Samira Mchinda^1,2,3, Rémi Dintrich^1,2, Arnaud Le Troter^1,2, Pini Lauriane^1,2, Shahram Attarian⁴, Annie Vershueren⁴, and Virginie Callot^1,2,3
1Aix-Marseille Univ, CNRS, CRMBM, Marseille, France, Marseille, France, ²APHM, Hopital Universitaire Timone, CEMEREM, Marseille, France, Marseille, France, ³iLab-Spine International Associated Laboratory, Marseille-Montreal, France-Canada, Marseille, France, ⁴APHM, Hôpital Universitaire Timone, Reference Center for Neuromuscular Disorders and ALS, Marseille, France, Marseille, France

With comparable acquisition times between 3T and 7T, 7T quantitative protocol offers better resolution and many opportunities to study regional impairments, especially in anterior gray matter subregions.

This preliminary study focused on ALS and age-matched healthy controls scanned at both 3T and 7T. 

With the current postprocessing, abnormalities were mostly detected on the lower part of the cord (GM atrophy, WM/GM T1 impairments).

Future work will focus on longitudinal evolution and refined analysis to evaluate the sensitivity for prognostication and to determine individual topological evolution.

Chaoqi Mu¹, Jamie L Reed¹, Mohammed Noor Tantawy¹, Feng Wang¹, Li Min Chen¹, and John C Gore^1
1Vanderbilt University Institute of Imaging Science & Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States

Spinal cord injury (SCI) severity/recovery are influenced by complex pathological mechanisms. We used CEST/NOE MR and TSPO PET imaging to evaluate longitudinal molecular changes associated with neuroinflammation in a lumbar contusion SCI rodent model. The NOE(-1.6 ppm) peak amplitude significantly decreased and the CEST(3.5 ppm) peak amplitude increased in SCI rats, 1-week post-injury. Similarly, we detected significant increase in the uptake of a TSPO-targeting PET radiotracer at the SCI epicenter. The CEST/NOE pools can be linked to neuroinflammatory activity associated with glutamate release. The results indicate that CEST/NOE MRI measurements provide complementary information to TSPO PET measurement in SCI.

Simon Schading¹, Gergely David¹, Tim Max Emmenegger¹, Cristian Achim¹, Armin Curt¹, and Patrick Freund^1,2,3
1Spinal Cord Injury Center, Balgrist University Hospital, Zürich, Switzerland, ²Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London, United Kingdom, ³Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany

We tracked remote neurodegenerative changes in the cervical cord following spinal cord injury over 2 years using macrostructural readouts (cross-sectional area, left-right width, anterior-posterior width) derived from T1-weighted MPRAGE images. Thereby, we evaluated the dependency of the magnitude of atrophy on the distance to the lesion. Over time, differences in atrophy rates along the cervical cord rostral to the lesion gradually formed a lesion gradient. Using anterior-posterior width and left-right width as surrogates for investigating anterograde and retrograde degeneration separately, our results suggest that these two types exhibit different spatiotemporal dynamics. A lesion gradient was only observable for retrograde degeneration.

Sarah Rosemary Morris^1,2,3, Taylor Swift-LaPointe², Andrew Yung^1,3,4, Valentin Prevost^1,3,4, Shana George¹, Andrew Bauman⁴, Piotr Kozlowski^1,2,3,4, Farah Samadi^1,5, Caron Fournier^1,5, Lisa Parker⁶, Kevin Dong¹, Femke Streijger¹, Veronica Hirsch-Reinshagen^1,5,6, G.R. Wayne Wayne Moore^1,5,6, Brian K Kwon^1,7, and Cornelia Laule^1,2,3,5
1International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada, ²Physics & Astronomy, University of British Columbia, Vancouver, BC, Canada, ³Radiology, University of British Columbia, Vancouver, BC, Canada, ⁴Faculty of Medicine, UBC MRI Research Centre, Vancouver, BC, Canada, ⁵Pathology & Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada, ⁶Vancouver General Hospital, Vancouver, BC, Canada, ⁷Orthopaedics, University of British Columbia, Vancouver, BC, Canada

We investigated the relationship between diffusion model biomarkers and inflammatory cells, as measured by HLA-DR and CD68 histological staining for activated microglia and macrophages, after human traumatic spinal cord injury. Fractional anisotropy decreases and radial and mean diffusivity increases were strongly correlated with the presence of activated microglia and macrophages. ActiveAx-derived intra-cellular volume fraction and axon density decreased while axon diameter increased. Fiber fraction from Diffusion Basis Spectrum Imaging decreased and while hindered fraction increased in the presence of inflammation.

