Charley Gros¹, Abdullah Asiri^2,3, Benjamin De Leener⁴, Charles Watson⁵, Gary Cowin⁶, Marc Ruitenberg⁷, Nyoman Kurniawan², and Julien Cohen-Adad^1,8
1NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada, ²Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia, ³Radiology department, College of applied medical sciences, Najran University, Najran, Saudi Arabia, ⁴Department of Computer and Software Engineering, Polytechnique Montreal, Montreal, QC, Canada, ⁵Faculty of Health Sciences, Curtin University of Technology, Perth, Australia, ⁶National Imaging Facility, Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia, ⁷School of Biomedical Sciences, The University of Queensland, Brisbane, Australia, ⁸Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada

Spinal cord MRI templates allow reproducible and large scale atlas-based studies. However, current templates may have suboptimal resolutions (~0.5mm isotropic) to analyse high resolution data acquired at ultra-high field (e.g. 7T scanners). We generated a 3D human cervical cord template at 80µm isotropic resolution, from 13 ex vivo specimens, with a reference based on spinal levels. Further, the template was registered to the existing in vivo PAM50 template. Results showed consistency with histological studies in terms of grey matter morphology, and template generation achieved high accuracy (mean distance error: 0.10±0.01mm). The template and related scripts will be made publicly available.

Ole Geldschläger¹, Dario Bosch¹, Nikolai Avdievitch¹, Klaus Scheffler^1,2, and Anke Henning^1,3
1High-field Magnetic Resonance, Max-Planck-Institut for biolog. Cybernetics, Tübingen, Germany, ²Institute for Biomedical Magnetic Resonance, University Hospital Tübingen, Tübingen, Germany, ³Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States

This study presents the first investigations with algorithmic spinal cord-segmentation, as well as gray matter/white matter-segmentation within the spinal cord, at the ultrahigh field strength of 9.4T. On multi-echo gradient-echo acquisitions from three subjects, the tested algorithms perform the segmentations correctly. Based on these multi-echo data, pixel-wise T2*-relaxation time maps were calculated. By means of the segmentations, averaged T2*-times of 24.88ms +- 6.68ms for gray matter and 19.37ms +- 8.66ms for white matter, were calculated.

Ece Ercan¹, Thomas Ruytenberg¹, Kristin P. O’Grady^2,3, Seth A. Smith^2,3,4, Andrew Webb¹, and Irena Zivkovic^1
1C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands, ²Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, ³Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, ⁴Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States

Spinal cord imaging at 7T MRI is challenging and limited by the need for dedicated RF coils. In this study, we present a flexible coil design for cervical spinal cord imaging at 7T. B₁⁺ inhomogeneities were addressed by using multichannel array and phased-based RF shimming. Dorsal and ventral nerve roots, denticulate ligaments, and blood vessels were visible on axial T₂*-weighted images. Cross-sectional area measurements from C3-C4 cervical levels were consistent with literature values.
 

Benjamin De Leener^1,2, Linda Soltrand Dahlberg², Ali Khatibi^2,3, Julien Cohen-Adad^4,5, and Julien Doyon^2
1Department of computer engineering and software engineering, Polytechnique Montreal, Montreal, QC, Canada, ²Montreal Neurological Institute, McGill University, Montreal, QC, Canada, ³Center of Precision Rehabilitation for Spinal Pain (CPR Spine), University of Birmingham, Birmingham, United Kingdom, ⁴NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada, ⁵Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada

Acquiring high-quality functional MRI data of the spinal cord is challenging due to large susceptibility artifacts and high physiological noise, causing signal dropout and distorsions, particularly in the cervical region. This study demonstrated the beneficial effect of using non-protonated perfluorocarbon liquid-filled SatPads^TM during fMRI acquisition. Indeed, results show an increase of 31.51% for the global signal and 36.59% for the temporal signal-to-noise ratio for resting-state fMRI data acquired in the cervical spinal cord.

