扩散加权成像在早期诊断早产儿局灶性脑白质损伤及其预后的价值

Early Diagnostic and Prognostic Value of Diffusion Weighted Imaging In Premature Infants With Punctate White Matter Damage

目的探讨扩散加权成像(DWI)在早期诊断早产儿局灶性脑白质损伤(punctate white matter damage,PWMD)及其预后的价值。资料与方法搜集PWMD早产儿39例资料。患儿均在生后两周内进行头部MR、DWI(b=1000s/mm2)扫描且被确诊为PWMD。随访患儿头部MRI及生长发育情况。观察患儿早期DWI上病灶的数量、形状、分布;观察随访期病灶演变及对临床预后的影响。结果早期DWI上PWMD病灶数量<3个13例,3～10个10例,>10个16例;早期DWI上病灶呈"簇"状22例("簇"状病灶组),呈"线"状11例(线状病灶组),呈混合型6例(混合型病灶组)。病灶分布只位于侧脑室旁者9例,只位于侧脑室后角旁者13例,位于半卵圆中心、侧脑室旁、后角、前角旁等部位者17例。随访0.6～22个月后,簇状病灶组22例头部MRI示病灶吸收消失,未见异常信号灶。20例智力发育指数(mental development index,MDI)>80,神经运动发育指数(psychomotor devel-opment index,PDI)>80,2例语言发育障碍,MDI<69,PDI>80;线状病灶组7例头部MRI出现侧脑室旁白质软化灶(periventricular leukomalacia,PVL),2例出现侧脑室后角变方、中央脑白质变薄等PVL后遗改变,2例轻度脑积水。MDI<50,PDI<50者5例,MDI<69,PDI<69者5例;混合型病灶组2例MRI示PVL,4例示PVL后遗症改变。结论DWI上簇状病灶多位于侧脑室或后角旁,数量<10,病灶易吸收消失,随访头部MRI及生长发育未见明显异常;线状及混合型病灶广泛分布,数量>10,病灶易演变成PVL及其后遗改变,临床多出现运动发育迟缓、认知障碍改变。DWI应作为筛查早产儿脑损伤的常用序列,并能帮助判断PWMD的预后。

Objective To evaluate the ability of diffusion weighted imaging （DWI） to early detect and diagnose the signs of punctate white matter damage （PWMD） in premature infants.Materials and Methods 39 cases of PWMD of premature infants were included in the study who were confirmed by early MRI and DWI within two weeks from delivery. Follow-up MRI and clinical development were performed after few months to assess the number,appearance and distribution of PWMD on DWI,the changes of signal intensity and their results on follow-up MRI were also evaluated.Results On DWI the number of lesions was 3 in 13 infants （13/39）,3-10 in 10 infants （10/39）,and 10 in 16 infants （16/39）. 22 infants （22/39） with lesions in clusters,11 infants （11/39） with linearly organized lesions and 6 infants （6/39） with mixed-type lesions were observed. There were lesions in periventricular （PV） body region with 9 infants （9/39）,in PV posterior region with 13 infants （13/39） and in centrum semiovale,PV body,PV anterior,PV posterior,posterior limbs of the internal capsule and thalami with 17 infants （17/39）.Time from the initial examination to the follow-up examination ranged from 0.6 to 22 months. 22 infants with lesions in clusters showed no abnormal intensity on follow-up MRI,20 infants with mental development index （MDI）80 and psychomotor development index （PDI）80,2 infants with language barrier. 9 infants with linearly organized lesions were defined as periventricular leukomalacia （PVL）,2 infants with hydrocephalus,5 infants with MDI 50 and PDI 50,5 infants with MDI69 and PDI 69.6 infants with mixed-type lesions were defined as PVL.Conclusion PWMD often disappear if there are few lesions （10 ） in clusters and located at PV body or PV posterior horn,there are no abnormalities on follow-up MRI. PWMD often change into PVL with linearly organized lesions or mixed-type lesions（10 ）,there are adverse developmental outcomes or motor problems. DWI should be used as routine sequence to diagnose and predict PWMD.