PDF(Pubmed)
Abstract：
Little information is available on the magnetic resonance imaging (MRI) determination of the hippocampal formation (HF) during the perinatal period. However, this exploration is increasingly used, which requires defining visible HF landmarks on MRI images, validated through histological analysis. This study aims to provide a protocol to identify HF landmarks on MRI images, followed by histological validation through serial sections of the temporal lobe of the samples examined, to assess the longitudinal extent of the hippocampus during the perinatal period. We examined ex vivo MRI images from nine infant control brain samples. Histological validation of the hippocampal formation MRI images was obtained through serial sectioning and examination of Nissl-stained sections at 250 μm intervals along the entire length of the hippocampal formation. Up to six landmarks were identified both in MRI images and the serial histological sections. Proceeding in an anterior to posterior (rostrocaudal) direction, these were as follows: 1) the limen insulae (fronto-temporal junction); 2) the beginning of the amygdaloid complex; 3) the beginning of the lateral ventricle; 4) the caudal limit of the uncus, indicated by the start of the lateral geniculate nucleus (at the level of the gyrus intralimbicus); 5) the end of the lateral geniculate nucleus (beginning of the pulvinar); and 6) the beginning of the fornix. After histological validation of each of these landmarks, the full longitudinal length of the hippocampal formation and distances between landmarks were calculated. No statistically significant differences were found in total length or between landmarks. While the HF is anatomically organized at birth, its annotation is particularly challenging to perform. The histological validation of HF landmarks allows a better understanding of MRI images. The proposed protocol could be useful to assess MRI hippocampal quantification in children and possible variations due to different neurological diseases.
摘要：
关于围产期海马结构（HF）的磁共振成像（MRI）测定的信息很少。然而,这种探索被越来越多地使用，这需要在MRI图像上定义可见的HF标志，通过组织学分析验证。这项研究旨在提供一种协议，以识别MRI图像上的HF标志，然后通过检查样本颞叶的连续切片进行组织学验证，评估围产期海马的纵向范围。我们检查了来自9个婴儿对照脑样本的离体MRI图像。通过沿海马结构的整个长度以250μm的间隔对Nissl染色的切片进行连续切片和检查，获得了海马结构MRI图像的组织学验证。在MRI图像和连续组织学切片中最多识别出六个标志。在前向后(rostrocautal)方向进行，这些如下:1)利蒙岛叶(额-颞部)；2)杏仁核复合体的开始；3)侧脑室的开始；4)索的尾部界限，由外侧膝状核的开始（在回的水平处）指示；5）外侧膝状核的末端（髓核的开始）；和6）穹窿的开始。在对每个地标进行组织学验证后，计算海马结构的整个纵向长度和标志之间的距离。总长度或地标之间未发现统计学上的显着差异。虽然HF在出生时是解剖学组织的，它的注释执行起来特别具有挑战性。HF标志的组织学验证可以更好地理解MRI图像。所提出的方案可用于评估儿童的MRI海马定量以及由于不同神经系统疾病而引起的可能变化。
