Keith R Thulborn^1
1Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, IL, United States

The cell volume fraction (CVF), derived from tissue sodium concentration as measured by quantitative sodium MR imaging, in the human brain is high (~0.82) and maintained with normal aging despite decreases in brain volume. The gender difference (females: 0.807±0.009; males: 0.827±0.011, p<0.001) is also maintained over normal aging. This difference is posited to reflect the energy saving from higher CVF required for the larger male brain with higher number of neurons and synapses compared to female brains.

Xiaoxu Na¹, Rajikha Raja¹, Aline Andres^2,3, and Xiawei Ou^1,3,4
1Radiology, University of Arkansas for Medical Sciences, Little Rock, AR, United States, ²Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, United States, ³Arkansas Children’s Nutrition Center, Little Rock, AR, United States, ⁴Arkansas Children's Research Institute, Little Rock, AR, United States

This study examined relationships between mother’s physical activity during pregnancy and newborn’s brain cortical development. Healthy pregnant women were recruited and their physical activity level were monitored throughout pregnancy. Their newborns underwent a brain MRI examination at 2 weeks of postnatal age. Brain structural images were post-processed and mean cortical thickness for different brain regions was calculated. We found that at both 1st and 2nd trimester of pregnancy, there were significant positive correlations between mother’s physical activity level and newborn’s brain cortical thickness in multiple regions, suggesting positive impact of mother’s physical activity during pregnancy on offspring brain cortical development. 

ABDUR RAQUIB RIDWAN¹, Mohammad Rakeen Niaz¹, Yingjuan Wu¹, Shengwei Zhang², David A. Bennett², and Konstantinos Arfanakis^1,2
1Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States, ²Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, United States

Atlas based MRI investigations involving PD-weighted (PDw), T2-weighted (T2w) MRI sequences on older adults typically utilized younger adult templates such as those of the ICBM. Additionally, a thorough quantitative assessment of how available standardized PDw and T2w templates perform on aging population has not yet been performed. Here a new standardized high resolution PDw, T2w and T2 map templates of the MIITRA atlas dedicated for studies on older adults was developed using concepts of super-resolution and sparse-representation and compared to other available standardized templates in terms of image quality, inter-subject spatial normalization accuracy and representativeness of the older adult brain.

Sahar Ahmad¹, Fang Nan², Ye Wu¹, Zhengwang Wu¹, Weili Lin¹, Li Wang¹, Gang Li¹, Di Wu^3,4, and Pew-Thian Yap^1
1Department of Radiology and Biomedical Research Imaging Center (BRIC), The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, ²Department of Biostatistics, University of Washington, Seattle, WA, United States, ³Department of Biostatistics, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, ⁴Division of Oral and Craniofacial Health Research, Adams School of Dentistry, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States

Pooling and integrating diverse imaging data across multiple sites is key to big data analytics in neuroimaging. Data amassed from multiple studies are inevitably heterogeneous due to differences in scanners, acquisition protocols, and post-acquisition image processing pipelines, substantially complicating downstream analyses. Here, we present a harmonization technique for multi-site large-scale longitudinal and cross-sectional data. We demonstrate the utility of our method in removing non-biological variability in cortical thickness measurements of individuals from birth to 100 years of age. 

Alexander Saunders^1,2 and Stefan Blüml^1,2
1Radiology, Children's Hospital Los Angeles, University of Southern California, Los Angeles, CA, United States, ²Rudi Schulte Research Institute, Santa Barbara, CA, United States

We hypothesized in vivo MR spectra can be sufficiently described by spectra representing predominant cell/tissue types rather than individual metabolites. We sought to extract two putative basis spectra of grey matter and white matter from 584 single-voxel 3T MR spectra using the principal spectra analysis by linear modeling (PSALM) custom algorithm. Two extracted PSALM bases explained >95% of fit variance; principal component analysis required 6-8 components to achieve the same. We found the algorithm produced high signal-to-noise, low linewidth basis spectra that robustly fit in vivo spectra from normal brain.

