三维动脉自旋标记在超急性期脑梗死中的初步应用

目的 初步探讨三维伪连续动脉自旋标记(3D-pcASL)灌注成像在超急性期脑梗死诊断及溶栓治疗中的应用价值。 方法 回顾性分析2014年9月-2016年4月扬州大学附属医院7例超急性期脑梗死患者的临床资料。溶栓前后均行磁共振血管成像(MRA)、扩散加权成像(DWI)及3D-pcASL灌注成像,观察溶栓前病变大小及信号特征、动脉闭塞及血流灌注情况;评价血流灌注与责任动脉是否一致;比较3D-pcASL与DWI上病变的范围,确定两者匹配情况,是否存在缺血半暗带。观察溶栓后闭塞动脉是否再通、病变大小及血流灌注的变化、是否存在低灌注和(或)高灌注;评价血流灌注与病变大小、动脉再通程度的相关性。 结果 溶栓前7例MRA显示一侧大脑中动脉M₁段闭塞,其中1例合并同侧颈内动脉闭塞;DWI显示同侧大脑半球多发、散在点片状高信号区;3D-pcASL显示大面积低灌注区,3D-pcASL上低灌注区与动脉闭塞一致,且低灌注区范围均明显较DWI上高信号区大,存在缺血半暗带。溶栓后5例MRA显示大脑中动脉M₁段再通,远端分支显示,1例大脑中动脉主干再通,部分远端分支未显示,1例大脑中动脉M₁段和同侧颈内动脉再通,大脑中动脉部分远端分支未显示;7例DWI显示高信号区缩小;3例3D-pcASL显示大面积高灌注区,低灌注区消失,4例低灌注区缩小,其中1例出现条片状高灌注区;3D-pcASL上出现高灌注区或低灌注区缩小与DWI上高信号区缩小一致,且与动脉再通程度一致。 结论 3D-pcASL能较可靠地反映超急性期脑梗死的血流低灌注,并能评价缺血再灌注以及溶栓治疗的效果,是一种完全无创的磁共振灌注成像方法。 

Preliminary application of three-dimensional arterial spin labeling MRI in diagnosis and treatment of hyperacute cerebral infarction

Objective To investigate the application of 3D pseudo-continuous arterial spin labeling (3D-pcASL) perfusion MRI in the diagnosis and thrombolytic therapy of hyperacute cerebral infarction. Methods The clinical data of 7 cases of hyperacute cerebral infarction in our hospital between September, 2014 and April, 2016 were analyzed retrospectively. The magnetic resonance angiography (MRA), diffusion weighted imaging (DWI) and 3D-pcASL perfusion imaging were performed before and after thrombolysis in all cases. Before thrombolysis, the size of lesions and signal characteristics, artery occlusion and blood perfusion was observed; the relationship between blood perfusion and offending artery was evaluated; the scope of lesions on 3D-pcASL and DWI was compared to identify their matching conditions and ischemic penumbra. After thrombolysis, the occluded artery recanalization, size of lesions and blood perfusion change, low or high perfusion was observed. The correlation between blood perfusion, size of lesions and degree of artery recanalization was evaluated. Results Before thrombolysis, MRA displayed middle cerebral artery M₁ segment occlusion in 7 cases, ipsilateral internal carotid artery occlusion in 1 case. DWI showed ipsilateral massive hemispheric high signal area in 7 cases. 3D-pcASL showed large low perfusion area in 7 cases, low perfusion area and artery occlusion was consistent, but it was larger than high signal area on DWI, ischemic penumbra existed. After thrombolysis, MRA displayed middle cerebral artery M₁ segment and its branches recanalization in 5 cases, middle cerebral artery recanalization and distal branches undeveloped in 1 case, middle cerebral artery M₁ segment and ipsilateral internal carotid artery recanalization, middle cerebral artery distal branches undeveloped in 1 case. High signal area reduced on DWI in 7 cases. 3D-pcASL displayed massive hemispheric high perfusion area in 3 cases, low perfusion area reduced in 4 cases, including patchy high perfusion area in 1 case. High or low perfusion area narrowing, high signal area narrowing and degree of artery recanalization was consistent. Conclusion 3D-pcASL can reliably reflect the low blood perfusion of hyperacute cerebral infarction, evaluate ischemia reperfusion and effect of thrombolytic therapy. It is a completely non-invasive magnetic resonance perfusion imaging method.