧,差异有显著性意义(P<0.01),5例患者于患侧检测到Lac峰。结论1H-MRS能够早期发现ICA或MCA重度狭窄或闭塞患者缺血脑组织的代谢异常,从代谢产物角度评价脑缺血程度,对于早期治疗和判断预后具有重要价值。

1H-MR spectroscopy evaluation of cerebral metabolism in ICA and MCA stenosis or occlusion

Objective To explore the value of 1H magnetic resonance imaging(1H-MRS) in patients with unilateral ICA or MCA high-grade stenosis or occlusion.Methods 1H-MRS was performed in 32 patients with ICA(18 patients) or MCA(14 patients) high-grade stenosis or occlusion.Cerebral metabolism was studied by assessing ratios of N-acetyl aspartate(NAA) to choline(Cho) and to creatine(Cr) as well as Cho to Cr in noninfarcted regions of the centrum semiovale in both hemispheres.Results The NAA/Cho and NAA/Cr ratios were significantly decreased in the centrum semiovale on the side of the stenosis or occlusion compared with the control side(P<0.01).In the hemisphere on the side of the stenosis or occlusion,the Cho/Cr ratio was significantly increased compared with control side(P<0.01).Lactate(Lac) was detected in diseased side of 5 patients.Conclusion 1H-MRS could demonstrate the abnormal cerebral metabolic changes and evaluate the cerebral ischemic degree in patients with ICA or MCA high-grade stenosis or occlusion,and play an important role in diagnosis,treatment and prognosis assessment of ICA or MCA stenosis or occlusion.