Normal Growth, Sexual Dimorphism, and Lateral Asymmetries at Fetal Brain MRI

• DOI: 10.1148/radiol.211222
• Publication Date: 2021-12-21T15:00:01Z
• Authors: Fedel Machado-Rivas; Jasmine Gandhi; Jungwhan John Choi; Clemente Velasco-...; Onur Afacan; Simon K. Warfield; Ali Gholipour; Camilo Jaimes
• Keywords: Caudate nucleus

Background Tools in image reconstruction, motion correction, and segmentation have enabled the accurate volumetric characterization of fetal brain growth at MRI. Purpose To evaluate intracranial structures healthy fetuses, accounting for gestational age (GA), sex, laterality with use a spatiotemporal MRI atlas development. Materials Methods T2-weighted 3.0-T half-Fourier acquired single-shot turbo spin-echo sequence was performed fetuses from prospectively recruited pregnant volunteers March 2013 to May 2019. A previously validated section-to-volume reconstruction algorithm used generate intensity-normalized superresolution three-dimensional volumes that were registered 28 anatomic regions interest. Atlas-based manually refined. Labels included bilateral hippocampus, amygdala, caudate nucleus, lentiform thalamus, lateral ventricle, cerebellum, cortical plate, hemispheric white matter, internal capsule, ganglionic eminence, ventricular zone, corpus callosum, brainstem, hippocampal commissure, extra-axial cerebrospinal fluid. For younger than 31 weeks GA, subplate intermediate zones delineated. linear regression analysis determine weekly age-related change adjusted sex laterality. Results The final analytic sample consisted 122 scans 98 (mean 29 ± 5 [range, 20–38 weeks]). All had significant volume increasing GA (P < .001). Weekly individual parenchyma ranged 2.0% (95% CI: 0.9, 3.1; P .001) commissure 19.4% 18.7, 20.1; cerebellum. largest sex-related differences 22.1% higher male ventricles 10.9, 34.4; There rightward asymmetry 15.6% hippocampus 14.2, 17.2; leftward 8.1% 3.7, 12.2; Conclusion With atlas, showed complex trajectories dependent on structure, age, © RSNA, 2021 Online supplemental material is available this article. See also editorial by Rollins issue.