Jian Shen¹ and John Wood^1,2
1University of Southern California, Los Angeles, CA, United States, ²Cardiology, Children's Hospital Los Angeles, Los Angeles, CA, United States

Asymmetric Spin Echo (ASE) is a popular technique to obtain quantitative estimates of R₂’, cerebral venous blood volume (vCBV), and oxygen extraction fraction (OEF) noninvasively in normal subjects. In this study, We demonstrated the feasibility of using Triple-Echo ASE to induce a more stable and accurate vCBV and OEF estimates with no increase in scan time. In addition, this study investigated the role of diffusion in ASE measurements and provided insights into future acquisition approaches.

Sahar Ahmad¹, Zhengwang Wu¹, Weili Lin¹, Gang Li¹, Li Wang¹, and Pew-Thian Yap^1
1Department of Radiology and Biomedical Research Imaging Center (BRIC), The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States

We show that spatial registration by simultaneously considering both tissue contrast and cortical geometry produces brain atlases that are more reflective of individuals than registration by considering only one of the two factors alone. Registration with tissue contrast alone produces atlases with blurred cortical structures. Registration with cortical geometry alone produces surface atlases that are artificially sharp but do not reflect surface attributes of individuals.

Maheen Zaidi^1,2,3, Jun Chen¹, Junjie Ma¹, Xiaodong Wen¹, Brenda Bartnik-Olson⁴, and Jae Mo Park^1,5,6
1Advanced Imaging Research Center, UT Southwestern, Dallas, TX, United States, ²Psychology, UT Dallas, Richardson, TX, United States, ³Neurobiology, UT Dallas, Richardson, TX, United States, ⁴Radiology, Loma Linda University, Loma Linda, CA, United States, ⁵Radiology, UT Southwestern, Dallas, TX, United States, ⁶Electrical Engineering, UT Dallas, Richardson, TX, United States

Maheen Zaidi^1,2,3, Binu P. Thomas^1,4, Junjie Ma¹, Salvador Pena¹, Jun Chen¹, James Ratnaker¹, Craig R. Malloy^1,4,5, Brenda Bartnik-Olson⁶, and Jae Mo Park^1,4,7
1Advanced Imaging Research Center, UT Southwestern, Dallas, TX, United States, ²Psychology, UT Dallas, Richardson, TX, United States, ³Neurobiology, UT Dallas, Richardson, TX, United States, ⁴Radiology, UT Southwestern, Dallas, TX, United States, ⁵Internal Medicine, UT Southwestern, Dallas, TX, United States, ⁶Radiology, Loma Linda University, Loma Linda, CA, United States, ⁷Electrical and Computer Engineering, UT Dallas, Richardson, TX, United States

[¹³C]Bicarbonate production from hyperpolarized [1-¹³C]pyruvate in the brain is directly related to pyruvate oxidation and, thus serves a potential biomarker of brain function. In this study, we assessed time-wise bicarbonate production in the visual cortex during activation with minimal perturbation of its precursors, pyruvate and lactate, using a multichannel ¹³C receive array, a spectral-spatial RF pulse that fully excites bicarbonate signals, and dynamic ¹³C MRS. The real-time changes of bicarbonate production in response to visual stimuli were observed in healthy volunteers.

Xiao-Hong Zhu¹, Hannes M Wiesner¹, Yudu Li^2,3, Wei Zhu¹, Tao Wang¹, Xin Li¹, Zhi-Pei Liang^2,3, and Wei Chen^1
1University of Minnesota, Minneapolis, MN, United States, ²Beckman Institute for Advanced Science and Technology, Urbana, IL, United States, ³Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States

The emerging deuterium MRS (DMRS) imaging (DMRSI) technology has shown great promise in studying brain glucose metabolism, TCA cycle and glycolytic activity. In particular, its potential as a clinical tool for tumor detection in brain or other organs has attracted a lot of attention. However, the temporal and spatial resolution of dynamic DMRSI is limited by its low detection sensitivity. In this study, we proved that 7T high-resolution dynamic DMRSI combined with SPICE method can not only map the Glx production rate constant, but also distinguish the TCA cycle activity level between human brain gray matter and white matter.

