Bing Zhang #¹, Chenchen Yan #¹, Ming Li¹, Huiting Wang¹, Zuzana Nedelska², Tong Ru³, Zhiqun Wang³, Jie Li³, Jian Yang⁴, Yali Hu*³, and Bin Zhu*^1
1Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China, ²Memory Disorders Clinic,Department of Neurology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Czech Republic, ³Department of Gynaecology and Obstetrics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China, ⁴Department of Radiology, The First Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, China

We aimed to examine the white matter development and small-world networks in 150 fetal brains across the different gestational weeks using sBTFE on MRI. The bilateral prefrontal signal intensity during gestational week 21-23 was lower than other subplate zones, consistent with the germinal matrix being present that region at that time. The lower degree of the connection pattern in brain at gestational week 25 could be due to the unsynchronized cellular migration within brain regions. And the similar pattern of the small-world properties between gestational weeks 28 and 33-39 indicated the fetal brain was maturating after gestational week 28.

András Jakab¹, Gregor Kasprian², Ernst Schwartz², Veronika Schöpf³, Daniela Prayer², and Georg Langs^1,4
1CIR Lab, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, ²Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, ³Institute for Psychology, University of Graz, Graz, Austria, ⁴Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, Cambridge, MA, United States

We utilized prenatal diffusion tensor imaging to map the globally altered structural brain connectivity in second and third trimester fetuses with corpus callosum agenesis. We have shown by connectome-level tractography that callosal agenesis manifests in excessive structural connectivity, which constantly intensifies during gestation. Our results indicate that misguided axons form aberrant antero-posteriorly running pathways not only adjacent to the median surface of the hemispheres, but distributed across the lateral parts of the convexity.

Dafnis Batalle¹, Emer J Hughes¹, Hui Zhang², Jaques-Donald Tournier¹, Nora Tusor¹, Paul Aljabar¹, Daniel C Alexander², Joseph V Hajnal¹, A David Edwards¹, and Serena J Counsell^1
1Centre for the Developing Brain, King's College London, London, United Kingdom, ²Computer Science & Centre for Medical Image Computing, University College London, London, United Kingdom

In this study, we used neurite orientation dispersion and density imaging (NODDI) parameters (neurite density index and orientation dispersion index) in combination with high angular resolution diffusion imaging (HARDI) tractography to assess the evolution of brain connectivity during very early infancy (29-45 weeks post menstrual age, PMA), exploiting the versatility of network analysis. We compared the results with those obtained using classical stream count (SC) and fractional anisotropy (FA) as connectivity weights. The results indicated a significant correlation of network features weighted with NODDI parameters and PMA, while SC and FA features did not show any significant correlation.

Magdalena Sokolska¹, Cristina Uria-Avellanal², M. Jorge Cardoso³, Maïa Proisy², Alan Bainbridge⁴, Sebastien Ourselin³, David Thomas¹, Nicola Robertson², and Xavier Golay^1
1UCL Institute of Neurology, London, United Kingdom, ²UCL Institute for Women's Health, United Kingdom, ³Centre for Medical Image Computing, UCL, United Kingdom, ⁴UCH Medical Physics and Bioengineering, United Kingdom

Perinatal hypoxia-ischemia (HI) can cause catastrophic alteration of brain metabolism and physiology, resulting in neonatal encephalopathy. Metabolic changes detected using magnetic resonance spectroscopy (MRS) have been used as a reliable predictor of clinical outcome. Abnormalities in cerebral blood flow (CBF), reflecting cerebral physiology, have also been linked to HI. The aim of this study was to develop an automated framework for regional analysis of CBF and to investigate the added value of combining thalamic MRS with detailed regional CBF analysis for the inclusion of ASL as a potential biomarker of outcome in HIE.

Wai Yen Loh^1,2, Deanne K Thompson^1,2, Jeanie LY Cheong^1,3, Alicia J Spittle^1,3, Jian Chen^1,4, Katherine J Lee^1,3, Terrie E Inder⁵, Alan Connelly^2,3, Lex W Doyle^1,3, and Peter J Anderson^1,3
1Murdoch Childrens Research Institute, Melbourne, Victoria, Australia, ²Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia,³University of Melbourne, Melbourne, Victoria, Australia, ⁴Monash University, Melbourne, Victoria, Australia, ⁵Brigham and Women's Hospital, Boston, Massachusetts, United States

Very preterm survivors (born <32 weeks’ gestation) experience motor and cognitive impairments. The basal ganglia and thalamus are key relay structures within the brain that modulate motor control and cognition. This study segmented the basal ganglia (accumbens, caudate, pallidum and putamen) and thalamus in 154 very preterm and 36 term children at age 7 years, using T1 images. Very preterm children had reduced pallidal and thalamic volumes compared with controls. Volumes in several of these relay structures were associated with motor function and IQ in very preterm children. This study contributes towards understanding the underlying motor and cognitive deficits observed in very preterm children.

