Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, University 317-1, Daemyungdong, Namku, Taegu 705-717, Republic of Korea.
Neuroradiology. 2012 Sep;54(9):997-1005. doi: 10.1007/s00234-012-1042-8. Epub 2012 May 6.
Preterm children with thinning of the corpus callosum (CC) frequently achieve poor neurodevelopmental outcomes despite the absence of a definite brain lesion. Here, the authors compared the microstructural characteristics of the CC in preterm and full-term children using diffusion tensor imaging (DTI).
Twenty-two preterm children with no definite focal lesion but with thinning of the CC by conventional magnetic resonance imaging and 23 age-matched full-term children were investigated by DTI. CCs were subdivided into genu, rostral body, body, isthmus, and splenium, and voxel counts (VC), fractional anisotropies (FA), and apparent diffusion coefficients (ADC) were measured in each subdivision. Eleven preterm and 11 age-matched full-term subjects underwent follow-up scanning and interval changes in these parameters for each subdivision were compared.
VC and FA were significantly lower in the preterm group than in the full-term group, particularly in the isthmus. Furthermore, incremental changes in VC and FA were significantly smaller in the preterm group. Differences in maturation between the two groups were more pronounced with age in all subdivisions except the splenium. At all ages, noticeable FA differences between the two groups were observed in the isthmus. For white matter tracts, the preterm group displayed lower FA and fiber number, higher ADC values than the term group.
The present study shows that thinning of the CC is correlated with lower FA value and that it is more pronounced in preterm children. In addition, the isthmus was found to be the most vulnerable subdivision in preterm children.
尽管没有明确的脑部病变,但存在胼胝体变薄的早产儿经常出现神经发育不良的后果。在此,作者使用弥散张量成像(DTI)比较了早产儿和足月儿的胼胝体的微观结构特征。
研究共纳入 22 名早产儿,他们的常规磁共振成像显示胼胝体变薄,但没有明确的局灶性病变,同时还纳入了 23 名年龄匹配的足月儿作为对照组。将胼胝体分为膝部、体部、连合部、压部和嘴部,分别测量各部位的体素计数(VC)、各向异性分数(FA)和表观扩散系数(ADC)。11 名早产儿和 11 名年龄匹配的足月儿进行了随访扫描,比较了各部位参数的间隔变化。
与足月儿相比,早产儿的 VC 和 FA 值明显降低,尤其是连合部。此外,早产儿各部位的 VC 和 FA 值的递增变化明显更小。除压部外,两组在所有部位的成熟度差异均随年龄的增加而增大。在所有年龄段,早产儿与足月儿的连合部 FA 值差异明显。对于白质束,早产儿的 FA 值和纤维数量低于足月儿,ADC 值高于足月儿。
本研究表明,胼胝体变薄与 FA 值降低有关,早产儿更为明显。此外,研究发现早产儿的连合部是最脆弱的部位。