Hui Huang¹, Jia Wang¹, Miao Zhang², Wei Liu³, Lihong Tang¹, Yibo Zhao^4,5, Rong Guo^4,5, Yudu Li^4,5, Zhi-Pei Liang^4,5, Yao Li¹, Biao Li², and Jie Luo^1
1School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China, ²Department of Nuclear Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China, ³Department of Neurosurgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China, ⁴Department of Electrical and Computer Engineering, University of Illinois at Urbana Champaign, Urbana, IL, United States, ⁵Beckman Institute for Advanced Sciences and Technology, University of Illinois at Urbana Champaign, Urbana, IL, United States

Both PET and MRSI could provide metabolic information of the epileptogenic zone, which could add value to presurgical planning of epilepsy patients. This study investigated metabolic alternations in patients with temporal lobe epilepsy (TLE) across their brain regions with different epileptogenicity, as defined using stereo-EEG (SEEG). Our experimental results showed FDG hypometabolism and NAA decrease in epileptogenic zone and propagation zone. These findings may lay a foundation for further investigation of tissue damage associated with epileptogenicity using high-resolution metabolic imaging.

Augusto Lio M. Goncalves Filho^1,2, Chanon Ngamsombat³, Stephen F. Cauley², Wei Liu⁴, Daniel N. Splitthoff⁵, Wei-Ching Lo⁶, John E. Kirsch¹, Pamela W. Schaefer¹, Otto Rapalino¹, Susie Y. Huang^1,2, and John Conklin^1,2
1Department of Radiology, Massachusetts General Hospital, Boston, MA, United States, ²Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, ³Department of Radiology, Siriraj Hospital, Bangkok, Thailand, ⁴Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, China, ⁵Siemens Healthcare GmbH, Erlangen, Germany, ⁶Siemens Medical Solutions Inc., Boston, MA, United States

We performed a systematic comparison of highly accelerated Wave-CAIPI 3D SPACE FLAIR versus standard 3D SPACE FLAIR for the imaging evaluation of 77 patients with seizures or established epilepsy undergoing 3T MRI. There were no significant differences between the two sequences for the detection of lesions and overall diagnostic quality, despite a 2.5- to 4-fold decrease in acquisition time using Wave-CAIPI SPACE FLAIR. The application of highly accelerated 3D imaging using Wave-CAIPI technology may improve use of MRI resources while reducing motion artifacts and patient anxiety.

Yao-Chia Shih^1,2,3, Fa-Hsuan Lin^4,5, Aeden Kuek Zi Cheng¹, Horng-Huei Liou^6,7, and Wen-Yih Isaac Tseng^3,7,8,9
1Department of Diagnostic Radiology, Singapore General Hospital, Singapore, Singapore, ²Duke-NUS Medical School, Singapore, Singapore, ³Institute of Medical Device and Imaging, College of Medicine, National Taiwan University, Taipei, Taiwan, ⁴Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, ⁵Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada, ⁶Department of Neurology, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan, ⁷Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, Taiwan, ⁸Department of Medical Imaging, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan, ⁹Molecular Imaging Center, National Taiwan University, Taipei, Taiwan

To seek neural correlates of seizure recurrence, the structural equation modeling (SEM) and resting-state functional MRI were performed to evaluate intrinsic effective connectivity (iEC) within the Papez circuit, hippocampal–diencephalic–cingulate (HDC) model, and simplified HDC model in patients with left and right temporal lobe epilepsy. We verified that the simplified HDC model was the best model to estimate iEC and found associations between seizure frequency and aberrant iEC on the paths connecting to the mammillary body. Our findings could facilitate the discovery of potential epilepsy pathways and the development of novel targeted therapies for unilateral temporal lobe epilepsy.

