Allan R. Martin¹, Izabela Aleksanderek¹, Julien Cohen-Adad², Zenovia Tarmohamed³, Lindsay Tetreault¹, Nathaniel Smith⁴, David W. Cadotte¹, Adrian Crawley⁵, Howard Ginsberg¹, David J. Mikulis⁵, and Michael G. Fehlings^1
1Neurosurgery, University of Toronto, Toronto, ON, Canada, ²Electrical Engineering, Polytechnique Montreal, Montreal, QC, Canada, ³Royal College of Surgeons Ireland, Dublin, Ireland, ⁴McMaster University, Hamilton, ON, Canada, ⁵Medical Imaging, University of Toronto, Toronto, ON, Canada

5 state-of-the-art spinal cord MRI techniques have been identified with great clinical potential. This systematic review finds trends in the technical methods employed and measures the progress of these techniques toward clinical translation. 104 studies were identified, with 69 DTI, 25 MT, 1 MWF, 11 MRS, and 8 fMRI studies. The DTI metric FA has the strongest evidence of utility, correlating with disability in numerous spinal conditions. Large, well-designed studies with a priori hypotheses, standardized acquisition methods, detailed clinical data collection, and robust automated analysis techniques are needed to fully demonstrate the potential of these rapidly evolving techniques.

Manuel Taso^1,2,3,4, Pierre-Jean Arnoux^2,4, Léo Fradet^4,5, Arnaud Le Troter^1,3, Jean-Philippe Ranjeva^1,3,4, Kathia Chaumoître^4,6, Pierre-Hugues Roche^4,7, and Virginie Callot^1,3,4
1CRMBM UMR 7339, Aix-Marseille Université, CNRS, Marseille, France, ²LBA UMR T 24, Aix-Marseille Université, IFSTTAR, Marseille, France, ³CEMEREM, AP-HM, Pôle d'imagerie médicale, Marseille, France,⁴iLab-Spine international associate laboratory, Marseille/Montréal, France, ⁵Mechanical Engineering, Ecole Polytechnique de Montréal, Montréal, QC, Canada, ⁶Service de Radiologie, Hôpital Nord, AP-HM, Pôle d'imagerie médicale, Marseille, France, ⁷Service de Neurochirurgie, Hôpital Nord, AP-HM, Trauma Center, Marseille, France

While diagnosis of cervical spondylotic myelopathy is easily done with MRI, patient outcome is still difficult to predict. It is nonetheless associated to a strong mechanical cause as spinal cord’s (SC) compression is the first event leading to tissue alterations and neurological deficits. This work proposes an original approach using biomechanical numerical simulation, to apprehend the mechanisms of SC compression by the disk, and multi-parametric MRI, to probe the consequent microstructural alterations (axonal loss, demyelination …). Thanks to spatial normalization, first results on 3 patients are presented, allowing co-localization of personalized simulation of mechanical stress and structural MR alterations.

Samantha By^1,2, Alex K. Smith^1,2, Adrienne N. Dula^2,3, Bailey D. Lyttle², Siddharama Pawate⁴, and Seth A. Smith^2,3
1Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, ²Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ³Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, ⁴Neurology, Vanderbilt University, Nashville, TN, United States

Amide proton transfer (APT) CEST was applied to healthy and multiple sclerosis (MS) cohorts to determine its sensitivity to changes in normal appearing white matter in MS. Using a Lorentzian difference analysis, differences in the z-spectra of the MS and healthy cohorts around the APT frequency (Δω=+3.5 ppm) were observed. Significant differences in APT effect between MS and healthy controls were seen in the whole cord (p=0.0159), dorsal column (p=0.0159), and gray matter (p=0.0317). Lastly, a group-wise analysis highlights the ability to detect a decrease in mean APT effect in the MS cohort, despite the difficulty in detecting lesions in the anatomical.  

Hanwen Liu¹, Erin MacMillan ¹, Emil Ljungberg¹, Burkhard Mädler², Shannon Kolind ¹, Marcel Dvorak¹, David Li¹, Alex MacKay¹, John Kramer¹, Cornelia Laule¹, and Armin Curt^3
1University of British Columbia, Vancouver, BC, Canada, ²University of Bonn, Bonn, Germany, ³Balgrist University, Zürich, Switzerland

Cervical spondylotic myelopathy (CSM) is a major cause of spinal cord dysfunction. To better understand the pathophysiology underlying CSM, we used somatosensory evoked potentials (SSEPs) and myelin water imaging to study patients with CSM and healthy controls. Significant differences were found in the myelin water fraction (MWF) of the dorsal column between subjects classified as normal or pathological based on SSEPs. A strong correlation between tibial SSEP latency and MWF was found in CSM. Our findings suggest that MWF can monitor cervical spinal cord demyelination and may be a valuable tool to assess clinical interventions in spinal cord injury.