Arash Forodighasemabadi^1,2,3,4, Thomas Troalen⁵, Lucas Soustelle^1,2, Guillaume Duhamel^1,2, Olivier Girard^1,2, and Virginie Callot^1,2,4
1Aix-Marseille Univ, CNRS, CRMBM, Marseille, France, ²APHM, Hopital Universitaire Timone, CEMEREM, Marseille, France, ³Aix-Marseille Univ, IFSTTAR, LBA, Marseille, France, ⁴iLab-Spine International Research Laboratory, Marseille-Montréal, France, ⁵Siemens Healthcare SAS, Saint-Denis, France

Inhomogeneous Magnetization Transfer (ihMT) is a promising MRI technique, sensitive to myelinated tissue that can be used to study demyelinating pathologies such as MS. But the conventional MT and ihMT ratio metrics could be sensitive to T1 and B1 variations, especially in the context of spinal cord imaging. In order to minimize these effects, this study focuses on 3D ihMT-RAGE sequence with high FA reference acquisition and ihMTR inverse metric computation. The quantifications within GM and WM along the cervical spinal cord demonstrate that this technique is promising for investigating SC pathologies.

Feng Wang^1,2, Tung-Lin Wu¹, Pai-Feng Yang^1,2, Nellie E. Byun¹, Li Min Chen^1,2, and John C. Gore^1,2,3
1Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States, ²Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, ³Biomedical Engineering, Vanderbilt University, Nashville, TN, United States

Quantitative magnetization transfer (qMT) and diffusion tensor imaging (DTI) may detect and track compositional and structural changes in spinal cords before and after injury and during repair. This study aims to systematically evaluate the abilities of the qMT-derived pool size ratio (PSR) and DTI-derived diffusion parameters to assess injury-associated regional changes in spinal cords of monkeys, and to correlate them to specific sensorimotor behaviors. An overall goal is to evaluate the relationships between longitudinal changes in different regional MRI measures and sensorimotor behavioral impairment and recovery following spinal cord injury over a long period of time (months). 

Yuan Liu¹, Fengzhao Zhu², Xiangchuang Kong¹, Jiazheng Wang³, Xiaodong Guo², and Yang Lian^1
1Radiology, Union Hospital, Wuhan, China, ²orthopedics, Union Hospital, Wuhan, China, ³Philips Healthcare, Beijing, China

Baseline MRI was recommended in acute spinal cord injury for clinical decision making and outcome prediction. The study presented a new quantitative method for evaluating the spinal cord severity to grade the retained fiber tracks by zoom DTI in pre-operation. For patients with ASIA A, no ASIA grade got promoted in FTClass A1 with completely fibers interruption and 3 out of 6 patients converted to C within 6-month follow-up in FTclass A2 with partially retention. The retained spinal cord fibers were critical for postoperative functional recovery. Multimodal MRI, especially accurate DTI provide potential quantitative predictive indicators for prognosis.

Bhavana Shantilal Solanky¹, Ferran Prados¹, Carmen Tur¹, Selma Al-Ahmad², Xixi Yang¹, Baris Kanber³, David Choi², Jalesh N Panicker⁴, and Claudia A M Gandini Wheeler-Kingshott^1
1NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences, UCL, London, United Kingdom, ²National Hospital For Neurology and Neurosurgery, Queen Square, London, United Kingdom, ³Translational Imaging Group, Centre for Medical Image Computing, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, ⁴Department of Uro-neurology, National Hospital for Neurology and Neurosurgery, London, United Kingdom

Sodium retention as a consequence of spinal cord injury is thought to impair the regenerative ability of neurons but also reduce damage. Studies have shown that sodium-blockers can lead to improved outcomes in some SCI patients. Here alterations in spinal cord total sodium concentrations in spinal cord injury patients and healthy controls were investigated using sodium MRS. The association of sodium concentration to cross sectional area and ASIA score was also explored.