Whitney Freeze¹, Maria Clara Zanon Zotin^2,3, Ashley Scherlek², Valentina Perosa², Andrew Warren², Louise van der Weerd¹, Dorothee Schoemaker Marcotte², Mitchell Horn², Edip Gurol², Elif Gokcal², Brian Bacskai², Anand Viswanathan², Steven Greenberg², Yael Reijmer⁴, and Susanne van Veluw^1,2
1Leiden University Medical Center, Leiden, Netherlands, ²Massachusetts General Hospital, Boston, MA, United States, ³Ribeirão Preto medical School, São Paulo, Brazil, ⁴University Medical Center Utrecht, Utrecht, Netherlands

We assessed the contribution of small vessel disease lesions in the corpus callosum (CC) to vascular cognitive impairment in cerebral amyloid angiopathy (CAA). A total number of 21 CC lesions was found in 19/65 (29%) CAA patients. CC lesion presence was associated with reduced microstructural white matter integrity within the CC and in the whole brain white matter. Patients with CC lesions performed significantly worse on multiple cognitive domains compared to those without CC lesions after correcting for relevant covariates. Together, our findings suggest that CC lesions independently contribute to cognitive impairment through strategic microstructural disruption of white matter tracts. 

Ting Gong¹, Francesco Grussu^2,3, Claudia AM Gandini Wheeler-Kingshott^4,5,6, Daniel C Alexander¹, and Hui Zhang^1
1Centre for Medical Image Computing, Department of Computer Science, University College London, London, United Kingdom, ²Radiomics Group, Vall d’Hebron Institute of Oncology, Vall d’Hebron Barcelona Hospital Campus, Barcelona, Spain, ³Queen Square MS Centre, Queen Square Institute of Neurology, Faculty of Brain Sciences, University College London, London, United Kingdom, ⁴NMR Research Unit, Queen Square Multiple Sclerosis Centre, Department of Neuroinflammation, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom, ⁵Brain Connectivity Centre, IRCCS Mondino Foundation, Pavia, Italy, ⁶Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy

The very low SNR in spinal cord diffusion MRI can make robust microstructure parameter estimation challenging. To address unreliable parameter estimations under such low SNR, we propose a deep-learning-informed maximum likelihood estimation (MLE) approach, where a deep-learning model is trained to initialise MLE efficiently and optimally. In testing NODDI-derived parameters, simulation and in vivo experiments suggest the DL-informed method can reduce outlier estimates from conventional grid-search MLE, and at the same time, avoid biases from pure DL estimation under the low SNR. The proposed method also speeds up the computation, making it a promising tool for future applications.

Qinyang Shou¹, Xingfeng Shao¹, and Danny JJ Wang^1
1Laboratory of Functional MRI Technology (LOFT), Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, United States

The purpose of this study was to measure the spinal cord blood flow using high-resolution multi-delay pCASL. An optimized background suppression scheme was applied to suppress the cerebrospinal fluid signal. In-vivo study was performed on 5 healthy subjects. The results show stable cervical spinal cord (C1-C3) blood flow values within the spinal cord ROI, supporting the potential for further development and evaluation studies on noninvasive MRI of spinal cord perfusion.

D Rangaprakash¹ and Robert L Barry^1,2
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, ²Harvard-Massachusetts Institute of Technology Division of Health Sciences & Technology, Cambridge, MA, United States

Spinal cord fMRI data analysis involves niche pre- and post-processing steps due to the cord’s unique anatomy and higher distortions/physiological noise in fMRI data, requiring extensive and careful quality control (QC). However, there is paucity of open-source tools tailored to this need. Building upon 10 years of research and development, we present Neptune, a user-interface-based MATLAB toolbox. It can perform an array of tailored pre- and post-processing steps, including functional connectivity and statistics. It generates extensive QC plots and presents them to view in an elegant webpage format. We demonstrate the utility of Neptune on a 7T dataset.