Dan Wu¹, Jun Lei², Jason Rosenzweig², Irina Burd², and Jiangyang Zhang^3
1Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States, ²Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Maryland, United States, ³Radiology, Johns Hopkins University School of Medicine, Maryland, United States

In vivo diffusion MRI (dMRI) of the embryonic mouse brain is extremely challenging due to the complex motion and the demand for high-resolution to resolve the early brain microstructures. We proposed a localized imaging technique to achieve 3D dMRI in a reduced field-of-view, using spatially selective excitation pulses. Motion was reduced with the fast imaging, and further corrected by navigator echoes and retrospective registration. We were able to delineate major white and gray matter structures in the normal at 0.2 mm isotropic resolution, and detect embryonic brain injury in a mouse model of intrauterine inflammation.

Xiaojie Wang¹, Colin Studholme², and Christopher D. Kroenke^1
1Oregon Health & Science University, Portland, Oregon, United States, ²University of Washington, Seattle, Washington, United States

Longitudinal in utero MRI was performed on monkey fetuses at gestation days 85, 110, and 135. High resolution T2-weighted volumes and fractional anisotropy (FA) volumes were reconstructed from multiple sets of turbo-spin-echo acquired T2W and spin-echo EPI acquired DWIs. Cerebral cortical surface area (SA), curvature and FA were computed using CARET software. Curvature and SA increase while FA decreases with gestation age. Analysis of changes in FA, SA, and surface curvature revealed that morphological differentiation of cerebral cortical neurons, thought to underlie FA changes, correlates with changes in cortical curvature but not surface area.

Anna I Blazejewska¹, Sharmishtaa Seshamani², Susan K McKown³, Jason S Caucutt³, Manjiri Dighe³, Christopher Gatenby³, and Colin Studholme^2
1BICG, University of Washington, Seattle, WA, United States, ²BICG, University of Washington, WA, United States, ³University of Washington, WA, United States

In this work, we examine an approach using one or more dual echo multi-slice acquisitions that are themselves then repeated and combined. Between-slice motion is then estimated and the multiple echoes combined, allowing 3D mapping of T2* values in the presence of fetal head motion. We applied the methods to a cohort of healthy fetuses from mid-gestation onwards. This importantly provides a full 3D image and extends previously published measurements below 26W into the 20-26W period where many clinical MRI’s are acquired after an earlier ultra-sound evaluation of pregnancy.

Parvaneh Adibpour^1,2, Ghislaine Dehaene-Lambertz^1,2, and Jessica Dubois^1,2
1Cognitive Neuroimaging Unit, INSERM, Gif-sur-Yvette, France, ²NeuroSpin, CEA, Gif-sur-Yvette, France

White matter myelination is a long-lasting process occurring at different times and speeds depending on bundles and underlying networks. Since it both impacts DTI parameters and accelerates the neural transmissions between brain regions, we investigated whether transverse diffusivity measured in the tracts conducting the functional information would explain the conduction speeds measured with event-related potentials better than age. By considering the visual and auditory networks of 6- to 22-week old infants, we analyzed early lateralized responses in relation to projection bundles, and the inter-hemispheric transfer of responses in relation to corpus callosum fibers while taking into account the age effects.

Adeoye Oyefiade¹, Stephanie Ameis^2,3, Nadia Scantlebury^1,2, Alexandra Decker², Kamila U Szulc², and Donald J Mabbott^1,2
1Psychology, The Hospital for Sick Children, Toronto, ON, Canada, ²Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada,³Child and Youth Mental Health, Center for Addiction and Mental Health, Toronto, Toronto, ON, Canada

Neural communication is facilitated by white matter (WM) comprised of both short and long-range tracts. Diffusion tensor imaging (DTI) has successfully described the developmental characteristics of long-range WM tracts. There remains a limited understanding of these characteristics in short-range tracts. Here, we used DTI and probabilistic tractography to reconstruct short-range white matter in a group of typically developing children and adolescents. DT-MR images were obtained for typically developing children and adolescents. Results indicate significant age-related changes in u-fibers across the brain with the exception of the occipital lobes. Future studies will investigate the relationship between these changes and cognitive function.

