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Mahmud SZ, Denney TS, Bashir A. Feasibility of spinal cord imaging at 7 T using rosette trajectory with magnetization transfer preparation and compressed sensing. Sci Rep 2023; 13:8777. [PMID: 37258697 DOI: 10.1038/s41598-023-35853-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/24/2023] [Indexed: 06/02/2023] Open
Abstract
MRI is a valuable diagnostic tool to investigate spinal cord (SC) pathology. SC MRI can benefit from the increased signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) at ultra-high fields such as 7 T. However, SC MRI acquisitions with routine Cartesian readouts are prone to image artifacts caused by physiological motion. MRI acquisition techniques with non-Cartesian readouts such as rosette can help reduce motion artifacts. The purpose of this study was to demonstrate the feasibility of high-resolution SC imaging using rosette trajectory with magnetization transfer preparation (MT-prep) and compressed sensing (CS) at 7 T. Five healthy volunteers participated in the study. Images acquired with rosette readouts demonstrated reduced motion artifacts compared to the standard Cartesian readouts. The combination of multi-echo rosette-readout images improved the CNR by approximately 50% between the gray matter (GM) and white matter (WM) compared to single-echo images. MT-prep images showed excellent contrast between the GM and WM with magnetization transfer ratio (MTR) and cerebrospinal fluid normalized MT signal (MTCSF) = 0.12 ± 0.017 and 0.74 ± 0.013, respectively, for the GM; and 0.18 ± 0.011 and 0.58 ± 0.009, respectively, for the WM. Under-sampled acquisition using rosette readout with CS reconstruction demonstrated up to 6 times faster scans with comparable image quality as the fully-sampled acquisition.
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Affiliation(s)
- Sultan Z Mahmud
- Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, USA
- Auburn University MRI Research Center, Auburn University, Auburn, AL, USA
| | - Thomas S Denney
- Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, USA
- Auburn University MRI Research Center, Auburn University, Auburn, AL, USA
| | - Adil Bashir
- Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, USA.
- Auburn University MRI Research Center, Auburn University, Auburn, AL, USA.
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Cadotte DW, Akbar MA, Fehlings MG, Stroman PW, Cohen-Adad J. What Has Been Learned from Magnetic Resonance Imaging Examination of the Injured Human Spinal Cord: A Canadian Perspective. J Neurotrauma 2019; 35:1942-1957. [PMID: 30074873 DOI: 10.1089/neu.2018.5903] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Magnetic resonance imaging (MRI) has transformed the way surgeons and researchers study and treat spinal cord injury. In this narrative review, we explore the historical context of imaging the human spinal cord and describe how MRI has evolved from providing the first visualization of the human spinal cord in the 1980s to a remarkable set of imaging tools today. The article focuses in particular on the role of Canadian researchers to this field. We begin by outlining the clinical context of traumatic injury to the human spinal cord and describe why current MRI standards fall short when it comes to treating this disabling condition. Parts 2 and 3 of this work explore an exciting and dramatic shift in the use of MRI technology to aid in our understanding and treatment of traumatic injury to the spinal cord. We explore the use of functional imaging (part 2) and structural imaging (part 3) and explore how these techniques have evolved, how they are used, and the challenges that we face for continued refinement and application to patients who live with the neurological and functional deficits caused by injury to the delicate spinal cord.
