Advanced Spinal Cord Imaging
Thursday 23 April 2009
Room 313A 10:30-12:30


Claude H. Manelfe and Madja Thurnher

10:30 629. Feasibility of Evaluating the Spinal Cord with MR Elastography
    Scott A. Kruse1, Arunark Kolipaka1, Armando Manduca1, Richard L. Ehman1
Radiology, Mayo Clinic, Rochester, MN, USA
    The goal of this work was to investigate the feasibility of applying MR Elastography to evaluate the spinal cord. An acoustic driver device placed posterior to the spine was evaluated in seven volunteer studies. An inversion algorithm based on flexural vibration in beams was used to process the wave data. The shear stiffness of the superior portion of the spinal cord was estimated to be 12.1+2.4 kPa in the resulting elastograms, while the bulk stiffness of the cauda equina estimated at 2.7+0.8 kPa. This work may provide new parameters for characterizing the spinal cord in health and disease.
10:42 630. Structural and Hemodynamic Mouse Spinal Cord Maturation Assessed by High Resolution Diffusion Tensor Imaging (DTI) and Arterial Spin Labeling (ASL)
    Virginie Callot1, Guillaume Duhamel1, Patrick J. Cozzone1
UMR 6612 CNRS, Université de la Méditerranée, Centre de Résonance Magnétique Biologique et Médicale (CRMBM), Marseille, France
    The early organization of the spinal cord (SC) gray and white matter is not well described although important for the sensory-motor development. In this work, we performed a preliminary DTI and ASL-based perfusion study on mice, from weanling to young adult age, to investigate whether the MR methods would be sensitive enough to assess evolving structural and hemodynamic patterns. High-resolution quantitative images have been obtained and sensitivity was sufficient to observe evolution of the metrics with time. The capability of measuring non-invasively developmental changes in spinal cord should help as a basis for understanding atypical spine development and spine diseases.
10:54 631. Quantitative Evaluation of Diffusion Tensor Imaging at 3T in the Cervical Spinal Cord of Patients with Adrenomyeloneuropathy
    Aliya Gifford1, Seth A. Smith2,3, Ali Fatemi1,2, SakkuBai Naidu2,4, Peter C. van Zijl2,3, Gerald V. Raymond1,4
Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, MD, USA; 2F.M. Kirby Research Center, Kennedy Krieger Institute, Baltimore, MD, USA; 3Russel H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA; 4Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
    Diffusion tensor imaging (DTI) may be sensitive to changes in tissue microstructure and therefore is useful in quantitatively assessing pathway-specific changes known, pathologically, to exist in the cervical spinal cord of adrenomyeloneuropathy patients. We acquired DTI of the cervical cord in nine healthy volunteers and twenty AMN patients. Lateral and dorsal columns were reconstructed and DTI-derived metrics analyzed for the C1-C3 cervical segment. Results show an increase in perpendicular diffusivity from 0.52 (controls) to 0.57 (AMN) (P<0.3). These observations are in agreement with expectations from pathology indicating demyelination, suggesting that quantitative DTI analysis may enhance clinical evaluation of this disease.
11:06 632. High-Resolution in Vivo MR Imaging of the Human Spinal Cord at 7 Tesla
    Kyongtae Ty Bae1,2, Chan-Hong Moon1, Jung-Hwan Kim1, Sung-Hong Park1,2
Radiology, University of Pittsburgh, Pittsburgh, PA, USA; 2Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
    We have developed MR surface coil and imaging technique suitable for high-resolution human spinal cord imaging at 7 T. Our method was applied to depiction of the gray (GM) and white matter (WM) of the cervical spinal cord on T1-weighted inversion recovery image which is reported superior to other sequences for the evaluation of spinal cord lesions in multiple sclerosis. Preliminary results indicate spinal cord imaging at 7T allows excellent visualization and differentiation of GM and WM due to greatly increased signal-to-noise ratio (SNR).
11:18 633. Diffusion-Weighted Imaging of the Spine with Readout-Segmented (RS)-EPI
    Samantha J. Holdsworth1, Roland Bammer1, Stefan Skare1
Lucas MRS/I Center, Stanford University, Stanford, CA, USA
    The development of diffusion-weighted imaging (DWI) of the spine has been hindered by the large off-resonance effects problematic for single-shot EPI. Interleaved EPI can be used to reduce image artifacts, however, in the presence of motion, it can lead to undersampling of k-space and corresponding image ghosting. Readout-segmented (RS)-EPI has recently been shown to be a promising alternative pulse sequence for high-resolution DWI of the human brain, which has significantly reduced distortions. The objective of this study was to compare DW images acquired with RS-EPI and EPI. Here we produce images with significantly reduced distortions compared with EPI, and demonstrate distortion-corrected RS-EPI spine data.