Nicolaas AJ Puts^1,2, Ashley D. Harris^1,2, Mark Tommerdahl³, Peter B. Barker^1,2, Stewart H. Mostofsky^4,5, and Richard A. Edden^1,2
1Russell H. Morgan Dept. of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, United States, ²F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, United States, ³Dept. of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States, ⁴Dept. of Neurology, Johns Hopkins University, Baltimore, Maryland, United States, ⁵Center for Neurodevelopmental and Imaging Research, Kennedy Krieger Institute, Baltimore, Maryland, United States

Children with ASD often suffer from sensory impairments, which may be linked to GABAergic dysfunction. Using MM-suppressed GABA-edited and tactile psychophyics, we find that reduced GABA concentration is associated with ASD severity, and that ASD severity is linked to worse sensory performance. Furthermore, associations between GABA and sensory performance exist in healthy children, but not children with ASD. Our data suggest that GABAergic impairments are linked to sensory impairments in ASD. A better understanding of these mechanisms might allow for future therapies to alleviate these symptoms.

Amanda Elton¹ and Wei Gao^1,2
1Biomedical Research Imaging Center, UNC Chapel Hill, Chapel Hill, North Carolina, United States, ²Radiology, UNC Chapel Hill, Chapel Hill, North Carolina, United States

Autism spectrum disorders (ASD) are characterized by social interaction deficits and repetitive or stereotyped behaviors, with undetermined neural mechanisms. Guided by an increased recognition of the dimensional characteristics of ASD symptoms, we sought to delineate the categorical and dimensional neural mechanisms of ASD using network-level functional connectivity measures from resting-state fMRI. Our results support the existence of dimensional connectivity-behavioral relationships related to ASD symptoms. We also identified categorical differences in connectivity strength for ASD children that were independent of dimensional relationships, in addition to categorical differences in brain-behavior relationships. Overall, our findings support a hybrid categorical–dimensional model for ASD.

Vitria Adisetiyo¹, Jens H. Jensen¹, Ali Tabesh¹, Rachael L. Deardorf¹, Kevin M. Gray², and Joseph A. Helpern^1,3
1Radiology and Radiological Science, Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, United States, ²Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States, ³Neuroscience, Medical University of South Carolina, Charleston, SC, United States

Dopamine (DA) deficiency is implicated in attention-deficit/hyperactivity disorder (ADHD) and is treated with psychostimulant medications that increase synaptic DA. Given that brain iron is required for DA metabolism and can be measured non-invasively with MRI, we examined brain iron as a potential indirect biomarker of DA status. Using magnetic field correlation imaging and R2*, we found comparable brain iron levels in controls and psychostimulant-medicated ADHD patients. Unlike controls, brain iron in patients did not increase with age but rather increased as a function of psychostimulant medication duration suggesting that longer psychostimulant treatment may normalize brain iron levels in ADHD patients.

Emma Muñoz-Moreno¹, Elda Fischi-Gomez^2,3, Dafnis Batalle⁴, Lana Vasung³, Morgane Reveillon³, Cristina Borradori-Tolsa³, Elisenda Eixarch^4,5, Jean-Philippe Thiran^2,6, Eduard Gratacos^4,5, and Petra Susan Hüppi^3
1Fetal and Perinatal Medicine Research Group, IDIBAPS, Barcelona, Barcelona, Spain, ²Ecole Polytecnique Fédérale de Laussane, Signal Processing Laboratory 5 (LTS5), Laussane, Switzerland, ³Division of Development and Growth, Department of Pediatrics, University of Geneva, Geneva, Switzerland,⁴Fetal and Perinatal Medicine Research Group, IDIBAPS, Barcelona, Spain, ⁵Maternal-Fetal Medicine Department, ICGON, Hospital Clinic, Universitat de Barcelona, Barcelona, Spain, ⁶Department of Radiology, University Hospital Center (CHUV) and University of Lausanne (UNIL), Laussane, Switzerland

Perinatal conditions, such as prematurity and intrauterine growth restriction (IUGR), altering normal brain development can have consequences in short- and long-term brain structure and function. Changes in brain connectivity associated to IUGR have been already described by connectomics. In this work, we use connectomics to analyse how brain network organization at 1-, 6- and 10-year-old children with and without IUGR correlates with their performance in neuropsychological tests. Results show a higher risk of social cognitive disorders, related to hyperactivity and altered executive function, in IUGR children, and a strong correlation between brain network metrics and neurodevelopmental evaluation.

Divya S Bolar^1,2, Borjan Gagoski³, Richard L Robertson⁴, Elfar Adalsteinsson⁵, Bruce R Rosen^1,2, and P Ellen Grant^3
1Department of Radiology, Massachusetts General Hospital, Boston, MA, United States, ²MGH/HST Martinos Center for Biomedical Imaging, Charlestown, MA, United States, ³Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, MA, United States, ⁴Department of Radiology, Boston Children's Hospital, MA, United States, ⁵Department of Electrical Engineering & Computer Science, Massachusetts Institute of Technology, MA, United States

Imaging cerebral blood flow (CBF) with traditional arterial spin labeling (ASL) is limited in diseases with delayed arterial transit such as ischemic stroke and moyamoya disease, resulting in large-vessel artifacts and perfusion underestimation. Velocity-selective ASL (VSASL) has been introduced to improve CBF quantification in these cases and is theoretically insensitive to arterial transit times. In this study, VSASL and traditional pulsed ASL were used to assess CBF in pediatric moyamoya patients. Results demonstrate that PASL is severely affected by delayed arterial transit, resulting in macrovascular artifact and perfusion defects, while VSASL appears unaffected, yielding expected microvascular perfusion. Angiographic data correlate these findings.