Sie L T, van der Knaap M S, van Wezel-Meijler G, Valk J
Department of Child Neurology, Free University Hospital, Amsterdam, The Netherlands.
Neuropediatrics. 1997 Apr;28(2):97-105. doi: 10.1055/s-2007-973680.
A study was performed in 48 neurologically normal preterm and term-born infants, with a postconceptional age at MRI varying between 30 2/7 and 46 weeks and a mean age of 34 2/7 weeks. The purpose of the study was to determine the normal progress of myelination on MRI in that age range. T1- and T2-weighted images of the brain were assessed for changes in signal intensity of white matter relative to gray matter. Multiple sites in the brainstem, cerebellum and cerebral hemispheres were assessed separately. The findings were correlated with the ages of the infants. As judged from relative signal intensities, myelin was present at the post-conceptional age of 30-34 weeks in the following structures: tegmentum pontis (in particular medial lemniscus), superior and inferior colliculi, decussation of the superior cerebellar peduncles, crura cerebri, ventrolateral thalamus, lateral globus pallidus, dorsolateral putamen, dentate nucleus, middle and superior cerebellar peduncles, vermis cerebelli, cortex bordering the central sulcus and hippocampus. Little progress in myelination was noticed up to the post-conceptional age of 46 weeks. Between 34 and 46 weeks, myelin appeared in the lateral part of the posterior limb of the internal capsule and in the central part of the corona radiata and became more prominently visible in the cortex bordering the central sulcus.
对48名神经功能正常的早产和足月出生婴儿进行了一项研究，这些婴儿在进行MRI检查时的孕龄在30又2/7至46周之间，平均年龄为34又2/7周。该研究的目的是确定该年龄范围内MRI上髓鞘形成的正常进展情况。评估了大脑的T1加权和T2加权图像中白质相对于灰质的信号强度变化。分别对脑干、小脑和大脑半球的多个部位进行了评估。研究结果与婴儿的年龄相关。从相对信号强度判断，在孕龄30 - 34周时，以下结构中存在髓鞘：脑桥被盖（特别是内侧丘系）、上丘和下丘、小脑上脚交叉、大脑脚、腹外侧丘脑、外侧苍白球、背外侧壳核、齿状核、小脑中小脚、小脑蚓部、中央沟周围皮质和海马体。直到孕龄46周，髓鞘形成进展甚微。在34至46周之间，髓鞘出现在内囊后肢的外侧部分和放射冠的中央部分，并在中央沟周围皮质中变得更加明显可见。
