MR动脉血质子自旋标记与波谱成像在颈内动脉系统狭窄或闭塞的应用研究

目的 探讨MR动脉血质子自旋标记(ASL)与氢质子磁共振波谱成像(1H-MRS)在颈动脉系统狭窄或闭塞的应用价值. 资料与方法 28例单侧颈内动脉(ICA)/大脑中动脉(MCA)重度狭窄或闭塞患者行ASL 和1H-MRS检查.对ASL后处理的相对脑血流量(CBF) 图进行定性和定量分析;对1H-MRS测量病变侧和对侧脑组织的氮-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)的波峰下面积,比较两侧各代谢物峰下面积比值(NAA/Cho、NAA/Cr、Cho/Cr)的差异,并观察是否出现乳酸(Lac)峰. 结果 28例CBF图显示18例病变侧灌注较对侧降低,10例未见明显异常;1H-MRS显示病变侧的NAA/Cho、NAA/Cr低于对侧,差异有统计学意义(P<0.01),Cho/Cr高于对侧,差异有统计学意义(P<0.01),3例于病变侧检测到Lac峰. 结论 ASL 能够早期发现颈动脉系统狭窄或闭塞患者的CBF改变,1H-MRS能够显示缺血脑组织的代谢异常.

The Application of MR Arterial Spin Labeling and Spectroscopy in Carotid System Stenosis or Occlusion

Objective To explore the value of magnetic resonance imaging arterial spin labeling(ASL)and 1H spectroscopy (1H-MRS) in patients with unilateral ICA/ MCA high grade stenosis or occlusion. Materials and Methods ASL and 1H-MRS were performed in 28 patients with ICA (14) / MCA (14) high grade stenosis or occlusion. The cerebral blood flow (CBF) map was calculated, and the qualitative and quantitative analysis was carried out on the occluded side and contralateral side. 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 from noninfarcted regions in the centrum semiovale in both hemispheres. Results The CBF decreased were depicted in 18 patients with ICA/MCA high grade stenosis or occlusion. The signal intensity values of CBF had statistically significant difference between the side of the stenosis or occlusion and contralateral side(P<0.01).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 contralateral side(P<0.01). However, the Cho/Cr ratio was significantly increased compared with contralateral side(P<0.01). Lactate (Lac) was observed in 3 patients. Conclusion ASL and 1H-MRS could demonstrate the abnormal cerebral perfusion and metabolic changes in patients with ICA/ MCA high grade stenosis or occlusion.