磁共振弥散张量成像在急性缺血性脑卒中评估中的应用

To Investigate the Application of Magnetic Resonance Diffusion Tensor Imaging in the Assessment of Acute Ischemic Stroke

目的采用磁共振弥散张量成像(DTI)评价急性缺血性脑卒中所致皮质脊髓束(CST)损伤程度与预后的关系.方法选取我院2019年6月—2021年2月收治的急性缺血性脑卒中患者50例为研究对象,于发病后72 h内、发病3周后及发病3个月后分别进行磁共振成像(MRI)及DTI检查,获取影像数据后分别测量梗死灶、健侧相应区域及双侧大脑脚外侧部部分各向异性(FA)值,对患者CST进行分级,并对其康复治疗前后的肌力水平进行评价,研究FA值与患者CST损伤及肌力恢复的关系.结果在首次检查中,患者梗死灶内FA值明显低于健侧正常脑组织FA,差异有统计学意义(P<0.05);患侧、健侧大脑脚FA值比较,差异无统计学意义(P>0.05).发病3周后复查结果显示,患者梗死灶内FA值低于首次检查时,患侧大脑脚FA值明显低于首次检查时,差异均有统计学意义(P<0.05).根据首次MRI检查结果进行CST等级评价,并结合患者康复治疗3个月后的肌力恢复水平进行Sperman等级相关性分析,结果显示患侧CST等级与肌力恢复水平呈负相关关系(r=-0.667,P<0.05).恢复良好患者大脑脚相对FA(rFA)值明显高于部分恢复、无恢复患者,且部分恢复患者大脑脚rFA值明显高于无恢复患者,差异均有统计学意义(P<0.05).结论通过DTI技术测量急性缺血性脑卒中患者的FA值,可评价其CST等级,CST等级与患者肌力恢复密切相关,因此,大脑脚rFA值可为患者CST损伤及预后判定提供量化指标.

Objective To evaluate the relationship between the degree of corticospinal tract(CST)injury and prognosis in acute ischemic stroke by magnetic resonance diffusion tensor imaging(DTI).Methods 50 patients with acute ischemic stroke admitted to our hospital from June 2019 to February 2021 were selected as the study subjects.Magnetic resonance imaging(MRI)and DTI were performed within 72 h after onset,3 weeks after onset and 3 months after onset,respectively.After obtaining the image data,the fraction anisotropy(FA)values of the infarct focus,the corresponding area of the healthy side and the lateral part of the bilateral cranium and foot were measured respectively,the CST of the patients were graded,the muscle strength level before and after rehabilitation was evaluated,and the relationship between FA value and CST injury and muscle strength recovery of the patients was studied.Results In the first examination,the value of FA in the infarction was significantly lower than that in the normal brain tissue on the healthy side,and the difference was statistically significant(P<0.05);while there was no significant difference in FA values between the affected side and the healthy side(P>0.05).Reexamination results 3 weeks after the onset showed that FA value in the infarct was lower than that in the first examination,and FA values in the brain and foot of the affected side were significantly lower than that in the first examination,the differences were statistically significant(P<0.05).The CST grade was evaluated according to the results of the first MRI examination,and the Sperman grade correlation analysis was performed in combination with the muscle strength recovery level of the patients 3 months after rehabilitation treatment.The results showed that the CST grade of the affected side was negatively correlated with the muscle strength recovery level(r=-0.667,P<0.05).The relative FA(rFA)values of cerebrum and foot in patients with good recovery was significantly higher than that in patients with partial recovery and no recovery,and the rFA values of cerebrum and foot in patients with partial recovery was significantly higher than that in patients with no recovery,the differences were statistically significant(P<0.05).Conclusion THE CST grade can be evaluated by measuring FA value of patients with acute ischemic stroke by DTI technique.CST grade is closely related to patients'muscle strength recovery.Therefore,rFA value of cerebrum and foot can provide quantitative indicators for CST injury and prognosis of patients.