Hunter R Underhill^1,2 and Gary Hedlund^2
1Pediatrics, University of Utah, Salt Lake City, UT, United States, ²Radiology, University of Utah, Salt Lake City, UT, United States

Fast bound-pool fraction imaging (FBFI) is a quantitative MRI technique validated with histology to measure whole-brain, voxel-based myelin density. In this study, FBFI was translated to a whole-body 3T clinical scanner using only standard preset sequences without modifications to measure myelin density in the developing pediatric brain via a time-efficient methodology (<7 min). We found that FBFI effectively quantifies myelin density during normal development. Progressive myelination identified in the posterior white matter corresponded strongly to a bounded exponential growth curve. Quantification of myelin density with FBFI in pediatric patients may improve detection of delayed or altered myelination.

Longchuan Li^1,2, Sarah Shultz¹, Xiaoping Hu², Ami Klin¹, and Warren Jones^1
1Marcus Autism Center, Emory University, Atlanta, GA, United States, ²Biomedical Imaging Technology Center, Emory University, Atlanta, GA, United States

We used diffusion tractography and network theory to examine the organizational development of the brain in typical infants in their first 6 months of life. Data were longitudinally sampled at randomized time points between birth and 6 months and collected on a Siemens 3T TIM Trio system with 32-channel coil using multiband techniques. We found that network-based metrics may reveal unique information in the organizational principles of the brain and its development that is impossible with conventional methods focusing on specific pathways and regions, demonstrating the usefulness of the approach in studying early typical brain development and its disruptions.

Peiying Liu¹, Ying Qi², Zixuan Lin¹, Xuna Zhao³, Qiyong Guo², Xiaoming Wang², and Hanzhang Lu^1
1Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ²Shengjing Hospital of China Medical University, Shenyang, China, People's Republic of, ³Philips Healthcare, Beijing, China, People's Republic of

Knowledge of CBF in neonates or infants may provide valuable information in many pathological conditions. When applied to very young children, CBF mapping using arterial-spin-labeling (ASL) MRI suffers from low SNR and poor quantification, whereas phase-contrast (PC) MRI may provide reliable estimation of global CBF. Therefore, this study aim to 1) provide a set of age-specific PC-MRI protocols for CBF quantification in children under 1.5 years old; 2) establish typical arterial flow velocity in children at this age which could guide future ASL efforts in labeling pulse optimization; 3) report how CBF changes during this early stage of life.

Minhui Ouyang¹, Tina Jeon¹, Jennifer Muller¹, Virendra Mishra², Haixiao Du³, Yu Wang³, Yun Peng⁴, Bo Hong⁵, and Hao Huang^1,6
1Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, United States, ²Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States, ³Department of Electronic Engineering, Tsinghua University, Beijing, China, People's Republic of, ⁴Department of Radiology, Beijing Children's Hospital, Capital Medical University, Beijing, China, People's Republic of, ⁵Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of, ⁶Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States

Disturbance of precisely balanced strengthening of certain axons and pruning of others in developmental human brains is associated with mental disorders such as autism and schizophrenia. To characterize this balance, we defined a cortical connectivity maturation index (CCMI) derived from short-range association tracts traced with diffusion MRI tractography. The brain CCMI values were measured with diffusion MRI and T₁-weighted datasets of 21 healthy subjects with age of 2-25 years. CCMI in all cortical regions decreased in early developmental stage and increased later, yet with distinctive trajectories. The observed CCMI dynamics may be underlaid by heterogeneous pruning among cortical regions.

Sean Deoni^1,2, Holly Dirks², Jonathan O'Muircheartaigh³, and Douglas C Dean^4
1CHILD Lab, Children's Hospital, Colorado, Aurora, CO, United States, ²Advanced Baby Imaging Lab, Brown University, Providence, RI, United States, ³Neuroimaging, King's College, London, London, United Kingdom, ⁴Waisman Lab for Brain Imaging and Behavior, University of Wisconsin Madison, Madison, WI, United States

It is well established that family socioeconomic status (SES), related to parental education level, occupation, and income, is associated with differences in offspring educational outcomes and cognitive abilities.  However, while brain imaging studies in older children have revealed altered brain structure associated with SES, the influence of SES on infant and childhood brain development remain unclear.  Here we investigated longitudinal trajectories of brain and cognitive development in a large cohort of typically-developing children from 2 months to 6 years of age.  Results reveal diverging developmental trends associated with parental education (PE) level even when controlling for common confounds.

