磁共振灌注成像定量评估儿童烟雾病血管重建术后血流动力学变化

Quantitative evaluation of hemodynamics changes in childhood moyamoya disease after revascularization surgery using perfusion-weighted MR imaging

目的利用磁共振灌注成像（perfusion-weighted imaging,PWI）定量分析儿童烟雾病患者血流动力学状态与传统脑血管造影之间的关系,评估首次血管重建术后血流动力学变化情况及其与临床预后的关系。材料与方法回顾性分析16例儿童烟雾病患者（5~15岁,平均9.88岁）血管重建术前及首次术后（平均间隔4.08个月）MR-PWI参数,包括局部达峰时间（regional time to peak,r TTP）、局部脑血容量（regional cerebral blood volume,r CBV）、局部脑血流量（regional cerebral blood fl ow,r CBF）、局部平均血流通过时间（regional mean transit time,r MTT）及每侧大脑半球（共32侧）的铃木分期（Suzuki Stages）情况,并与临床预后进行比较。采用配对t检验比较手术前后MR-PWI参数变化情况,采用独立样本t检验观察PWI参数变化情况与临床预后的关系,MR-PWI参数与铃木分期关系采用Spearman秩相关分析;检验水准：P〈0.05。结果儿童烟雾病患者早期血流灌注变化与铃木分期相关,当疾病进展至Ⅱ期以上时,灌注参数变化与铃木分期不相匹配;血管重建术后,r TTP较术前显著缩短,而r CBV、r CBF、r MTT变化无统计学差异;r TTP的变化情况与不同的临床效果相关。结论利用磁共振灌注扫描可以定量评估儿童烟雾病患者血流动力学状态及血管重建术后血流动力学改善情况,且由于其无辐射与简便易行的特点,值得在临床推广。

Objective： To evaluate whether Perfusion-Weighted Imaging（PWI） can depict hemodynamic status and its relationship with Digital Subtraction Angiography（DSA） and whether changes in PWI imaging after revascularization surgery are correlated with clinical outcomes in childhood moyamoya disease. Materials and Methods： Pre- and postoperative PWI imaging data in 16 children with moyamoya disease（mean age, 9.88 years; range, 5-15 years） were included, which involved regional Time To Peak（r TTP）, regional Cerebral Blood Volume（r CBV）, regional Cerebral Blood Flow（r CBF） and regional Mean Transit Time（r MTT）. Suzuki stages on each side of the brain hemisphere were evaluated by the DSA results. Pre- and postoperative PWI parameters were compared by using a paired t test; relationships between PWI parameters and clinical outcomes were investigated byusing independent-samples t test; relationships between PWI parameters and Sukuzi Stages were investigated by using Spearman correlation analysis, with a significance level of 0.05. Results： At early stage of MMD, Suzuki stages were correlated with blood perfusion change. However, no correlation was demonstrated when suzuki stages〉 II. r TTP decreased signifi cantly after revascularization surgery. Change in r TTP was signifi cantly different in the clinical outcome groups. Conclusion： MR-PWI can quantitatively depict hemodynamic status and evaluate hemodynamic changes after revascularization surgery in moyamoya disease.