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Affiliation(s)
- David W Cadotte
- 1 University of Calgary Spine Program, Division of Neurosurgery, Department of Clinical Neurosciences, University of Calgary , Foothills Medical Centre, Calgary, Alberta, Canada
| | - M Ali Akbar
- 2 Department of Surgery, Division of Neurosurgery and Spinal Program, Toronto Western Hospital, University of Toronto , Toronto, Ontario, Canada
| | - Michael G Fehlings
- 2 Department of Surgery, Division of Neurosurgery and Spinal Program, Toronto Western Hospital, University of Toronto , Toronto, Ontario, Canada
| | - Patrick W Stroman
- 3 Centre for Neuroscience Studies, Queens University , Kingston, Ontario, Canada
| | - Julien Cohen-Adad
- 4 NeuroPoly Lab, Institute of Biomedical Engineering , Polytechnique Montreal, Montreal, Quebéc, Canada .,5 Functional Neuroimaging Unit, CRIUGM, Université de Montréal , Montreal, Quebéc, Canada
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Jia Y, Shen Z, Lin G, Nie T, Zhang T, Wu R. Lumbar Spinal Cord Activity and Blood Biochemical Changes in Individuals With Diabetic Peripheral Neuropathy During Electrical Stimulation. Front Neurol 2019; 10:222. [PMID: 30936849 PMCID: PMC6431615 DOI: 10.3389/fneur.2019.00222] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 02/20/2019] [Indexed: 02/05/2023] Open
Abstract
It is difficult to perform an in vivo evaluation of the nerve conduction mechanism in a patient with diabetic peripheral neuropathy (DPN). We aim to explore possible activation differences to enable a further understanding of the nerve conduction mechanisms of diabetic neuropathy and to present a novel clinical method to evaluate nerve injury and recovery. DPN patients (n = 20) and healthy volunteers (n = 20) were included in this study to detect the functional activation of the lumbar spinal cord via electric stimulation. Spinal fMRI data sets were acquired via a single-shot fast spin echo (SSFSE) sequence. A task-related fMRI was performed via low-frequency electrical stimulation. After post-processing, the active voxels and the percentage of signal changes were calculated for the DPN evaluation and the correlations between the blood biochemical indexes, such as glucose, total cholesterol, and hemoglobin A1c were explored. Activation in the DPN patients was primarily observed in the T12 (10/13) vertebral level. The percentage of signal changes in DPN patients was higher than that in the control group (Z = -2.757, P < 0.05). Positive correlation between the percentage of signal changes and the total cholesterol/glucose in the DNP group was found (P < 0.05). Lumbar spinal cord fMRI, based on the SEEP effect, was determined to be feasible. The repetitive activation distribution was primarily located at the T12 vertebral level. Lumbar spinal cord fMRI might be used as a potential tool to assess and reveal the nerve conduction mechanisms in DPN.
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Affiliation(s)
- Yanlong Jia
- Department of Medical Imaging, Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Zhiwei Shen
- Department of Medical Imaging, Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Guisen Lin
- Department of Medical Imaging, Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Tingting Nie
- Department of Medical Imaging, Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Tao Zhang
- Department of Medical Imaging, Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Renhua Wu
- Department of Medical Imaging, Second Affiliated Hospital, Shantou University Medical College, Shantou, China
- Provincial Key Laboratory of Medical Molecular Imaging, Shantou University Medical College, Shantou, China
- *Correspondence: Renhua Wu
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Powers JM, Ioachim G, Stroman PW. Ten Key Insights into the Use of Spinal Cord fMRI. Brain Sci 2018; 8:E173. [PMID: 30201938 PMCID: PMC6162663 DOI: 10.3390/brainsci8090173] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 08/29/2018] [Accepted: 09/06/2018] [Indexed: 01/27/2023] Open
Abstract
A comprehensive review of the literature-to-date on functional magnetic resonance imaging (fMRI) of the spinal cord is presented. Spinal fMRI has been shown, over more than two decades of work, to be a reliable tool for detecting neural activity. We discuss 10 key points regarding the history, development, methods, and applications of spinal fMRI. Animal models have served a key purpose for the development of spinal fMRI protocols and for experimental spinal cord injury studies. Applications of spinal fMRI span from animal models across healthy and patient populations in humans using both task-based and resting-state paradigms. The literature also demonstrates clear trends in study design and acquisition methods, as the majority of studies follow a task-based, block design paradigm, and utilize variations of single-shot fast spin-echo imaging methods. We, therefore, discuss the similarities and differences of these to resting-state fMRI and gradient-echo EPI protocols. Although it is newly emerging, complex connectivity and network analysis is not only possible, but has also been shown to be reliable and reproducible in the spinal cord for both task-based and resting-state studies. Despite the technical challenges associated with spinal fMRI, this review identifies reliable solutions that have been developed to overcome these challenges.
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Affiliation(s)
- Jocelyn M Powers
- Centre for Neuroscience Studies, Queen's University, Kingston, ON K7L 3N6, Canada.
| | - Gabriela Ioachim
- Centre for Neuroscience Studies, Queen's University, Kingston, ON K7L 3N6, Canada.
| | - Patrick W Stroman
- Centre for Neuroscience Studies, Queen's University, Kingston, ON K7L 3N6, Canada.
