Vascular Alterations and Recruitment in Spinal Cord Injury Revealed by Multislice Arterial Spin Labeling (ASL) Perfusion Imaging
Guillaume Duhamel¹, Tanguy Marqueste², Michaël Sdika¹, Mohamed Tachrount¹, Patrick Decherchi², Patrick J. Cozzone¹, Virginie Callot^1
1CRMBM / CNRS 6612, Faculté de Médecine, Université de la Méditerranée, Marseille, France; ²ISM, Université de la Méditerranée, Marseille, France

The combination of diffusion tensor imaging (DTI) and perfusion imaging has the potential to be a useful tool in spinal cord injury (SCI) investigation. Assessment of mouse SC blood flow (SCBF), recently demonstrated to be feasible by flow-sensitive alternating inversion recovery arterial spin labeling (FAIR-ASL), was based on single slice technique. However, multislice perfusion imaging matching DTI acquisitions would be required for lesion characterization. We then modified the original FAIR sequence to a FAIR-QUIPPSSII sequence, multislice compatible and optimized to mouse SC, and applied it along with DTI in a follow-up study performed over time on mice having received SCI.

Quantification of Spinal Cord Blood Volume in Humans Using VASO MRI
Jinsoo Uh¹, Yan Cao², Hanzhang Lu^1
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; ²Department of Mathematical Sciences, University of Texas at Dallas, Dallas, TX, United States

We have developed a technique based on Vascular-Space-Occupancy (VASO) MRI to measure spinal cord blood volume. The VASO sequence has been carefully adjusted to deal with the challenging aspects in imaging spinal cord such as small dimensions, tissue inhomogeneities, and cord motions. We compared two VASO protocol schemes and the one using multiple spin echoes showed better performance. The scBV values with this protocol were 1.8±0.2 ml/100 ml tissue for gray matter and 1.1±0.1 for white matter. To our knowledge, this is the first report of blood volume in gray and white matters of human spinal cord.

Rapid Three-Dimensional Myelin Water Fraction Imaging of the Cervical Spinal Cord
Shannon Kolind^1,2, Sean Deoni^2
1FMRIB Centre, University of Oxford, Oxford, United Kingdom; ²Centre for Neuroimaging Sciences, King's College London, London, United Kingdom

The pathology of myelin in spinal cord disease is poorly understood due to the technical challenges of measuring myelin noninvasively. Our goal was to assess the efficacy of multi-component Driven Equilibrium Single Pulse Observation of T₁ and T₂ (mcDESPOT) for obtaining high spatial resolution spinal cord myelin water fraction (MWF) data covering the entire cervical spinal cord. Our results demonstrated the ability to reliably acquire high quality MWF data, at a spatial resolution of 1x1x1.5mm over a 12x12x18cm field-of-view, with MWF values consistent with prior literature values and a coefficient of variation of less than 3%.

Correlating Spinal Cord Diffusion Tensor Imaging Metrics to Clinical Measures in Patients with Adrenomyeloneuropathy
Aliya Gifford¹, Kathy Zackowski^2,3, Joseph Wang², Peter C.M. van Zijl^4,5, Gerald Raymond^1,3, Seth Smith^6,7
1Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, MD, United States; ²Motion Analysis Laboratory, Kennedy Krieger Institute, Baltimore, MD, United States; ³Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD; ⁴Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; ⁵F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States; ⁶Vanderbilt University Institute of Imaging Science, Nashville, TN, United States; ⁷Department of Radiology, Vanderbilt University, Nashville, TN, United States

Pathologic changes in adrenomyeloneuropathy (AMN) are associated with the spinal cord and characterized by primary distal axonopathy with secondary demyelination.  We hypothesized that diffusion tensor imaging (DTI) metrics correlate with the disease severity and neurological and physiological deficits.  Nine healthy volunteers and 40 AMN patients (20 M, 20 F) were imaged at 3T.  DTI-derived metrics were measured for the upper cervical spine.  Functional measures of sensation were found to correlate significantly (p<0.01) with diffusivity in the dorsal column.  These results support a strong structure-function relationship between the DTI-derived metrics of the spinal cord and clinical dysfunction.

Independent Spinal Cord Atrophy Measures Correlate to Motor and Sensory Deficits in Individuals with Spinal Cord Injury
Henrik Lundell^1,2, Dorothy Barthelemy², Arnold Skimminge¹, Fin Biering-Sørensen³, Jens Bo Nielsen^2
1Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; ²Department of Excercise and Sport Sciences & Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark; ³Clinic for Spinal Cord Injuries, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark

MRI can effectively detect lesions on the spinal cord but it has been difficult to find sensitive markers for specific functional deficits. Spinal cord atrophy due to loss of white matter can be measured as the transversal area at a given level of the spinal cord distal to the focal lesion and correlations to global functional scores has been observed in different pathologies. We suggest a simple but robust method to extract more specific and functionally relevant parameters and show independent correlations to motor and sensory deficits in individuals with spinal cord injury.