Yi-Tien Li^1,2, Duen-Pang Kuo^2,3, Yun-Ting Lee², Yung-Chieh Chen^2,3, Hsiao-Wen Chung⁴, and Cheng-Yu Chen^2,3,5,6
1Neuroscience Research Center, Taipei Medical University, Taipei, Taiwan, ²Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan, ³Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan, ⁴Graduate Institute of Biomedical Electrics and Bioinformatics, Taipei, Taiwan, ⁵Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, ⁶Research Center for Artificial Intelligence in Medicine, Taipei Medical University, Taipei, Taiwan

This study is the first to provide strong evidence that thalamocortical dysrhythmia (TCD) is involved in mild traumatic brain injury (mTBI) and plays a crucial role in protracted symptoms. The  impaired cortical–thalamic tracts and thalamic reticular nuclei are recognized as two pathomechanisms of TCD in mTBI. TCD-induced thalamocortical disinhibition, such as within-thalamus hyperconnectivity, widespread low-frequency thalamocortical coherence, and thalamo-default-mode network disinhibition, are associated with patients’ prolonged symptoms, which were consistently presented at 1- and 2-year follow-ups. Our systematic analysis strengthens understanding of TCD involvement in mTBI and provides future directions for diagnosis, prognosis, and treatment of long-lasting symptoms in mTBI.

Xiaowei Zhuang^1,2, Lauren Bennett³, Virendra Mishra¹, Zhengshi Yang^1,2, Karthik Sreenivasan^1,2, Aaron Ritter¹, Charles Bernick^1,4, and Dietmar Cordes^1,2,5
1Lou Ruvo Center For Brain Health, Cleveland Clinic, Las Vegas, NV, United States, ²University of Nevada, Las Vegas, Las Vegas, NV, United States, ³Hoag Memorial Hospital Presbyterian, Newport Beach, CA, United States, ⁴UW Medicine, Seattle, WA, United States, ⁵University of Colorado Boulder, Boulder, CO, United States

Longitudinal changes in fighters’ cognitive performance and brain structural (cortical thickness) and functional (seeded functional connectivity) measures following their transitions to inactive fighting status were investigated and compared with fighters who remain active. A linear mixed effect model was applied for each measure. When fighters transitioned to inactive status, improvements in cognitive performances, structural thickness measures and related functional connectivity measures are evident. In contrast, in fighters who continue to compete in professional matches, neuropsychological performances and structural and functional brain measures are observed to remain largely stable or reflect subtle declines across time points.

Ziying Yin¹, Matthew C. Murphy¹, Yi Sui¹, Armando Manduca², Richard L. Ehman¹, and John III Huston^1
1Radiology, Mayo Clinic, Rochester, MN, United States, ²Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, United States

There is growing recognition of morbidity resulting from subconcussive repetitive head impact (RHI).  Mechanical interactions between the skull-brain interface (e.g., transmission and tethering) contribute significantly to the response of the brain to head impact. Local cortical strain concentrations would likely reflect the nearby tethering interactions at the skull-brain interface. In this study, we have developed  MR elastography (MRE)-based methods that enable in vivo visualization and quantification of 3D full-volume cortical strain in response to non-impact dynamic loading. We have found that the distribution of the cortical strain is region-dependent, constituting a possible mechanism for RHI vulnerability among individuals.

Caroline Guglielmetti^1,2, Kai Qiao^1,2, Brice Tiret^1,2, Karen Krukowski^1,3, Amber Nolan^3,4, Susanna Rosi^1,3,5,6, and Myriam M. Chaumeil^1,2
1Department of Physical Therapy and Rehabilitation Science, University of California San Francisco, San Francisco, CA, United States, ²Department of Radiology and Biomedical Sciences, University of California San Francisco, San Francisco, CA, United States, ³Brain and Spinal Injury Center, University of California San Francisco, San Francisco, CA, United States, ⁴Department of Pathology, University of California San Francisco, San Francisco, CA, United States, ⁵Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, United States, ⁶Weill institute for Neuroscience, University of California San Francisco, San Francisco, CA, United States

We used hyperpolarized ¹³C magnetic resonance spectroscopic imaging (HP ¹³C MRSI), T1- and T2-MRI to detect brain alterations in a mouse model of mild repetitive traumatic brain injury (rTBI). T1/T2-MRI did not detect brain damages. HP ¹³C MRSI detected metabolic changes in cortical areas, with decreased HP lactate/pyruvate and pyruvate dehydrogenase activity in rTBI. Interestingly, HP pyruvate and HP urea increased in rTBI, suggesting vascular and/or blood brain barrier alterations. Altogether, we demonstrated that HP ¹³C MRSI has potential to detect long-lasting metabolic alterations following rTBI and holds great potential for improving diagnosis and monitoring of rTBI in clinical practice.