Can Wu^1,2, Samantha Schoeneman³, Amir Honarmand², Susanne Schnell², Michael Markl^1,2, and Ali Shaibani^2,3
1Biomedical Engineering, Northwestern University, Chicago, Illinois, United States, ²Radiology, Northwestern University, Chicago, Illinois, United States,³Medical Imaging, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, United States

The purpose of this study was to quantify both cerebral arterial inflow using 4D flow and cardiac outflow with 2D phase-contrast MRI and investigate the age dependence of changes in total cerebral arterial flow in relation to aortic flow in a cohort of 40 normal subjects with ages from 7 months to 60 years. The results demonstrated age-related changes in both cerebral and aortic blood flow as well as changes in their relationship, indicating the importance of age-controlled control groups for the detection of abnormal hemodynamics in neurovascular diseases (e.g. cerebral arteriovenous malformations, vein of Galen malformations, intracranial atherosclerotic disease).

Elaine H Lui^1,2, Jonathan Guntin³, Saad Jamil³, Ziqi Sun³, Ian C Atkinson³, and Keith R Thulborn^3
1Radiology, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia, ²Centre of Magnetic Resonance Research, University of Illinois Chicago, Chicago, Illinois, United States, ³Centre of Magnetic Resonance Research, University of Illinois Chicago, Illinois, United States

The age dependence of cell volume fraction (CVF) has been determined in normal human brain. CVF is derived from tissue sodium concentration (TSC) measured by quantitative sodium MRI at 9.4T using the flexible twisted projection sequence with 3-point calibration and the two-compartment model of tissue sodium distribution. Regional analysis provided descriptive statistics of CVF and voxel number for specified brain regions to use in a linear correlation analysis of their dependence on age. CVF remains stable across cognitively normal ageing despite progressive cerebral volume loss. This methodology may be useful for monitoring progression of neurodegenerative diseases prior to clinical manifestation.

Robert S Vorburger¹, Atul Narkhede¹, Yunglin Gazes¹, Vanessa A Guzman¹, Yaakov Stern^1,2, and Adam M Brickman^1,2
1Taub Institute, Columbia University, New York, New York, United States, ²Department of Neurology, Columbia University, New York, New York, United States

FLAIR and DTI have been widely used to investigate cerebral white matter changes of the aging brain. The relationship between parameters derived from the two techniques, such as white matter hyperintensities (WMH) and fractional anisotropy (FA), is still poorly understood. To investigate this relationship, a reference FA map from a sample of young subjects and a WMH probability map from a sample of elderly subjects was computed. Regions with a high FA value in the young brain show a significant lower WMH probability in the elderly brain, indicating that densely packed fiber tracts are less prone to develop WMH.

Udunna Anazodo^1,2, Kevin Shoemaker³, Neville Suskin⁴, Danny JJ Wang⁵, and Keith S St Lawrence^1,2
1Lawson Health Research Institute, London, Ontario, Canada, ²Medical Biophysics, Western University, London, Ontario, Canada, ³School of Kinesiology, Western University, London, Ontario, Canada, ⁴London Health Sciences Cardiology Rehabilitation Program, London, Ontario, Canada, ⁵University of California, Los Angeles, California, United States

The impact of cardiovascular disease on brain structure and function is not well known. In this study we present evidence of cortical thinning and cerebral hypoperfusion in brains of coronary artery disease patients including area often associated with cognitive function. Correlation of brain atrophy to hypoperfusion and decreased vascular dynamics, measured with cerebrovascular reactivity suggest that vascular disease can accelerate decline in brain structure and function.

Peiying Liu¹, Karen Rodrigue², Kristen Kennedy², Shin-Lei Peng¹, Yang Li¹, Michael Devous³, Denise Park², and Hanzhang Lu^1
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, ²Center for Vital Longevity, University of Texas at Dallas, Texas, United States, ³Avid Radiopharmaceuticals Inc, Texas, United States

Accumulation of -amyloid (A) protein in the brain is a key process in the pathogenesis of Alzheimer’s disease, but the relationship between A and vascular function in normal controls is unclear. In this work, we conducted a longitudinal study in healthy individuals at two time points 4-year apart. We found that A accumulation in the brain has a negative impact on cerebrovascular reactivity, and A accumulation may be the cause of cerebrovascular degeneration. We also found a positive correlation between Wave 1 A and Wave 2 CBF, suggesting neural compensatory processes may be present that result in elevated blood flow.