ASIA Scores Correlate with DTI Metrics in Non-Hemorrhagic Traumatic C-Spine Injury
Rao Gullapalli^1,2, Jiachen Zhuo^1,2, Sendhil Cheran¹, K. Shanmuganathan¹, S. Mirvis^1
1Radiology, University of Maryland School of Medicine, Baltimore, MD, United States; ²Core for Translational Research in Imaging at Maryland (C-TRIM), University of Maryland School of Medicine, Baltimore, MD, United States

There has been rising interest in evaluation spinal cord injury using diffusion tensor imaging (DTI) for accurate characterization of cord injury.  The purpose of our retrospective study was to determine the correlation between American Spine Injury Association (ASIA) clinical injury motor score in patients with traumatic cervical cord injury and the various DT-MRI parameters.  Our results indicate that DTI parameters accurately depict the severity of the injury and correlates with the ASIA scores.  Further, among non-hemorrhagic cord contusions there appears to be a strong correlation of ASIA scores with the DTI parameter.

Wide-Band Steady State Free Precession with Small Diffusion Gradients for Spine Imaging: Application to Superior Nerve Visualization
Ehud J. Schmidt¹, Ajit Shankaranarayanan², Sylvain Jaume^1,3, Giovanna Danagoulian¹, Srinivasan Jr. Mukundan¹, Krishna S. Nayak^4
1Radiology, Brigham and Womens Hospital, Boston, MA, United States; ²GE Healthcare Applied Science Lab, Menlo Park, CA, United States; ³Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, Cambridge, MA, United States; ⁴Electrical Engineering, University of Southern California

3D High-resolution Wide-band Steady State Free Precession (WBSSFP) is utilized to track nerves as they exit the spinal cord. By placing the readout direction in the Superior-Inferior direction, small diffusional effects (B=40-60 s/mm2) contribute to improved contrast between Cerebro-spinal-fluid or Fat and the nerves, and remove vessel signal. In six patients with degenerative spine disease, WBSSFP aided in the diagnosis of back-pain sources, by detecting impingement on the nerves outside the spinal dura, not easily detected with conventional T2-,T1- or T2*-weighted sequences.

High Resolution Anatomical Imaging of the Spinal Cord at 7 T
Eric Edward Sigmund¹, Caixia Hu¹, Giselle Suero¹, Joseph Helpern^1
1Radiology, New York University Langone Medical Center, New York, NY, United States

This work presents results of novel coil development and protocol optimization for imaging of the spinal cord at the ultra-high field 7 T platform.  A single-channel loop coil and a 4-chanel cervical spine cradle array were employed for anatomical c-spine imaging, using standard T2-weighted FLASH and TSE protocols.  High resolution results were obtained allowing clear gray/white matter differentiation as well as depiction of small secondary structures (denticulate ligament, nerve roots, rostral-caudal vasculature).  The enhanced level of detail provided by the combination of high field and coil engineering may be useful for monitoring neuropathy, injury, or surgical planning.

MRI Correlates of White Matter Structure in Intact Myelin Vs. Myelin Debris –ex Vivo Study in Injured Rat Spinal Cord
Henry S. Chen¹, Jie Liu², Wolfram Tetzlaff², Piotr Kozlowski
¹University of British Columbia, Vancouver, British Columbia, Canada; ²International Collaboration On Repair Discoveries

Diffusion tensor imaging, quantitative T2, and T1 mapping were used to characterize excised rat spinal cord samples at 3 weeks post injury. Comparisons were made between injured and controlled white matter for several MR parameters, as well as for optical and electron microscopy cross-sections. Axonal damage is demonstrated by decrease in longitudinal diffusivity and fraction anisotropy, while myelin damage is more difficult to assess due to the presence of myelin debris. However the result did show increased myelin water content which is consistent with the histology result which showed increased spacing between myelin bi-layers in myelin debris.

Angiopoietin-1 Reduces Blood-Spinal Cord Barrier Permeability and Lesion Volume in the Acute Phase of Spinal Cord Injury: MRI and Histological Studies
Chirag B. Patel¹, Ponnada A. Narayana^1
1Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, Houston, TX, United States

We hypothesized that attenuation of blood-spinal cord barrier (BSCB) compromise with angiopoietin-1 (Ang1) acutely after spinal cord injury (SCI) would reduce the severity of secondary pathologies (e.g., BSCB permeability and SCI lesion volume) in the acute phase of injury. The hypothesis was tested quantitatively in an experimental rat model of thoracic level 7 contusion SCI using the following methodologies: dynamic contrast-enhanced (DCE)-MRI, high resolution anatomical MRI, and immunofluorescence histology. A significant reduction in BSCB permeability and lesion volume during the acute phase of injury was observed as a result of Ang1 treatment. Histology validated DCE-MRI findings.