 

Sarah Rosemary Morris^1,2,3, Andrew Yung^1,3,4, Valentin Prevost^1,3,4, Shana I George⁵, Piotr Kozlowski^1,2,3,4, Andrew Bauman^1,3,4, Farah Samadi^1,6, Caron Fournier^1,6, Lisa Parker⁷, Kevin Dong¹, Femke Streijger¹, G.R. Wayne Moore^1,6,7,8, Brian Kwon^1,9,10, and Cornelia Laule^1,2,3,6
1International Collaboration on Repair Discoveries, Vancouver, BC, Canada, ²Physics & Astronomy, University of British Columbia, Vancouver, BC, Canada, ³Radiology, University of British Columbia, Vancouver, BC, Canada, ⁴UBC MRI Research Centre, Vancouver, BC, Canada, ⁵Carson Graham Secondary School, Vancouver, BC, Canada, ⁶Pathology & Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada, ⁷Vancouver General Hospital, Vancouver, BC, Canada, ⁸Medicine, University of British Columbia, Vancouver, BC, Canada, ⁹Vancouver Spine Surgery Institute, Vancouver, BC, Canada, ¹⁰Orthopaedics, University of British Columbia, Vancouver, BC, Canada

Spinal cord injuries are heterogeneous, with complex microstructure which changes over time. We used 7T Diffusion Tensor Imaging (DTI), Diffusion Basis Spectrum Imaging (DBSI) and inhomogeneous Magnetization Transfer (ihMT) to investigate microstructural damage in post-mortem human spinal cord injury tissue. We measured sharp decreases in DTI fractional anisotropy and DBSI fiber fraction at the injury epicentre of the three cords with the most severe injuries. We found evidence for downstream demyelination (ihMT) and axonal loss (DTI FA, DBSI fiber fraction) in the two cords with the longest injury-death interval suggesting a time-frame for the detection of Wallerian degeneration by MRI.  

Mark Andrew Hoggarth^1,2, James Elliott^2,3, Mary Kwasny⁴, Marie Wasielewski², Kenneth Weber⁵, and Todd Parrish^1,6
1Biomedical Engineering, Northwestern University, Chicago, IL, United States, ²Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, IL, United States, ³Northern Sydney Local Health District & Faculty of Health Sciences, The University of Sydney, Sydney, Australia, ⁴Preventive Medicine, Northwestern University, Chicago, IL, United States, ⁵Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Palo Alto, CA, United States, ⁶Radiology, Northwestern University, Chicago, IL, United States

Whiplash injuries are the most common outcome from non-fatal motor vehicle collisions, affecting nearly four million people in the United States each year. The purpose of this cross-sectional study was to investigate the macromolecular environment of cervical spinal cord white matter in participants with persistent whiplash. This investigation of 76 individuals demonstrated changes in cervical white matter integrity following whiplash injuries using magnetization transfer imaging. Significant differences in the magnetization transfer ratio homogeneity of large cervical white matter tracts were observed in females with poor clinical outcome, indicating a spinal cord insult may contribute to chronic pain after whiplash injury.

Kevin Vallotton¹, Maryam Seif¹, Markus Hupp¹, Armin Curt¹, and Patrick Freund^1,2,3
1Spinal Cord Injury Center, University Hospital Balgrist, University of Zurich, Zurich, Switzerland, ²Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, ³Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London, United Kingdom

Degenerative cervical myelopathy (DCM) is the most common form of non-traumatic spinal cord injury (SCI) and induces neurodegeneration in the cervical cord at and above the primary stenosis level. However, whether similar neurodegeneration occurs at the lumbar level remains unclear. We therefore applied high resolution T2*-weighted MRI in the lumbar cord in both DCM patients and healthy controls to investigate potential injury-induced structural changes. Significant atrophy was found in mild DCM patients and its magnitude was associated with sensory impairment.

Rebecca Sara Samson¹, Jonathan Stutters¹, Muhammad Ali Akbar², Armin Curt³, Julien Cohen-Adad^4,5, Michael Fehlings^2,6, Patrick Freund^3,7,8, Blair Innerarity¹, Maryam Seif³, Carmen Tur¹, and Claudia A. M. Gandini Wheeler-Kingshott^1,9,10
1NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, University College London, London, United Kingdom, ²Institute of Medical Science, University of Toronto, Toronto, ON, Canada, ³Spinal Cord Injury Center Balgrist, University of Zurich, Zurich, Switzerland, ⁴NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada, ⁵Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada, ⁶Krembil Research Institute, University Health Network, Toronto, ON, Canada, ⁷Department of Neurophysics, Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom, ⁸Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, ⁹Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy, ¹⁰Brain MRI 3T Center, IRCCS Mondino Foundation, Pavia, Italy

We explored diffusion tensor imaging (DTI) metrics along the corticospinal tract (CST) from the cervical cord to the motor cortex, measured using separate brain and cervical cord DTI protocols in healthy subjects and cervical spondylotic myelopathy (CSM) patients at two sites. Instead of looking at either brain or cord separately, here, we combine brain and cord measurements and examine how the CST is affected in CSM, in addition to exploring correlations with clinical measures. Statistically significant changes were observed between CSM and HC when comparing cord and brain CST data, demonstrating the sensitivity of CST metrics to cord pathology.

