Room 255 EF

16:00 - 18:00

Moderators:

Guillaume Duhamel, Meng Law

Ashley D. Harris¹, Ann M. Taylor², Judith E. Hall², and Richard G. Wise^1
1CUBRIC, School of Psychology, Cardiff University, Cardiff, United Kingdom, ²Department of Anaesthetics, Cardiff University, Cardiff, United Kingdom

Cerebral blood flow differences between chronic pain patients compared to healthy control was quantified. Regions that displayed significant difference in CBF and that have been previously shown to have difference in functional connectivity were then used as seed regions to examine alterations in connectivity between patients and controls.

Virginie Callot¹, Léo Fradet^2,3, Jean-Philippe Ranjeva⁴, Guillaume Duhamel¹, Olivier M. Girard⁴, Pierre-Jean Arnoux², and Yvan Petit^3
1Centre de Résonance Magnétique Biologique et Médicale (CRMBM, UMR 7339), Aix-Marseille University, Marseille, France, ²Laboratoire de Biomécanique Appliquée (LBA, UMRT 24), IFSTTAR / Aix-Marseille Université, Marseille, France, ³Department of Mechanical Engineering, École de technologie superieure, Montreal, Quebec, Canada, ⁴Centre de Résonance Magnétique Biologique et Médicale (CRMBM, UMR 7339), CNRS / Aix-Marseille Université, Marseille, France

The objective of this study was to investigate SC morphological statistical differences (intra/inter-individual, age, sex, postmortem/in vivo) and to provide “invariant” features of the complete in vivo human normal spinal cord that may serve as database for individualized study of SC pathophysiological conditions, either for clinical practice and prognosis evaluation or to establish an accurate model of the SC that will open new perspectives to study compressive mechanisms such as encountered in SC injury or spondylotic myelopathy.

I-Wen Evan Chen¹, Jie Liu², Wolfram Tetzlaff^2,3, Vanessa Wiggermann⁴, Edenino Hernandez-Torres⁴, Piotr Kozlowski^4,5, and Alexander Rauscher^4,5
1MRI Research Center, Vancouver, B.C., Canada, ²International Collaboration On Repair Discoveries, Vancouver, B.C., Canada, ³Zoology, University of British Columbia, Vancouver, B.C., Canada, ⁴UBC MRI Research Centre, Vancouver, B.C., Canada, ⁵Radiology, University of British Columbia, Vancouver, B.C., Canada

Tissue microstructure is regarded as a major source of white and gray matter contrast in phase images produced with gradient echo (GE) imaging in the CNS. We investigated frequency shift in excised rat spinal cords with dorsal column transection injury scanned at 7T parallel to main magnetic field B₀. Comparing them to corresponding Eriochrome Cyanide (myelin) stained tissue sections, we found strong correlation between myelin and frequency shift both 5mm distal and proximal to injury. These preliminary results suggest GE phase imaging of injured rat spinal cords provides a good model for assessing tissue microstructure contributions to MR frequency shifts.

Linqing Li¹, Yazhuo Kong¹, Yuri Zaitsu¹, Lucy A.E. Matthews², and Peter Jezzard^1
1FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, ²Oxford University Hospitals NHS Trust, University of Oxford, Oxford, United Kingdom

DANTE pulse trains are rapid series of low flip angle pulses interspersed with gradients. It’s been previously demonstrated during application of DANTE, flowing CSF is largely attenuated relative to static tissue signal is mostly preserved. In this study, multi-contrast CSF-suppressed sequence using DANTE prepared 2D-TSE was implemented and compared to non-prepared 2D-TSE and MEDIC sequences. Preliminary results demonstrate metrics of contrast-to-noise ratio between spinal cord and CSF regions (CNRcord) in DANTE-TSE images is improved by a factor of 2 compared with images acquired with conventional approaches. Sagittal Imaging quality can be significantly improved due to flow-suppression effects from DANTE pluses.

Olivier M. Girard¹, Virginie Callot², Benjamin Robert³, Patrick J. Cozzone⁴, and Guillaume Duhamel^2
1CRMBM UMR 7339, CNRS / Aix-Marseille Université, Marseille, France, ²CRMBM UMR 7339, Aix-Marseille University, Marseille, France, ³Siemens Healthcare, Saint-Denis, France, ⁴CRMBM UMR 7339, Aix-Marseille Université, Marseille, France

Spinal cord (SC) perfusion is involved in post-traumatic recovery processes and is responsible for secondary injuries, hence it is a critical function to assess and monitor in order to establish correct diagnosis and prognosis of SC injured patients. Preliminary results have been obtained recently, demonstrating the feasibility of Arterial Spin Labeling perfusion imaging on human SC. This report summarizes recent advances in this field. Although the presented methods require more reliability, this work should pave the way to future developments leading to robust SC perfusion measurements, hence providing a valuable clinical tool for SC disease characterization.

