用MR扩散加权成像评价新生儿缺氧缺血性脑病的初步研究

Preliminary study on hypoxic-ischemic encephalopathy in neonates with diffusion-weighted MR imaging

目的 应用扩散加权成像 (DWI)方法评价新生儿缺氧缺血性脑病 (HIE) ,并同常规MRI对照 ,以了解扩散成像的价值及限度。方法 对临床确诊的 36例缺氧缺血性脑病的新生儿 (年龄 3h至 2 2d ,平均 8 4 4d) ,进行常规MRT1WI和DWI检查 (b =70 0s/mm2 )。观察皮层及皮层下白质、深部白质、基底节及丘脑、脑室及脑外间隙等部位。结果 缺血缺氧所致脑损害在DWI表现为弥漫性损害 :区域性皮层、皮层下及深部白质较广泛的高信号 19 4 % (7/ 36 ) ;局灶性损害 :沿侧脑室壁和三角部白质的高信号 2 7 8% (10 / 36 ) ,额叶深部白质点状高信号 5 6 % (2 / 36 )。相应部位的T1WI分别为16 7% (6 / 36 ) ,36 1% (13/ 36 ) ,30 6 % (11/ 36 )。出血性病变 ,在T1WI上为高信号 ,而在DWI上表现为无信号。结论 MRDWI适于早期检查HIE ,T1WI适于亚急性期和慢性期。

Objective To evaluate hypoxic-ischemic encephalopathy (HIE) in neonates with diffusion-weighted MR imaging, and to explore the value and limitation of diffusion-weighted imaging (DWI) compared with conventional magnetic resonance imaging.Methods Conventional magnetic resonance T 1-weighted imaging (T 1WI) and DWI (b=700 s/mm2) were performed in 36 neonates with HIE ( average age, 8.44 days; range, 3 hours to 22 days ), and the cortex and subcortical white matter, deep white matter, basal ganglia and thalamus, cerebral ventricle, and extra-cerebral interspace etc were observed.Results Signal abnormalities were shown on DWI with hypoxic-ischemic insults, which included diffuse brain damage (19.4%, 7/36): extensive high signals in the regional cortex, subcortical and deep white matter; localized brain damage: high signals along lateral ventricular wall and triangular part (27.8%, 10/36 ), and punctate high signals in the frontal deep white matter (5.6%, 2/36).On T 1WI, the incidence of the corresponding changes were 16.7% (6/36), 36.1% (13/36), and 30.6%(11/36), respectively.Hemorrhagic lesions demonstrated high signals on T 1WI and no signals on DWI.Conclusion DWI was applicable for acute HIE, and T 1WI was suitable for subacute and chronic HIE.