- Department of Biomedical Sciences, Queen's University, Kingston, ON K7L 3N6, Canada.
- Department of Physics, Queen's University, Kingston, ON K7L 3N6, Canada.
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Zhong XP, Chen YX, Li ZY, Shen ZW, Kong KM, Wu RH. Cervical spinal functional magnetic resonance imaging of the spinal cord injured patient during electrical stimulation. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2017; 26:71-77. [PMID: 27311305 DOI: 10.1007/s00586-016-4646-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 05/31/2016] [Accepted: 06/01/2016] [Indexed: 02/05/2023]
Abstract
PURPOSE To evaluate the spatial distribution and signal intensity changes following spinal cord activation in patients with spinal cord injury. METHODS This study used spinal functional magnetic resonance imaging (fMRI) based on signal enhancement by extra-vascular water protons (SEEP) to assess elicited responses during subcutaneous electrical stimulation at the right elbow and right thumb in the cervical spinal cord. RESULTS Seven healthy volunteers and seven patients with cervical spinal cord injury (SCI) were included in this study. Significant functional activation was observed mainly in the right side of the spinal cord at the level of the C5-C6 cervical vertebra in both the axial and sagittal planes. A higher percentage of signal changes (4.66 ± 2.08 % in injured subjects vs. 2.78 ± 1.66 % in normal) and more average activation voxels (4.69 ± 2.59 in injured subjects vs. 2.56 ± 1.13 in normal subject) in axial plane at the C5-C6 cervical vertebra with a statistically significant difference. The same trends were observed in the sagittal plane with higher percentage of signal changes and more average activation voxels, though no statistically significant difference compared with the control group. CONCLUSIONS Spinal SEEP fMRI is a powerful noninvasive method for the study of local neuronal activation in the human spinal cord, which may be of clinical value for evaluating the effectiveness of interventions aimed at promoting recovery of function using electrical stimulation.
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Affiliation(s)
- Xiao-Ping Zhong
- Department of Surgery, 2nd Affiliated Hospital of Shantou University Medical College, Shantou, 515041, Guangdong, China
| | - Ye-Xi Chen
- Department of Surgery, 2nd Affiliated Hospital of Shantou University Medical College, Shantou, 515041, Guangdong, China.
| | - Zhi-Yang Li
- Department of Surgery, 2nd Affiliated Hospital of Shantou University Medical College, Shantou, 515041, Guangdong, China
| | - Zhi-Wei Shen
- Department of Medical Imaging, 2nd Affiliated Hospital of Shantou University Medical College, Shantou, 515041, Guangdong, China.
| | - Kang-Mei Kong
- Department of Surgery, 2nd Affiliated Hospital of Shantou University Medical College, Shantou, 515041, Guangdong, China
| | - Ren-Hua Wu
- Department of Medical Imaging, 2nd Affiliated Hospital of Shantou University Medical College, Shantou, 515041, Guangdong, China
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Organization of the intrinsic functional network in the cervical spinal cord: A resting state functional MRI study. Neuroscience 2016; 336:30-38. [PMID: 27590264 DOI: 10.1016/j.neuroscience.2016.08.042] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 08/22/2016] [Accepted: 08/24/2016] [Indexed: 12/29/2022]
Abstract
Resting state functional magnetic resonance imaging (rsfMRI) has been extensively applied to investigate the organization of functional networks in the brain. As an essential part of the central nervous system (CNS), the spinal cord has not been well explored about its intrinsic functional network. In this study, we aim to thoroughly investigate the characteristics of the intrinsic functional network in the spinal cord using rsfMRI. Functional connectivity and graph theory analysis were employed to evaluate the organization of the functional network, including its topology and network communication properties. Furthermore, the reproducibility of rsfMRI analysis on the spinal cord was also examined by intra-class correlation (ICC). Comprehensive evaluation of the intrinsic functional organization presented a non-uniform distribution of topological characteristics of the functional network, in which the upper levels (C2 and C3 vertebral levels) of the cervical spinal cord showed high levels of connectivity. The present results revealed the significance of the upper cervical cord in the intrinsic functional network of the human cervical spinal cord. In addition, this study demonstrated the efficiency of the cervical spinal cord functional network and the reproducibility of rsfMRI analysis on the spinal cord was also confirmed. As knowledge expansion of intrinsic functional network from the brain to the spinal cord, this study shed light on the organization of the spinal cord functional network in both normal development and clinical disorders.