Ning Ning¹, Peng Wu², Xianjun Li³, Yajie Hu³, Weishan Zhang¹, Lei Zhang¹, Sung-Min Gho⁴, Dong-Hyun Kim⁴, Hua Guo², and Jian Yang^1,3
1Department of Diagnostic Radiology, the First Affiliated Hospital of Xi’an Jiaotong University, Xi'an, China, People's Republic of, ²Department of Biomedical Engineering, Tsinghua University, Beijing, China, People's Republic of, ³Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China, People's Republic of, ⁴Department of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea, Republic of

To observe the age-related susceptibility changes in the deep gray nuclei and assess the superiority of the quantitative susceptibility mapping(QSM) and effective transverse relaxation rate(R2*) for quantifying the iron deposits in children. 87 subjects(1M-6Y) were enrolled. The susceptibility in QSM and R2* values exhibited positive correlations with age and the reference iron concentrations calculated using an empirical equation. The correlation of the susceptibility with the iron is higher than the R2* with it. QSM may provide a more promising and reliable tool for assessment of iron content in children’s deep gray nuclei, even in the regions with lower iron content.

Frédéric Grouiller¹, Alexandra Adam-Darqué², Russia Ha-Vinh Leuchter², Petra S Hüppi², and François Lazeyras^1
1Department of Radiology and Medical Informatics, University of Geneva, Geneva, Switzerland, ²Division of Development and Growth, Department of Pediatrics, University of Geneva, Geneva, Switzerland

The aim of this study is to better characterize the habituation effect of sustained odorant stimulation and to investigate if this effect is already present in newborns. Olfactory fMRI was acquired in adults and newborns using a 20s block design. After modelling habituation, activations in the primary and secondary olfactory cortices were observed in adults and newborns. Habituation effect to sustained odorant stimulation was strong in adults but unseen in the newborns. This study shows that the olfactory cortex of newborns is highly functional soon after birth and that the habituation effect is not observed in newborns compared to adults.

Yuan Xiao^1,2, Lili Yang², Lu Liu¹, Xin Gao¹, Bo Tao¹, Min Wu¹, Yuchuan Fu², Meimei Du², Zhihan Yan², and Su Lui^1,2
1Department of Radiology, HMRRC, West China Hospital of Sichuan University, Chengdu, China, People's Republic of, ²Department of Radiology, The Second Affiliated Hospital & Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China, People's Republic of

This study provided the first empirical evidence of larger gray matter volume in left-behind children than comparison children who lived in the nuclear family, especially in emotional circuit, suggesting the early parental care would affect the brain development of gray matter rather than white matter.

Eliza Orasanu¹, Andrew Melbourne¹, Zach Eaton-Rosen¹, David Atkinson², Joshua Lawan³, Joanne Beckmann⁴, Neil Marlow⁴, and Sebastien Ourselin^1
1Translational Imaging Group, Centre for Medical Image Computing, University College London, London, United Kingdom, ²University College London, London, United Kingdom, ³University College Hospital, London, United Kingdom, ⁴Institute for Women's Health, University College London, London, United Kingdom

Alterations of thalamic structures may cause disruptions in thalamic-cortical-thalamic circuitry and affect cognition. In this work we present a local shape analysis of the thalamus in extremely preterm born young adults when compared to their term born peers. We perform a groupwise shape analysis after spectral matching registration. After correcting for gender and thalamic volume, it resulted that the anterior and superior thalamic regions, connected to regions responsible for executive function, working memory, language and verbal memory, show most shape variations.

Rosita Shishegar^1,2, Shreya Rana³, Mary Tolcos³, David W. Walker³, and Leigh A. Johnston^1,4
1Dept. Electrical & Electronic Engineering, University of Melbourne, Melbourne, Australia, ²NICTA Victoria Research Laboratory, Melbourne, Australia, ³The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Melbourne, Australia, ⁴Florey Institute of Neuroscience and Mental Health, Melbourne, Australia

Segmentation of the developing cortical plate from MRI data of the fetal brain is highly challenging due to partial volume effects, low contrast and heterogeneous maturation caused by ongoing myelination processes. We present a new atlas-free method for segmenting the boundary between the cortical plate and subplate in fetal brains, by exploiting diffusion-weighted imaging cues. The accuracy of the segmentation algorithm is demonstrated by application to fetal sheep brain MRI data.