Liauw L, van der Grond J, van den Berg-Huysmans A A, Laan L A E M, van Buchem M A, van Wezel-Meijler G
Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
AJNR Am J Neuroradiol. 2008 Oct;29(9):1789-94. doi: 10.3174/ajnr.A1188. Epub 2008 Jul 3.
It has previously been demonstrated that comparison of signal intensity (SI) between selected brain structures on T1-weighted images enables distinction between the absence or presence of hypoxic-ischemic (HI) brain injury in young infants. The aim of the present study was to assess whether this method of brain structure T1-weighted SI comparison also enables prediction of outcome.
Survivors of a group of 57 children with neonatal HI encephalopathy (HIE) grade 2 or 3 according to Sarnat and Sarnat and controls who underwent neonatal MR imaging were retrospectively assigned to 1 of 3 outcome groups at 5 years of age, depending on developmental outcome: 1) normal, 2) mildly abnormal, and 3) definitely abnormal. Gestational age was not significantly different between the HIE group (range, 35 + 5-42 + 5 weeks; mean, 39 + 4 weeks) and control group (range, 35 + 0-42 + 1 weeks; mean, 39 + 2 weeks). We calculated the predictive values of the neonatal clinical HIE classification according to Sarnat and Sarnat for outcome (neonatal death and developmental outcome in survivors). We assessed which brain structure T1-weighted SI comparison scored best for outcome prediction. Predictive values of that comparison for outcome were calculated for the entire group and for the HIE grade 2 group only, a patient group with highly variable outcome.
Of the 57 children, 6 died. Outcome group 1 consisted of 31; group 2, of 14; and group 3, of 6 children. The positive predictive value of the neonatal clinical classification for adverse outcome (outcome group 3 and death) was 52%; and negative predictive value, 100%. These were respectively 45% and 0% in children with HIE grade 2. Of all brain structure T1-weighted SI comparisons, that of the posterior limb of the internal capsule versus the posterolateral putamen scored best for outcome prediction. The positive predictive value for adverse outcome was 69%; and negative predictive value, 98%. In children with HIE grade 2, the positive predictive value and negative predictive value for adverse outcome were 67% and 88%.
Brain structure T1-weighted SI comparisons are helpful to predict outcome in (near) term neonates with HIE. This finding adds to the current knowledge and clinical practice. If the SI in the posterolateral putamen is less than the SI in the posterior limb of the internal capsule, favorable outcome is very likely, whereas if the SI in the posterolateral putamen is equal to or greater than the SI in the posterior limb of the internal capsule, adverse outcome is very likely. In neonates with HIE grade 2 according to Sarnat and Sarnat, prediction of outcome is substantially improved by using these brain structure T1-weighted SI comparisons.
先前的研究已表明，通过比较T1加权图像上选定脑结构之间的信号强度（SI），能够区分婴幼儿是否存在缺氧缺血性（HI）脑损伤。本研究的目的是评估这种脑结构T1加权SI比较方法是否也能预测预后。
对一组57例根据萨纳特和萨纳特分级为2级或3级的新生儿HI脑病（HIE）患儿的幸存者以及接受新生儿磁共振成像的对照组进行回顾性研究，根据5岁时的发育结局将其分为3个预后组之一：1）正常；2）轻度异常；3）明显异常。HIE组（范围为35⁺⁵ - 42⁺⁵周；平均为39⁺⁴周）与对照组（范围为35⁺⁰ - 42⁺¹周；平均为39⁺²周）的胎龄无显著差异。我们计算了根据萨纳特和萨纳特分级的新生儿临床HIE分类对预后（新生儿死亡和幸存者的发育结局）的预测价值。我们评估了哪种脑结构T1加权SI比较对预后预测的评分最佳。计算了该比较对整个组以及仅对HIE 2级组（一个预后差异很大的患者组）的预后预测价值。
57例患儿中，6例死亡。预后组1有31例；组2有14例；组3有6例患儿。新生儿临床分类对不良预后（预后组3和死亡）的阳性预测值为52%；阴性预测值为100%。HIE 2级患儿的这些值分别为45%和0%。在所有脑结构T1加权SI比较中，内囊后肢与壳核后外侧之间的比较对预后预测的评分最佳。不良预后的阳性预测值为69%；阴性预测值为98%。在HIE 2级患儿中，不良预后的阳性预测值和阴性预测值分别为67%和88%。
脑结构T1加权SI比较有助于预测（近）足月HIE新生儿的预后。这一发现增加了当前的知识和临床实践内容。如果壳核后外侧的SI低于内囊后肢的SI，则很可能有良好的预后，而如果壳核后外侧的SI等于或高于内囊后肢的SI，则很可能有不良预后。对于根据萨纳特和萨纳特分级为HIE 2级的新生儿，使用这些脑结构T1加权SI比较可显著改善预后预测。
