Early Folding Patterns and Asymmetries of the Normal Human Brain Detected from in Utero MRI

Abstract

Early cortical folding and the emergence of structural brain asymmetries have been previously analyzed by neuropathology as well as qualitative analysis of magnetic resonance imaging (MRI) of fetuses and preterm neonates. In this study, we present a dedicated image analysis framework and its application for the detection of folding patterns during the critical period for the formation of many primary sulci (20-28 gestational weeks). Using structural information from in utero MRI, we perform morphometric analysis of cortical plate surface development and modeling of early folding in the normal fetal brain. First, we identify regions of the fetal brain surface that undergo significant folding changes during this developmental period and provide precise temporal staging of these changes for each region of interest. Then, we highlight the emergence of interhemispheric structural asymmetries that may be related to future functional specialization of cortical areas. Our findings complement previous descriptions of early sulcogenesis based on neuropathology and qualitative evaluation of 2D in utero MRI by accurate spatial and temporal mapping of the emergence of individual sulci as well as structural brain asymmetries. The study provides the missing starting point for their developmental trajectories and extends our understanding of normal cortical folding.

Asymmetric Development of the Hippocampal Region Is Common: A Fetal MR Imaging Study

“…They did not mention the hippocampal sulcus in the report. The recent MR imaging study of fetuses in utero by Habas et al 21 also showed faster development of the right hemisphere, including the right parahippocampal gyrus. Electrophysiologic development is known to be slower in the left temporal lobe in healthy infants and children.…”

“…In the materials of Chi et al 20 and Garel et al, 9 the collateral sulcus was observed at the ages of 23 and 26 GW, respectively. The most recent MR imaging study by Habas et al 21 has shown that the collateral sulcus is formed around GW 24. The orientation of the collateral sulcus can tend toward a vertical or a horizontal axis, the latter orientation being the most common in adults.…”

Third Trimester Brain Growth in Preterm Infants Compared With In Utero Healthy Fetuses

“…Our findings suggest that even in the absence of structural brain injury, the developmental trajectory of the preterm brain is altered over the third trimester. Evidence of clinical 4 .01 * 14.17 ± 1.6 [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] 13.91 ± 2.7 [8][9][10][11][12][13][14][15][16][17][18][19][20] .66…”

Asymmetry within and around the human planum temporale is sexually dimorphic and influenced by genes involved in steroid hormone receptor activity

“…Although present to a degree in other primates (Gannon, Holloway, Broadfield, & Braun, 1998;Lyn et al, 2011), a population-level bias towards leftward PT asymmetry is pronounced in the human brain and is already visible in third trimester foetuses (Bossy, Godlewski, & Maurel, 1976). Various other studies have shown foetal and infant asymmetries in the perisylvian region, sylvian fissure, and superior temporal sulcus (Dubois, Benders, Cachia, et al, 2008, Dubois, Benders, Lazeyras, et al, 2010Habas et al, 2012;Kasprian et al, 2011;Li et al, 2013). These early developmental asymmetries clearly indicate a role for genetic mechanisms, but very few individual genes have so far been implicated in any aspect of lateralization of the human brain (Francks et al, 2007;Ocklenburg, Beste, & Gunturkun, 2013;Scerri et al, 2011;Sun et al, 2005;Sun & Walsh, 2006).…”