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Rempe T, Wolff S, Riedel C, Baron R, Stroman PW, Jansen O, Gierthmühlen J. Spinal fMRI reveals decreased descending inhibition during secondary mechanical hyperalgesia. PLoS One 2014; 9:e112325. [PMID: 25372292 PMCID: PMC4221460 DOI: 10.1371/journal.pone.0112325] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 10/09/2014] [Indexed: 01/31/2023] Open
Abstract
Mechanical hyperalgesia is one distressing symptom of neuropathic pain which is explained by central sensitization of the nociceptive system. This sensitization can be induced experimentally with the heat/capsaicin sensitization model. The aim was to investigate and compare spinal and supraspinal activation patterns of identical mechanical stimulation before and after sensitization using functional spinal magnetic resonance imaging (spinal fMRI). Sixteen healthy subjects (6 female, 10 male, mean age 27.2 ± 4.0 years) were investigated with mechanical stimulation of the C6 dermatome of the right forearm during spinal fMRI. Testing was always performed in the area outside of capsaicin application (i.e. area of secondary mechanical hyperalgesia). During slightly noxious mechanical stimulation before sensitization, activity was observed in ipsilateral dorsolateral pontine tegmentum (DLPT) which correlated with activity in ipsilateral spinal cord dorsal gray matter (dGM) suggesting activation of descending nociceptive inhibition. During secondary mechanical hyperalgesia, decreased activity was observed in bilateral DLPT, ipsilateral/midline rostral ventromedial medulla (RVM), and contralateral subnucleus reticularis dorsalis, which correlated with activity in ipsilateral dGM. Comparison of voxel-based activation patterns during mechanical stimulation before/after sensitization showed deactivations in RVM and activations in superficial ipsilateral dGM. This study revealed increased spinal activity and decreased activity in supraspinal centers involved in pain modulation (SRD, RVM, DLPT) during secondary mechanical hyperalgesia suggesting facilitation of nociception via decreased endogenous inhibition. Results should help prioritize approaches for further in vivo studies on pain processing and modulation in humans.
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Affiliation(s)
- Torge Rempe
- Dept of Neuroradiology, University Hospital of Kiel, Arnold-Heller-Strasse 3, Haus 41, 24105 Kiel, Germany
- Dept of Neurology, University Hospital of Kiel, Arnold-Heller-Strasse 3, Haus 41, 24105 Kiel, Germany
| | - Stephan Wolff
- Dept of Neuroradiology, University Hospital of Kiel, Arnold-Heller-Strasse 3, Haus 41, 24105 Kiel, Germany
| | - Christian Riedel
- Dept of Neuroradiology, University Hospital of Kiel, Arnold-Heller-Strasse 3, Haus 41, 24105 Kiel, Germany
| | - Ralf Baron
- Dept of Neurology, University Hospital of Kiel, Arnold-Heller-Strasse 3, Haus 41, 24105 Kiel, Germany
- Division of Neurological Pain Research and Therapy, University Hospital of Kiel, Arnold-Heller-Strasse 3, Haus 41, 24105 Kiel, Germany
| | - Patrick W. Stroman
- Centre for Neuroscience Studies, Dept of Diagnostic Radiology, Dept of Physics, 228 Botterell Hall, Queen’s University, Kingston, Ontario, Canada
| | - Olav Jansen
- Dept of Neuroradiology, University Hospital of Kiel, Arnold-Heller-Strasse 3, Haus 41, 24105 Kiel, Germany
| | - Janne Gierthmühlen
- Dept of Neuroradiology, University Hospital of Kiel, Arnold-Heller-Strasse 3, Haus 41, 24105 Kiel, Germany
- Division of Neurological Pain Research and Therapy, University Hospital of Kiel, Arnold-Heller-Strasse 3, Haus 41, 24105 Kiel, Germany
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Bosma R, Stroman P. Assessment of data acquisition parameters, and analysis techniques for noise reduction in spinal cord fMRI data. Magn Reson Imaging 2014; 32:473-81. [DOI: 10.1016/j.mri.2014.01.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 01/07/2014] [Accepted: 01/14/2014] [Indexed: 10/25/2022]