Simon Lévy^1,2,3,4, Pierre-Hugues Roche^4,5, and Virginie Callot^1,2,4
1Aix-Marseille Univ, CNRS, CRMBM, Marseille, France, ²APHM, Hopital Universitaire Timone, CEMEREM, Marseille, France, ³Aix-Marseille Univ, IFSTTAR, LBA, Marseille, France, ⁴iLab-Spine International Research Laboratory, Marseille-Montreal, QC, France, ⁵Neurosurgery Department, APHM, Hopital Nord, Marseille, France

The performance of Dynamic Susceptibility Contrast imaging at 7T for spinal cord perfusion mapping within clinical constraints was investigated. A cardiac-gated spin-echo EPI sequence with 0.7x0.7mm² in-plane resolution was used in one healthy volunteer and two Cervical Spondylotic Myelopathy patients. Relative blood volume and flow maps successfully revealed the higher perfusion of gray matter versus white matter for the volunteer and one patient. Results were limited for the patient with greater functional impairment and disadvantageous acquisition conditions. Although human spinal cord perfusion has never been mapped as precisely, several issues remain to address (image distortions, Specific-Absorption-Rate limitations, Arterial Input Function).
 

Marco Palombo¹, Francesco Grussu^1,2, Torben Schneider^1,2,3, Gabriele C. DeLuca⁴, Daniel C. Alexander¹, Claudia A. M. Gandini Wheeler-Kingshott^2,5,6, and Hui Zhang^1
1Centre for Medical Image Computing, Department of Computer Science, University College London, London, United Kingdom, ²NMR Research Unit, Queen Square MS Centre, Queen Square Institute of Neurology, Faculty of Brain Sciences, University College London, London, United Kingdom, ³Philips UK, Guildford, Surrey, United Kingdom, ⁴Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, ⁵Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy, ⁶Brain MRI 3T Center, IRCCS Mondino Foundation, Pavia, Italy

Multiple sclerosis (MS) is characterized by demyelination, extra-cellular matrix disruption, inflammation and astrocytic scarring of WM lesions. This study investigates the use of a recently introduced MRI technique called SANDI (Soma And Neurite Density Imaging) to provide histologically meaningful estimates of cell body (namely soma) density in MS spinal cord pathology. Our results on ex-vivo human spinal cord specimens show significant positive correlation between SANDI metrics (f_neurite and f_soma) and histological markers of myelination (plp) and astrocytes reactivity (gfap), respectively. The study suggests SANDI metrics as complementary imaging markers of demyelination (f_neurite), astrocytic scarring (f_soma) and extra-cellular matrix disruption (f_extra).

Anna Combes^1,2, Baxter P. Rogers^1,2, Mereze Visagie², Kristin P. O'Grady^1,2, Richard D. Lawless^2,3, Sanjana Satish², Atlee Witt², Shekinah Malone⁴, Colin D. McKnight², Francesca R. Bagnato⁵, John C. Gore^1,2,3, and Seth A. Smith^1,2,3
1Radiology & Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, ²Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, ³Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, ⁴School of Medicine, Meharry Medical College, Nashville, TN, United States, ⁵Clinical Neurology, Vanderbilt University Medical Center, Nashville, TN, United States

Functional connectivity (FC) in the cervical spinal cord can be assessed with 3T resting-state fMRI. FC strength in the ventral and dorsal networks was measured in a group of relapsing-remitting multiple sclerosis (MS) patients with low disability, high cervical lesion load, and mildly impaired sensorimotor function and was found similar to matched healthy controls. There was no impact of the presence of cord lesions, suggesting FC is preserved even in the presence of structural damage. Future work will explore the longitudinal trajectories of cord FC in support of intact or impaired sensorimotor function in MS.