Richard D. Dortch^1,2, Adrienne N. Dula^1,2, Ke Li^1,2, Jane A. Hirtle², Catherine E. Frame^2,3, Pooja Gaur^2,4, John C. Gore^1,2, and Seth A. Smith^1,2
1Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, ²Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ³Radiation Oncology, Vanderbilt University, Nashville, TN, United States, ⁴Chemical and Physical Biology, Vanderbilt University, Nashville, TN, United States

Magnetization transfer (MT) imaging has been used to assess macromolecular content in the brain; yet, similar studies in the spinal cord have been limited. The difficulties associated with spinal cord imaging include high-resolution demands. Therefore, we have developed a novel protocol for high-resolution quantitative MT imaging of the human cervical spinal cord at 7 T. Data were collected in healthy volunteers via a selective inversion recovery sequence. Macromolecular to free proton pool size ratios were consistent with reported values at lower field strengths, suggesting that qMT imaging can be performed in the human cervical spinal cord at ultra-high field.

Linqing Li¹, Yazhuo Kong¹, Jonathan Brooks¹, Karla Miller¹, and Peter Jezzard^1
1FMRIB, Clinical Neurology Department, University of Oxford, Oxford, United Kingdom

DANTE pulse trains (a rapid series of low flip angle RF pulses interspersed with gradients) can attenuate moving CSF signal and preserve most of the static tissue signal. Here, we propose a method that employs DANTE preparation for CSF flow suppression in multi-slice spinal cord fMRI. Compared to a conventional EPI spinal cord sequence, the temporal variance within the spinal cord was decreased. Improved activation patterns were observed using a block-design finger tapping task.

Virginie Callot¹, Mohamed Tachrount¹, Jérôme Laurin², André Mauès de Paula³, Tanguy Marqueste², Patrick Decherchi², Patrick J Cozzone¹, and Guillaume Duhamel^1
1CRMBM, CNRS, Aix-Marseille Univ, Marseille, France, ²ISM, CNRS, Aix-Marseille Univ, Marseille, France, ³Service d’Anatomie Pathologique, Hôpital de la Timone, AP-HM, Marseille, France

In this work, a multimodal MRI approach, including diffusion tensor imaging, perfusion imaging and MR spectroscopy, was applied in a follow-up study dedicated to the characterization of posttraumatic events consecutive to moderate and severe mouse spinal cord contusion injury. Vascular, structural and metabolic MR parameters were observed to vary with a time course and a spatial extent dependant on the impact force, and in correlation with immunohistochemistry and developed force. The sensitivity and specificity of the proposed MR multimodal approach should help to define the most relevant markers of disease and progression. Moreover, discriminant analysis should permit to establish diagrams describing the cascade of posttraumatic events.

Irene M Vavasour¹, Sandra M Meyers², Erin L MacMillan³, Burkhard Maedler⁴, David KB Li¹, Marcel F Dvorak^5,6, Talia Vertinsky⁷, Vic Venu⁷, Alexander Rauscher⁸, Alex L MacKay^1,2, and Armin Curt^9
1Radiology, University of British Columbia, Vancouver, British Columbia, Canada, ²Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada, ³Clinical Research, University of Bern, Bern, Switzerland, ⁴Neurosurgery, University of Bonn, Bonn, Germany, ⁵Orthopaedics, University of British Columbia, Vancouver, British Columbia, Canada, ⁶International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada, ⁷Radiology, Vancouver General Hospital, Vancouver, British Columbia, Canada, ⁸UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada, ⁹Spinal Cord Injury Center, University of Zurich, Zurich, Switzerland

With cervical spondylotic myelopathy (CSM), spinal cord (SC) damage is caused by narrowing (“stenosis”) of the spinal canal. The relationship between cord motion and CSM symptoms are unknown. Thirteen CSM subjects and 15 controls underwent velocity imaging using 3D phase-contrast around the stenosis or C5. Tibial and ulnar nerve somatosensory evoked potentials (SSEP) were also measured. Displacement was significantly different between controls and CSM subjects. No significant correlations were found between displacement and clinical scores, however, abnormal SSEP was associated with increased SC movement. Increased SC motion may relate to underlying pathophysiological mechanisms that contribute to SC function deterioration.

Issel Anne L. Lim^1,2, Ann S. Choe^3,4, Xu Li^2,5, Craig K. Jones^2,5, and Peter C. M. van Zijl^2,5
1Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States, ²F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, United States, ³International Center for Spinal Cord Injury, Hugo Moser Research Institute at Kennedy Krieger Inc, Baltimore, Maryland, United States, ⁴Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States, ⁵Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States

A primary component of quantitative susceptibility mapping (QSM) is determining the resonance frequency per voxel. In the spinal cord, obtaining frequency maps from phase images via traditional gradient echo imaging (GRE) is complicated due to low SNR and many phase wraps at tissue interfaces of large susceptibility differences. By measuring resonance frequency maps with the WAter Saturation Shift Referencing (WASSR) method and fitting the resulting signal as a function of offset frequency to a Lorentzian lineshape, voxel frequencies can be determined without the need for phase unwrapping. WASSR allowed good quality frequency maps to be obtained in the spinal cord.