Ferran Prados^1,2, Marios C Yiannakas², Manuel Jorge Cardoso¹, Francesco Grussu², Floriana De Angelis², Domenico Plantone², David H Miller², Olga Ciccarelli², Claudia Angela Michela Gandini Wheeler-Kingshott^2,3, and Sebastien Ourselin^1
1Translational Imaging Group, Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, ²NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom, ³Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy

In this work, we introduce a new pipeline based on the latest iteration of the BSI for computing atrophy in the SC and compare its results with the most popular atrophy measurements for this region, mean CSA. We demonstrated for the first time the use of BSI in the SC, as a sensitive, quantitative and objective measure of longitudinal tissue volume change. The BSI pipeline presented in this work is repeatable, reproducible and standardises a pipeline for computing SC atrophy. 

Kwan-Jin Jung¹, Andrea Willhite², and Susan Harkema^2
1Radiology, University of Louisville, Louisville, KY, United States, ²Neurological Surgery, University of Louisville, Louisville, KY, United States

The cerebrospinal fluid (CSF) flow in the cervical spine was compared between healthy controls and persons with spinal cord injury (SCI) using phase contrast MRI.  The subarachnoid cross-section of SCI participants was smaller than that of healthy controls. The flow velocities in both diastolic and systolic cardiac phases were faster in SCI participants than that of healthy controls. Considering a slower heart rate and a reduced ejection fraction and stroke volume of the heart in SCI participants, the reduced subarachnoid area may be a main contributing factor to the increased velocity of CSF flow in SCI participants.

Mohamed Tachrount¹, Andrew Davies², Roshni Desai², Kenneth Smith², David Thomas¹, and Xavier Golay^1
1Dept. of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, United Kingdom, ²Dept. of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom

Perfusion-weighted imaging studies have demonstrated that there is a widespread cerebral hypoperfusion in patients with MS, regardless of the clinical subtype. The mechanism and the role of hypoxia are still unclear. The purpose of this work was to longitudinally investigate the SC blood flow (SCBF) during the different phases of disease progression in EAE rats using an optimized ASL technique. These measurements demonstrated for the first time on EAE animal model that the neurological deficits are strongly correlated with impaired blood flow.

Allan R. Martin¹, Benjamin De Leener², Izabela Aleksanderek¹, Julien Cohen-Adad², David W. Cadotte¹, Sukhvinder Kalsi-Ryan¹, Lindsay Tetreault¹, Adrian Crawley³, Howard Ginsberg¹, David J. Mikulis³, and Michael G. Fehlings^1
1Neurosurgery, University of Toronto, Toronto, ON, Canada, ²Electrical Engineering, Polytechnique Montreal, Montreal, QC, Canada, ³Medical Imaging, University of Toronto, Toronto, ON, Canada

This study investigates if DTI, MT, and T2*-weighted imaging of the rostral cervical cord can 1) detect injury of WM tracts, 2) correlate with global and focal disability, and 3) predict outcomes in degenerative cervical myelopathy (DCM). Data includes detailed clinical assessments, electrophysiology, and MRI, repeated at 1-year. Quantitative MRI in 37 DCM patients and 29 healthy controls provided reliable results and showed decreased CSA, FA, and MTR, and increased T2* WM/GM ratio. FA of individual tracts correlates well with clinical measures. Quantitative multimodal assessment of WM injury with a clinically feasible protocol is possible, with many potential clinical applications.

Yuhui Xiong¹, Xiaodong Ma¹, Xiaolong Chen², Li Guan², Yong Hai², Zhe Zhang¹, Le He¹, Chun Yuan^1,3, and Hua Guo^1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of, ²Department of Orthopedics, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China, People's Republic of, ³Vascular Imaging Laboratory, Department of Radiology, University of Washington, Seattle, WA, United States

As a conventional method in spinal cord assessment in cervical spondylotic myelopathy (CSM) patients, intramedullary high signal intensity (HSI) in T2W images is limited in diagnosis accuracy and predictive capacity for postoperative recovery. Single-shot EPI DTI can detect microstructural information, but it has low image resolution and distortion. In this work, a multi-shot interleaved EPI DTI using SYMPHONY reconstruction method is used to assess the pathologic conditions and the function of spinal cords of CSM patients quantitatively. The results show that the high resolution MS-EPI DTI can performs better than HSI or SS-EPI DTI in CSM diagnosis and recovery monitoring.

Jiachen Zhuo¹, Hegang Chen², Bizhan Aarabi³, Jay Menaker⁴, Rao Gullapalli¹, and Kathirkamanathan Shanmuganathan^1
1Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States, ²Epidemiology & Public Health, University of Maryland School of Medicine, Baltimore, MD, United States, ³Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, United States, ⁴Surgery, University of Maryland School of Medicine, Baltimore, MD, United States

Convention MRI is the imaging modality of choice to demonstrate the anatomical location and extent in spinal cord injury (SCI) following trauma. However, quantitative and qualitative lesion parameters within the cord are of limited use in predicting patient neurological outcomes. In this study we demonstrated that acute DTI measurements improve model prediction for 1 year AISA score following blunt cervical SCI. Among all DTI measurements, axial diffusivity, while not radial diffusivity, showed strong effect in predicting outcome, indicating that axonal injury in the cord may be the main factor affecting patient recovery.