Novena Rangwala¹, Gopal Varma¹, David Hackney¹, and David C. Alsop^1
1Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States

Previous studies proposed a new magnetization transfer (MT)-based contrast mechanism referred to as inhomogeneous magnetization transfer (ihMT) and showed its sensitivity and specificity to myelin. This study extends the ihMT quantification to the brainstem and cervical spinal cord. Sagittal EPI images were acquired after MT saturation to measure myelin content along the length of the spinal cord. Results show ihMT ratios of ~5% in the brain stem, increasing to ~6.5% in the cervical spinal cord at C3, and were consistent across healthy volunteers. Additionally, the images reveal saturation of all tissues except white matter, emphasizing the specificity of the measure.

Bhavana S. Solanky¹, Frank Riemer¹, Xavier Golay², and Claudia Angela M. Wheeler-Kingshott^1
1NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom, ²Department of Brain Repair and Rehabilitation, University College London, London, United Kingdom

²³Na-MRS has been suggested for ²³Na quantification in the spinal cord using ISIS. However, the inversion pulses of ISIS are typically long hypersecant (HS) pulses. This has implications when dealing with short T₂ metabolites such as sodium. Hence the effects of both HS and shorter sinc-guass (SG) pulses are simulated and tested in vivo. Here we present two sequences 1) a Fast HS based pulse sequence and 2) a Fast UltraShort T₂ Sensitive ISIS sequence which has the potential to be more sensitive to short T₂ components for ²³Na quantification in the spinal cord.

Alex K. Smith^1,2, Richard D. Dortch^2,3, 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, ³Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States

A method to perform qMT in the spine with a single off-resonance measurement was developed. ROIs were chosen in the lateral and dorsal columns of the spine, and in the grey matter. A single measurement model was used to fit the PSR at different off-resonance frequencies and saturation angles. The PSRs from these fits were then compared with the PSR from a full fit model. These results suggest that the PSR can be robustly quantified in healthy cervical spinal cord using only a single off-resonance measurement.

Julien Cohen-Adad¹, Wei Zhao², Anne Louise Oaklander³, Merit Cudkowicz³, Nazem Atassi³, and Lawrence L. Wald^2,4
1Department of Electrical Engineering, Ecole Polytechnique de Montreal, Montreal, Quebec, Canada, ²A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States, ³Department of Neurology, Massachusetts General Hospital, Boston, MA, United States,⁴Harvard-MIT Division of Health Sciences and Technology, MIT, cambridge, MA, United States

Recent advances in 7T MRI of the spinal cord yield images of unprecedented quality, with immediate clinical applicability and potential for new scientific understanding. Here we present clinical case studies of 7T MRI applied to spinal cord injury and amyotrophic lateral sclerosis. High spatial resolution (0.35 mm in-plane) enabled visualization of abnormalities previously unseen on the clinical scans, such as Wallerian degeneration in the injury case and degeneration of the corticospinal tracts in ALS, thus bringing relevant information to the diagnosis of the two patients.

Wendy Oakden¹, Meaghan A. O'Reilly², Margarete K. Akens^3,4, Isabelle Aubert^5,6, Cari Whyne^3,4, Kullervo Hynynen^1,2, and Greg J. Stanisz^1,2
1Medical Biophysics, University of Toronto, Toronto, ON, Canada, ²Imaging Research, Sunnybrook Research Institute, Toronto, ON, Canada, ³Orthopaedic Biomechanics Laboratory, Sunnybrook Research Institute, Toronto, ON, Canada, ⁴Department of Surgery, University of Toronto, Toronto, ON, Canada, ⁵Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada, ⁶Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada

This novel, non-invasive preclinical model uses Focused Ultrasound and microbubbles to create a highly localized injury of the rat spinal cord. The injury caused paralysis of the right hind leg in one of the rats. Quantitative T2 characterization of the injury in vivo, 24 hours following induction, revealed increased intra/extracellular water T2 indicative of inflammation, confirmed using histopathology. Diffusion tensor imaging showed decreased fractional anisotropy. Future work will look at later timepoints to determine if this injury leads to demyelination and determine the potential of this non invasive spinal cord injury model to represent clinically relevant spinal cord pathology.