Gabriel Ramos-Llorden¹, Berkin Bilgic^1,2, and Susie Y. Huang^1,2
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States, ²Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, United States

In this work, we accelerate the high-SNR, high-spatial resolution in vivo diffusion MRI technique gSlider by applying subsampling jointly in the k,-q, and RF-encoding space. Good reconstruction quality is achieved if complementary information from the multi-dimensional space k-,q-, and RF-space is combined in a complementary fashion and the reconstruction problem is solved jointly.

Riwei Jin¹, Brad Sutton¹, Ryan Keith Shosted¹, Jonghye Woo², Fangxu Xing², Jamie Perry³, Imani Gilbert³, and Zhipei Liang^1
1University of Illinois Urbana-Champaign, Champaign, IL, United States, ²Massachusetts General Hospital, Boston, MA, United States, ³East Carolina University, Greenville, NC, United States

We are able to push the spatial resolution of dynamic speech magnetic resonance imaging to 2-mm near-isotropic level with 64 mm coverage of 32 3D slice locations that are spaced 2-mm apart with 35 fps. We choose to analyze lingual differences of American English voiced lateral [l] and (central) [t]. Several analysing methods are utilized such as magnitude comparison, t-test and deformation map comparison.  The results give us detailed observations of lingual articulatory differences such as tongue grooving, twisting and coarticulation. Through this high spatial and temporal resolution, we demonstrate that this method will show great potentials on linguistic research.

Jack A Reeves¹, Niels Bergsland^1,2, Dejan Jakimovski¹, Fahad Salman¹, Juliane Damm¹, Nicklas Meineke¹, Michael G Dwyer^1,3, Robert Zivadinov^1,3, and Ferdinand Schweser^1,3
1Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States, ²MR Research Laboratory, IRCCS, Don Gnocchi Foundation ONLUS, Milan, Italy, ³Center for Biomedical Imaging, Clinical and Translational Science Institute, University at Buffalo, The State University of New York, Buffalo, NY, United States

Magnetic resonance imaging (MRI) studies have shown age and neurological disease affect iron concentrations in the deep gray matter (DGM). However, it is unknown whether iron accumulation occurs independently across DGM regions or in inter-regional patterns, i.e. “iron networks”. Here, we identified two highly reproducible, inter-regional DGM iron networks by applying independent component analysis (ICA) to quantitative susceptibility maps (QSM) from healthy volunteers. Areas of network overlap had relatively high iron concentrations and each network was related to separate environmental variables, indicating they have independent mechanisms of iron change. Our results advance the understanding of brain iron physiology.

L. Tugan Muftuler¹, Timothy B. Meier ¹, and Michael A. McCrea^1
1Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States

Despite high prevalence of concussion in contact sports, there is still a lack of reliable, unbiased biomarkers of brain injury and recovery following sport-related concussion. The changes in imaging biomarkers after concussion are generally subtle such that signs of abnormalities are detected only in group analyses with large cohorts. Although diffusion MRI techniques show promise, detecting injury in individual subjects is still a challenge. The goal of this project is to identify potential signatures of brain injury in an individual subject with concussion using an unsupervised learning method using parameters derived from diffusion kurtosis imaging (DKI).

Lei Zhang¹, Ryan McNaughton², Hernan Jara², David N. Kennedy³, Carmen A. Marable¹, Ning Hua⁴, Karl C. K. Kuban⁴, T. Michael O'Shea¹, and Rebecca C. Fry^1
1University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, ²Boston University, Boston, MA, United States, ³University of Massachusetts Chan Medical School, Worcester, MA, United States, ⁴Boston University Medical Center, Boston, MA, United States