Martin E, Kikinis R, Zuerrer M, Boesch C, Briner J, Kewitz G, Kaelin P
Department of Pediatrics, University of Zurich, Switzerland.
J Comput Assist Tomogr. 1988 Nov-Dec;12(6):917-22. doi: 10.1097/00004728-198811000-00002.
The differentiation of the telencephalon (TC) gyri and the myelination of TC and diencephalon were analyzed quantitatively in 50 children, 32-240 weeks' postconceptional age (PCA). For this purpose, a four-stage grading system was developed by correlating magnetic resonance images from age-matched postmortem brains with subsequently prepared myelin-stained macroslices. Gyration and myelination progressed in a occipito-rostral direction. Stages 3 and 4 myelination were recognized earlier on T1-weighted images [spin echo (SE) 500/30] than on T2-weighted images (SE 3,000/120). However, long repetition time/echo time sequences yielded better contrast and allowed finer differentiation between myelinated and nonmyelinated structures. At term, the posterior limb of the internal capsule was generally myelinated (stage 2), whereas in 50% of the children, myelin appeared in the TC between 55 and 65 weeks' PCA, e.g., between 3 and 6 months postnatally. The morphological differentiation of the brain surface preceded the biochemical maturation (myelination) by an average of 12 months. Applying such a grading system to a larger population will help establish normal standards for brain maturation and a "brain age" scale during the first 4 years of life.
对50名孕龄32 - 240周的儿童的端脑（TC）脑回分化以及端脑和间脑的髓鞘形成进行了定量分析。为此，通过将年龄匹配的死后大脑的磁共振图像与随后制备的髓鞘染色大切片相关联，开发了一种四阶段分级系统。脑回形成和髓鞘形成沿枕 - 嘴侧方向进展。在T1加权图像[自旋回波（SE）500/30]上比在T2加权图像（SE 3,000/120）上更早识别出3期和4期髓鞘形成。然而，长重复时间/回波时间序列产生了更好的对比度，并允许在髓鞘化和非髓鞘化结构之间进行更精细的区分。足月时，内囊后肢通常已髓鞘化（2期），而在50%的儿童中，在孕龄55至65周时，即出生后3至6个月之间，端脑出现髓鞘。脑表面的形态分化比生化成熟（髓鞘形成）平均提前12个月。将这样的分级系统应用于更大的人群将有助于建立生命最初4年期间脑成熟的正常标准和“脑龄”量表。