Paulina Rosicka^1,2, Jie Liu³, Andrew C. Yung⁴, Wolfram Tetzlaff³, and Piotr Kozlowski^3,4
1Institute of Nuclear Physics, Krakow, Poland, ²UBC MRI Research Centre, Vancouver, BC, Canada, ³ICORD, ⁴UBC MRI Research Centre

Myelin water imaging was carried out in rat spinal cords in vivo. CPMG data were acquired from 10 rats 3 weeks and 8 weeks following dorsal column trancection injury and ex vivo. Average Myelin Water Fraction was measured in fasciculus gracilis 5 mm cranial to injury and correlated with histology. MWF increased at 3 weeks post injury and returned to baseline levels at 8 weeks post injury. Eriochrome stain (EC) showed similar trend, while dgen-MBP (dye staining degenerated myelin) showed increased values between 3 and 8 weeks post-injury. MWF values correlated well with EC stain, but not with the dgen-MBP stain.

Bhavana Shantilal Solanky¹, Khaled Abdel-Aziz², Marios Yiannakas¹, Olga Ciccarelli², and Claudia A. M. Wheeler-Kingshott^1
1NMR Research Unit, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom, ²NMR Research Unit, Department of Brain Repair and Rehabilitaion, UCL Institute of Neurology, London, United Kingdom

Here we demonstrate quantitative measurements of the Glutamate/Glutamine complex (Glx) in the cervical spinal cord of healthy controls using 1H MRS at 3T. Sequences readily available were compared for the measure of Glutamate and Glx in the spinal cord, a challenging region of interest due to its small volume, B0 inhomogeneities, and physiological motion. A short TE PRESS, and STEAM sequence were both tested. LCmodel was used to obtain measures for the reliability of the Glx fit (CRLB %) and concentrations. A reliable fit was found in all subjects using PRESS (CRLB<20%). No reliable Glx fits were achieved using STEAM.

Dhanashree Vernekar¹, Wenshu Qian¹, Zhongping Zhang¹, Pek-Lan Khong¹, and Mina Kim^1
1Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, Hong Kong, China

Diffusion tensor imaging (DTI) has been used to successfully show changes in white matter structure and connectivity in spinal cord of patients with various diseases. However, spinal cord DTI is still in its infancy due to technical challenges including intrinsically low signal-to-noise ratio. Here we propose to use a nonlocal means Rician noise filter to enhance the accuracy of tensor estimation and obtain robust DTI-derived measures. Our results show that Rician denoising can significantly decrease erroneous tensor estiamtions with reduced mean Chi-square up to 43% over without Rician denoising.

Paola Valsasina¹, Maria A. Rocca², Dusan Damjanovic², Sarlota Mesaros³, Mark A. Horsfield⁴, Tatjana Stosic-Opincal⁵, Jelena Drulovic³, Giancarlo Comi⁶, and Massimo Filippi^1
1Neuroimaging Research Unit, Institute of Experimental Neurology, San Raffaele Scientific Institute and Vita-Salute San Raffaele University, Milan, Italy, Italy, ²Neuroimaging Research Unit, Institute of Experimental Neurology, San Raffaele Scientific Institute and Vita-Salute San Raffaele University, Milan, Italy, ³Clinic of Neurology, Faculty of Medicine, University of Belgrade, Belgrade, Yugoslavia, ⁴Medical Physics Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom, ⁵Clinic of Radiology, Faculty of Medicine, University of Belgrade, Belgrade, Yugoslavia,⁶Department of Neurology, San Raffaele Scientific Institute and Vita-Salute San Raffaele University, Milan, Italy, Italy

We applied an active surface method to perform a voxel-based analysis of cervical cord atrophy and lesion location in patients with multiple sclerosis (MS) and different phenotypes. Sagittal dual-echo and MP-RAGE cervical cord scans were acquired from 89 MS patients and 31 healthy controls [HC]. Patients with clinically isolated syndrome showed no cord atrophy, while primary-progressive (PP) MS had diffuse cord atrophy vs. HC. Several clusters of cord atrophy were found in secondary-progressive MS vs. relapsing-remitting MS, benign MS, and PPMS. Cord lesions were more frequent in the posterior cord portion and in the cord segments from C1 to C4.

Bhavana Shantilal Solanky¹, Frank Riemer¹, Xavier Golay², and Claudia A. M. Wheeler-Kingshott^1
1NMR Research Unit, Department of Neuroinflammation, UCL Institute of Neurology, London, Greater London, United Kingdom, ²Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, Greater London, United Kingdom

The potential of following the dynamics of sodium ions in diseased populations provides a huge drive for the development of quantitative sodium MRI in the brain. Many diseases also potentially involve sodium channels in other areas of the central nervous system (CNS), such as the spinal cord. However, due to the intrinsically low signal to noise of sodium images and the small size of spinal cord sodium MRI here is lacking. Here we investigate the feasibility of sodium MR Spectroscopy (MRS) in the cervical spinal cord at 3T in view of studying the dynamics of sodium in this challenging area.