连续动脉自旋标记磁共振灌注成像对足月缺氧缺血性脑病患儿的初步研究

Continuous arterial spin labeling MR perfusion imaging in diagnosis of hypoxic ischemic encephalopathy in full-term neonates:Preliminary study

目的应用连续动脉自旋标记(continuous arterial spin labeling,CASL)磁共振灌注的方法对足月缺氧缺血性脑病(hypoxic ischemic encephalopathy,HIE)患儿脑血流量(cerebral blood flow,CBF)进行定量测量,旨在研究新生儿HIE早期血流动力学改变。方法对足月缺氧缺血性脑病新生患儿12例及足月正常对照组新生儿各12例在产后8～24h、48h、7～12d分别进行常规T1WI、T2WI、DWI以及CASL磁共振灌注检查。采用FunctoolⅡ软件包重建每个研究对象的CBF图,测得双侧顶叶皮层、放射冠白质、基底节区的脑血流量(CBF)。结果在正常对照组,足月儿顶叶皮层的CBF比基底节区的低,具有显著的统计学差异(P<0.01),白质CBF相对灰质为低,具有显著统计学差异(P<0.01)。实验组各感兴趣区8～24hCBF值与对照组水平相比明显减低,具有显著统计学差异(P<0.05)。在缺氧缺血后48h,实验组白质CBF值与对照组无明显差异,基底节区和顶叶皮层的CBF显著高于对照组(P<0.05)。7～12d实验组与对照组各感兴趣区CBF无明显差异。在生后48h,实验组顶叶皮层和基底节区(P<0.05)出现充血现象。结论 CASL磁共振灌注成像技术对于新生儿HIE早期诊断具有重要价值。

Objective： To investigate continuous arterial spin labeling （CASL） MR perfusion imaging in the quantitatively evaluation of early hemodynamic change in patients suffered from hypoxic ischemic encephalopathy （HIE）. Materials and Methods： Twelve cases of full-term neonates suffered from HIE and 12 normal controls in 8-24 hours, 48 hours, and 7-12 days were recruited for MR T1 weighted, T2 weighted, diffusion weighted imaging, and CASL examination. Cerebral blood flow （CBF） colour maps were obtained using Functool II package, and CBF values of bilateral patietal cortex, corona radiata, and basal ganglia were calculated. Results： CBF of parietal cortex was lower than that of basal ganglia （P〈0.01）, and CBF of white matter was lower than that of cortex （P〈0.01） in normal full-term neonates. CBF values in patients were significant decreased in each region of interest at 8-24 hours postnatal timepoint when compared with normal controls （P〈0.05）; However, no significant difference of CBF values in white matter, and significant difference of CBF values in both cortex and basal ganglia （P〈0.05） were present 48 hours after hypoxic insult. There was no significant difference of CBF values in each region of interest 7-12 days after hypoxic insult when patients and normal controls were compared. Forty-eight hours after birth, the experimental group parietal cortex and basal ganglia （P〈0.05） appeared congestive phenomena. Conclusion： CASL MR perfusion imaging plays an important role in the early diagnosis of HIE.