Department of Neurology and Neurosurgery, McGill University, Montreal Neurological Institute, 3801 University Street, Montreal, Quebec, Canada H3A 2B4.
Department of Psychology, McGill University, 2001 McGill College, Montreal, Quebec, Canada H3A 1G1.
Cereb Cortex. 2020 Mar 14;30(3):1586-1602. doi: 10.1093/cercor/bhz189.
The horizontal ascending ramus of the lateral fissure (half) is a characteristic sulcus of the ventrolateral frontal cortex that forms the morphological boundary between the pars triangularis and the pars orbitalis of the inferior frontal gyrus. The present study examined the morphology of this sulcus to provide a means of identifying it accurately with magnetic resonance imaging (MRI). Voxels within the half were labeled in 50 in vivo MRI volumes (1.5 T) that had been linearly registered to the Montreal Neurological Institute stereotaxic space and the morphology of the half was categorized based on relations with neighboring sulci. The spatial variability and extent of the half were then quantified across subjects using volumetric (MINC Toolkit) and surface (FreeSurfer) spatial probability maps. The half could be identified in 95% of hemispheres, and the main morphological patterns were classified into three categories: Types I, II, and III. There were no statistically significant interhemispheric differences in the frequency of the half or its morphological patterns. Understanding the details of the sulcal morphology of this ventrolateral region is critical for an accurate interpretation of the location of activation peaks generated in functional neuroimaging studies investigating language, working memory, and other cognitive processes.
外侧裂水平升支（半）是外侧额皮质的特征性脑沟，它构成了额下回三角部和眶部之间的形态学边界。本研究检查了该脑沟的形态，以便通过磁共振成像（MRI）准确识别。在 50 个体内 MRI 容积（1.5T）中对半进行了体素标记，这些容积已经线性注册到蒙特利尔神经学研究所的立体空间，并且根据与相邻脑沟的关系对半的形态进行了分类。然后使用容积（MINC 工具包）和表面（FreeSurfer）空间概率图在受试者之间量化半的空间变异性和范围。半可以在 95%的半球中识别，主要的形态模式分为三类：I 型、II 型和 III 型。半的出现频率及其形态模式在半球间没有统计学上的显著差异。了解这个外侧区域脑沟形态的细节对于准确解释在语言、工作记忆和其他认知过程的功能神经影像学研究中生成的激活峰值的位置至关重要。