Nicolò Rolandi¹, Fulvia Palesi^1,2, Francesco Padelli³, Isabella Giachetti³, Domenico Acquino³, Paul Summers⁴, Giancarlo Germani⁴, Gerardo Salvato^1,5,6, Valeria Mariani⁵, Pina Scarpa^5,6, Egidio D'Angelo^1,2, Gabriella Bottini^1,5,6, Laura Tassi⁵, Paolo Vitali^4,7, and Claudia Angela Michela Gandini Wheeler-Kingshott^1,2,8
1Department of Brain and Behavioral Science, University of Pavia, Pavia, Italy, ²Brain Connectivity Center Research Deparment, IRCCS Mondino Foundation, Pavia, Italy, ³I.R.C.C.S. Istituto Neurologico Carlo Besta, Milano, Italy, ⁴Neuroradiology Unit, IRCCS Mondino Foundation, Pavia, Italy, ⁵Hospital Niguarda, Milano, Italy, ⁶Milan Center for Neuroscience, Milano, Italy, ⁷Department of Radiology, IRCCS Policlinico San Donato, Milano, Italy, ⁸NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Queen Square Institute of Neurology, Faculty of brain Sciences, University College London (UCL), London, United Kingdom

Advance tractography were performed on cerebro-cerebellar and long association fibers, characterized with diffusion tensor imaging, diffusion kurtosis imaging and NODDI parameter maps. The aim of this work is investigate whether white matter alterations of specific tracts can be selectively related to disfunction of declarative long term memory. Our findings show how  relationship between microstructural alterations and neuropsychological scores should be investigated taking account in specific area of white matter restriced to tracts or bundle. 

TERESA GERHALTER¹, Martijn Cloos², Seena Dehkharghani¹, Anna M. Chen¹, Rosermary Peralta¹, Fatemeh Adlparvar¹, James S. Babb¹, Tamara Bushnik³, Jonathan M. Silver⁴, Brian S. Im³, Stephen P. Wall⁵, Guillaume Madelin¹, and Ivan Kirov^1
1Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, NEW YORK, NY, United States, ²Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia, ³Department of Rehabilitation Medicine, New York University Grossman School of Medicine, NEW YORK, NY, United States, ⁴Department of Psychiatry, New York University Grossman School of Medicine, NEW YORK, NY, United States, ⁵Ronald O. Perelman Department of Emergency Medicine, New York University Grossman School of Medicine, NEW YORK, NY, United States

We analyzed brain MRI data including clinical imaging and MR fingerprinting (MRF) of 22 mild traumatic brain injury (mTBI) patients measured ~1 month after injury and 18 healthy controls. T1 and T2 values in mTBI were not significantly different from controls’. However, increased T1 of three brain regions enabled the identification of non-recovered patients at 3-months (AUC=0.80-0.88). This suggests that T1 quantification is more sensitive to mTBI damage than T2, and is a potential candidate to predict patient outcome.

Allen A Champagne¹, Nicole S Coverdale², Andrew Ross³, Christopher I Murray³, Isabelle Vallee⁴, and Douglas J Cook^5
1School of Medicine, Queen's University, Kingston, ON, Canada, ²Center for Neuroscience Studies, Queen's University, Kingston, ON, Canada, ³Performance Phenomics, Toronto, ON, Canada, ⁴National Defence Headquarters, Ottawa, ON, Canada, ⁵Department of Surgery, Queen’s University, Kingston, ON, Canada

Chronic exposure to head trauma in Special Forces personnel may provide a mechanism for changes in connectivity making-up the architectural organization of functional hubs. Here, resting-state MRI and diffusion tensor imaging are integrated to highlight interdependent differences in functional and structural connectivity of Canadian military Special Operations Forces personnel, when compared to civilian. Changes in white matter integrity of fibers directly connecting functional nodes were observed, which may explain, at least in part, changes in functional markers within networks.  These findings suggest a potential structural compensatory relationship between axonal injury and neural recruitment following head trauma from high-exposure military duties.