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Fratini M, Moraschi M, Maraviglia B, Giove F. On the impact of physiological noise in spinal cord functional MRI. J Magn Reson Imaging 2013; 40:770-7. [PMID: 24925698 DOI: 10.1002/jmri.24467] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 09/11/2013] [Indexed: 01/09/2023] Open
Abstract
Functional magnetic resonance imaging (fMRI) techniques are widely exploited for the study of brain activation. In recent years, similar approaches have been attempted for the study of spinal cord function; however, obtaining good functional images of spinal cord still represents a technical and scientific challenge. Some of the main limiting factors can be classified under the broad category of "physiological noise," and are related to 1) the cerebrospinal fluid (CSF) flux in the subarachnoid space surrounding the spinal cord; 2) the cord motion itself; and 3) the small area of the cord, which makes it critical to have a high image resolution. In addition, the different magnetic susceptibility properties of tissues surrounding the spinal cord reduce the local homogeneity of the static magnetic field, causing image distortion, reduction of the effective resolution, and signal loss, all effects that are modulated by motion. For these reasons, a number of methods have been developed for the purpose of denoising spinal cord fMRI time series. In this work, after a short introduction on the relevant features of the spinal cord anatomy, we review the main sources of physiological noise in spinal cord fMRI and discuss the main approaches useful for its mitigation.
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Affiliation(s)
- Michela Fratini
- MARBILab - Museo storico della fisica e Centro di studi e ricerche Enrico Fermi, Roma, Italy; Dipartimento di Fisica, Sapienza Universita' di Roma, Roma, Italy
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Wheeler-Kingshott CA, Stroman PW, Schwab JM, Bacon M, Bosma R, Brooks J, Cadotte DW, Carlstedt T, Ciccarelli O, Cohen-Adad J, Curt A, Evangelou N, Fehlings MG, Filippi M, Kelley BJ, Kollias S, Mackay A, Porro CA, Smith S, Strittmatter SM, Summers P, Thompson AJ, Tracey I. The current state-of-the-art of spinal cord imaging: applications. Neuroimage 2013; 84:1082-93. [PMID: 23859923 DOI: 10.1016/j.neuroimage.2013.07.014] [Citation(s) in RCA: 155] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Revised: 06/30/2013] [Accepted: 07/04/2013] [Indexed: 12/14/2022] Open
Abstract
A first-ever spinal cord imaging meeting was sponsored by the International Spinal Research Trust and the Wings for Life Foundation with the aim of identifying the current state-of-the-art of spinal cord imaging, the current greatest challenges, and greatest needs for future development. This meeting was attended by a small group of invited experts spanning all aspects of spinal cord imaging from basic research to clinical practice. The greatest current challenges for spinal cord imaging were identified as arising from the imaging environment itself; difficult imaging environment created by the bone surrounding the spinal canal, physiological motion of the cord and adjacent tissues, and small crosssectional dimensions of the spinal cord, exacerbated by metallic implants often present in injured patients. Challenges were also identified as a result of a lack of "critical mass" of researchers taking on the development of spinal cord imaging, affecting both the rate of progress in the field, and the demand for equipment and software to manufacturers to produce the necessary tools. Here we define the current state-of-the-art of spinal cord imaging, discuss the underlying theory and challenges, and present the evidence for the current and potential power of these methods. In two review papers (part I and part II), we propose that the challenges can be overcome with advances in methods, improving availability and effectiveness of methods, and linking existing researchers to create the necessary scientific and clinical network to advance the rate of progress and impact of the research.
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Affiliation(s)
- C A Wheeler-Kingshott
- NMR Research Unit, Queen Square MS Centre, UCL Institute of Neurology, London, England, UK.