11:30 634. Effect of VEGF Treatment on the Blood-Spinal Cord Barrier Permeability in Experimental Spinal Cord Injury: Dynamic Contrast-Enhanced Magnetic Resonance Imaging
    Chirag B. Patel1, David M. Cohen1, Pallavi Ahobila-Vajjula1, Laura M. Sundberg1, Tessy Chacko1, Ponnada A. Narayana1
Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston, Houston, TX, USA
    Compromised blood-spinal cord barrier (BSCB) is a factor in the outcome following spinal cord injury (SCI). Vascular endothelial growth factor (VEGF) promotes angiogenesis and vascular permeability. Dynamic contrast-enhanced MRI (DCE-MRI) studies were performed to track spatiotemporal changes in BSCB permeability following acute administration of VEGF in SCI. BSCB permeability was greater at all time points in VEGF-treated animals compared to controls. VEGF hastened neurobehavioral recovery by day 28 post-SCI but this improvement did not persist by day 56 post-SCI. Changes in the BSCB permeability do not appear to be the primary driving factors for VEGF's observed treatment effects in SCI.
11:42 635. Radial Fractional Anisotropy Mean and Angular Fractional Anisotropy Mean: New Tools in the Diagnosis and Assessment of Spinal Cord
    Arturo Cárdenas-Blanco1,2, Harrison Westwick1,2, Kareem Andre Moran3, Eve Chung Tsai2,4
Division of Neuroscience, Ottawa Health Research Institute, Ottawa, Ontario, Canada; 2University of Ottawa, Ottawa, Ontario, Canada; 3Medical School, University of Ottawa, Ottawa, Ontario, Canada; 4Neurosurgery, Ottawa Hospital, Ottawa, Ontario, Canada
    During the last years, Diffusion Tensor Imaging (DTI) has become the preferred tool to analyze white matter properties in spinal cord by depicting qualitatively its response to the presence of pathological lesions. In this abstract a new approach to quantitatively assess spinal cord tissue is proposed. This approach is based in the measurement of Radial Fractional Anisotropy Mean (RFAM) and Angular Fractional Anisotropy Mean (AFAM) values which depict the changes in fractional anisotropy mean values as a function of the distance from the centre of the spinal cord and the angle respectively.
11:54 636. In Vivo Diffusion Tensor Imaging in Rat Model of Chronic Spinal Cord Compression
    Matthew Man Hin Cheung1,2, Darrell T.H. Li3, Edward S. Hui1,2, Abby Y. Ding1,2, Yong Hu3, Ed X. Wu1,2
Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China; 2Laboratory of Biomedical Imaging and Signal Processing , The University of Hong Kong, Hong Kong SAR, China; 3Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong SAR, China
    We have employed DTI to investigate the pathophysiology of chronic spinal cord compression in this study. Average diffusion characteristic curves and fiber tracking have been done to evaluate the lesion and intact regions. DTI is sensitive to the damage and it is potential to monitor the progressive structural and functional changes in such chronic spinal cord diseases.
12:06 637. In Vivo MRS Monitor Delayed Neurodegeneration in Experimental Spinal Cord Injury
    Junchao Qian1, Juan Herrera1, Ponnada Narayana1
Diagnostic and Interventional Imaging, University of Texas at Houston, Houston, TX, USA
    In vivo proton MRS studies were performed in injured spinal cord at two weeks post-injury. Spectra were acquired at the epicenter, rostral and caudal to the site of injury. A reduction in the NAA levels was observed at all the three segments. This study demonstrates delayed neurodegeneration away from the epicenter of injury.
12:18 638. Evaluation of Q-Ball Metrics for Assessing the Integrity of the Injured Spinal Cord
    Julien Cohen-Adad1,2, Hugues Leblond2, Aurobrata Ghosh3, Maxime Descoteaux4, Rachid Deriche3, Habib Benali1, Serge Rossignol2
INSERM, Univ Paris 6, Pitie Salpetriere Hospital, Paris, France; 2GRSNC, Physiology department, Univ Montreal, Montreal, QC, Canada; 3Odyssée Project Team, INRIA, Sophia Antipolis, France; 4Neurospin, NMR Lab, CEA, Gif-sur-Yvette, France
    Previous studies showed how metrics derived from diffusion tensor imaging (DTI) are useful to quantify spinal cord integrity following injury. However, DTI model may not be optimal for complex diffusion profiles, where less constraining techniques such as q-ball imaging (QBI) would be more adapted. In this study, we applied QBI in cats with partial spinal cord injury and we compared various QBI quantitative metrics to that ones already used in DTI. We also propose an original QBI-based metric to quantify the homogeneity of diffusion directions. Results show the benefits of QBI metrics to quantitatively study spinal cord microstructure.