Evolution of Unilateral Perinatal Arterial Ischemic Stroke on Conventional and Diffusion-Weighted MR Imaging
Evolution of Unilateral Perinatal Arterial Ischemic Stroke on Conventional and Diffusion-Weighted MR Imaging
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DOI：
10.3174/ajnr.a1480
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发表时间：
2009-05-01
影响因子：
3.5
通讯作者：
Cowan, F. M.
中科院分区：
文献类型：
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作者：
Dudink, J.;Mercuri, E.;Cowan, F. M.
背景和目的：对围产期动脉缺血性卒中(PAIS)后常规和弥散加权磁共振成像(DWI)信号强度(SI)变化序列的了解有限，增加了确定PAIS发病时间的难度。我们假设在PAI后早期序列磁共振成像上看到的SI变化应该遵循类似的时间进程。本研究的目的是使用一种简单的分类方法来评估足月新生儿有症状的单侧PAIS的SI变化的时间进程，该分类可以从常规成像和弥散加权成像中直观地评估。材料和方法：本研究包括出生后第一个月内首次进行MR成像的36周妊娠合并单侧PAI的婴儿。对出生后3个月以内的所有后续扫描也进行了评估。对于常规MR成像扫描，使用视觉SI评分系统(-1=较低，0=相等，1=较高)与对侧大脑半球进行比较。结果：分析了21例足月儿的43次扫描结果，其中重度高信号组(HI)、中度高信号组(HI)、轻度高信号组(HI)和无高信号组(Non-HI)各43例。婴儿在常规T1和T2图像上SI的变化非常一致。皮质T1为低信号，T2为高信号，至第6天SIS逆转，可见皮质突起1~2个月。脑白质在前8-9天在T1为高信号，在T2为高信号持续2周，然后变为低信号。1周时丘脑和脑干可见远离梗死区的继发性SI改变，4周后可见萎缩。所有弥散加权成像均显示患侧大脑半球的高SI，至少持续到第4天，至第12天时降至等于或低于对侧大脑半球。结论：PAI后的SI变化模式在不同患者之间有显著的一致性，提示有症状的足月儿PAI发生在出生前的一段非常有限的时间内。
BACKGROUND AND PURPOSE: Knowledge of the sequence of signal-intensity (SI) changes on conventional and diffusion-weighted MR imaging (DWI) following perinatal arterial ischemic stroke (PAIS) is limited, adding to the difficulty in timing the onset of PAIS. We hypothesized that SI changes seen on early sequential MR imaging following PAIS should follow a similar time course. The aim of this study was to evaluate the time course of SI changes by using a simple classification that could be assessed visually from conventional imaging and DWI in term-born neonates with symptomatic unilateral PAIS.MATERIALS AND METHODS: Infants >= 36 weeks gestation with unilateral PAIS in the territory of a main cerebral artery with a first MR imaging performed within the first postnatal month were included in this study. All subsequent scans up to 3 months postnatal age were also evaluated. For the conventional MR imaging scans, a visual SI scoring system was used (-1 = lower, 0 = equal, 1 = higher) compared with the contralesional hemisphere. For the DWIs, SI of the infarcted tissue was classified into the 3 groups: 1) severe hyperintensity (HI), 2) moderate and mild HI, and 3) no HI.RESULTS: We analyzed 43 scans (mean age at first scanning, 4 days) from 21 term infants. Changes in SI on conventional T1 and T2 images were remarkably consistent among infants. The cortex was of low SI on T1 and high SI on T2 until day 6 when SIs reversed and cortical highlighting was seen for 1-2 months. The white matter was high SI on T1 in the first 8-9 days and on T2 for >2 weeks before becoming low SI. Secondary SI changes remote from the infarction were seen in the thalamus and brain stem in the first week, and atrophy was seen after 4 weeks. All DWIs showed high SI of the affected region until at least day 4, which fell to equal or below that of the contralesional hemisphere by day 12.CONCLUSIONS: The pattern of SI change on conventional imaging and DWI following PAIS was remarkably consistent among patients, suggesting that PAIS in symptomatic term-born infants occurs within a very limited timeframe around birth.