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Kornelsen J, Smith SD, McIver TA, Sboto-Frankenstein U, Latta P, Tomanek B. Functional MRI of the thoracic spinal cord during vibration sensation. J Magn Reson Imaging 2012; 37:981-5. [PMID: 23011888 DOI: 10.1002/jmri.23819] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 08/14/2012] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To demonstrate that it is possible to acquire accurate functional magnetic resonance images from thoracic spinal cord neurons. MATERIALS AND METHODS The lower thoracic spinal dermatomes (T7-T11) on the right side of the body were mechanically stimulated by vibration for 15 participants. Neuronal responses to vibration sensation were measured in the thoracic spinal cord using a HASTE sequence on a 3 Tesla MRI system. RESULTS Signal increases were observed in the corresponding lower thoracic spinal cord segments ipsilateral to the side of stimulation in the dorsal aspect of the spinal cord. CONCLUSION This is the first study to provide proof of principle that functional imaging of the entire thoracic spinal cord is possible, by detecting neuronal activity in the thoracic spinal cord during sensory stimulation using spinal fMRI.
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Affiliation(s)
- Jennifer Kornelsen
- National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada.
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Cadotte DW, Bosma R, Mikulis D, Nugaeva N, Smith K, Pokrupa R, Islam O, Stroman PW, Fehlings MG. Plasticity of the injured human spinal cord: insights revealed by spinal cord functional MRI. PLoS One 2012; 7:e45560. [PMID: 23029097 PMCID: PMC3446947 DOI: 10.1371/journal.pone.0045560] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 08/20/2012] [Indexed: 12/14/2022] Open
Abstract
Introduction While numerous studies have documented evidence for plasticity of the human brain there is little evidence that the human spinal cord can change after injury. Here, we employ a novel spinal fMRI design where we stimulate normal and abnormal sensory dermatomes in persons with traumatic spinal cord injury and perform a connectivity analysis to understand how spinal networks process information. Methods Spinal fMRI data was collected at 3 Tesla at two institutions from 38 individuals using the standard SEEP functional MR imaging techniques. Thermal stimulation was applied to four dermatomes in an interleaved timing pattern during each fMRI acquisition. SCI patients were stimulated in dermatomes both above (normal sensation) and below the level of their injury. Sub-group analysis was performed on healthy controls (n = 20), complete SCI (n = 3), incomplete SCI (n = 9) and SCI patients who recovered full function (n = 6). Results Patients with chronic incomplete SCI, when stimulated in a dermatome of normal sensation, showed an increased number of active voxels relative to controls (p = 0.025). There was an inverse relationship between the degree of sensory impairment and the number of active voxels in the region of the spinal cord corresponding to that dermatome of abnormal sensation (R2 = 0.93, p<0.001). Lastly, a connectivity analysis demonstrated a significantly increased number of intraspinal connections in incomplete SCI patients relative to controls suggesting altered processing of afferent sensory signals. Conclusions In this work we demonstrate the use of spinal fMRI to investigate changes in spinal processing of somatosensory information in the human spinal cord. We provide evidence for plasticity of the human spinal cord after traumatic injury based on an increase in the average number of active voxels in dermatomes of normal sensation in chronic SCI patients and an increased number of intraspinal connections in incomplete SCI patients relative to healthy controls.
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Affiliation(s)
- David W. Cadotte
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Department of Surgery, Division of Neurosurgery, Toronto Western Hospital, Toronto, Ontario, Canada
- Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - Rachael Bosma
- Centre for Neuroscience Studies, Queen’s University, Kingston, Ontario, Canada
| | - David Mikulis
- Department of Radiology, Division of Neuroradiology, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Natalia Nugaeva
- Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
| | - Karen Smith
- Providence Health Care, Spinal Rehabilitation Unit, Kingston, Ontario, Canada
| | - Ronald Pokrupa
- Division of Neurosurgery, Kingston General Hospital, Queen’s University, Kingston, Ontario, Canada
| | - Omar Islam
- Department of Radiology, Division of Neuroradiology and Head & Neck Imaging, Kingston General and Hotel Dieu Hospitals, Queen’s University, Kingston, Ontario, Canada
| | - Patrick W. Stroman
- Centre for Neuroscience Studies, Queen’s University, Kingston, Ontario, Canada
- Departments of Diagnostic Radiology and Physics, Queen’s University, Kingston, Ontario, Canada
| | - Michael G. Fehlings
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Department of Surgery, Division of Neurosurgery, Toronto Western Hospital, Toronto, Ontario, Canada
- Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
- Division of Genetics and Development, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
- * E-mail:
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