Quantitative MRI of the Spinal Cord

Table of Contents

Cover image

Title page

Copyright

Dedication

Preface

Contributors

Acknowledgements

Introduction to “Quantitative MRI of the Spinal Cord”

Part I Quantitative Biomarkers in the Spinal Cord: what for?

Chapter 1.1. Rationale for Quantitative MRI of the Human Spinal Cord and Clinical Applications

1.1.1 Introduction

1.1.2 Quantitative MRI Techniques

1.1.3 Application of Quantitative MRI Techniques to Spinal Cord Disease

1.1.4 Conclusions and Future Directions

Chapter 1.2. Inflammatory Demyelinating Diseases

1.2.1 Introduction

1.2.2 Classification of Inflammatory Myelopathies

1.2.3 Transverse Myelitis: A Practical Definition Based on MRI

1.2.4 The Significance of TM and Its Relationship to MS and NMO

1.2.5 Neuromyelitis Optica: The First Demyelinating Disease with a known Serum Marker

1.2.6 MRI of the Spinal Cord: Qualitative versus Quantitative Imaging

1.2.7 Magnetization Transfer MRI Studies of the Spinal Cord

1.2.8 Diffusion-Weighted Imaging Studies in the Spinal Cord

1.2.9 MR Spectroscopy

1.2.10 Relaxometry in the Spinal Cord: T1 Mapping

1.2.11 Measurements and Significance of Spinal Cord Atrophy

1.2.12 Conclusions

Chapter 1.3A. Traumatic Spinal Cord Injury

1.3A.1 Introduction

1.3A.2 Message 1: Animal Models That Link Pathology of Acute Spinal Cord Injury to MR Signal Characteristics

1.3A.3 Message 2: Quantitative MSCC and MCC

1.3A.4 Message 3: MRI Signal Characteristics after Acute Traumatic Spinal Cord Injury: What is the Sensitivity and Specificity of Determining Neurologic Function at the Time of Injury and for Predicting Long-Term Prognosis?

1.3A.5 Conclusions

Chapter 1.3B. Traumatic Spinal Cord Injury

1.3B.1 Introduction

1.3B.2 Neurophysiology and MRI: Complementary Approaches

1.3B.3 Morphological Changes in the Spinal Cord after SCI

1.3B.4 Relationship between Neurological Recovery and Morphological Changes

1.3B.5 The MRI Paradox: When Anatomical Changes Do Not Correspond to Functional Changes

1.3B.6 Conventional MRI Approaches in SCI Clinical Trial Management

1.3B.7 Future Directions of MRI and SCI

1.3B.8 Conclusions

Part II Physics of MRI

Chapter 2.1. Array Coils

2.1.1 Introduction

2.1.2 Coil Theory

2.1.3 Array Coils

2.1.4 Evaluation of Tx Array Coils

2.1.5 Evaluation of Rx Array Coils

2.1.6 Conclusion

Chapter 2.2. B0 Inhomogeneity and Shimming

2.2.1 Background

2.2.2 Field Inhomogeneities in the Human Spinal Cord

2.2.3 Shim Hardware

2.2.4 Tune-up, Static, and Dynamic Shim

2.2.5 Measurement of the Field Distribution

2.2.6 Shim Algorithms

2.2.7 Shim Practice

2.2.8 Specific Problems and Solutions for T2∗-Weighted Acquisitions

2.2.9 Specific Problems and Solutions for Diffusion-Weighted Acquisitions

2.2.10 Specific Problems and Solutions for MRS

2.2.11 Summary

Chapter 2.3. Susceptibility Artifacts

2.3.1 Introduction: Sources of Susceptibility Artifacts

2.3.2 Artifacts in EPI of the Spinal Cord

2.3.3 Methods to Reduce Susceptibility Artifacts

2.3.4 Comparison of Methods to Reduce Susceptibility Artifacts

2.3.5 Conclusion

Chapter 2.4. Ultra-High Field Spinal Cord Imaging

2.4.1 Background

2.4.2 Anatomical MRI

2.4.3 Quantitative MRI

2.4.4 BOLD Functional MRI

2.4.5 Magnetic Resonance Spectroscopy

2.4.6 Concluding Remarks

Part III Imaging Spinal Cord Structure

Chapter 3.1. Diffusion-Weighted Imaging of the Spinal Cord

3.1.1 Principles of Diffusion-Weighted Magnetic Resonance Imaging

3.1.2 Modeling the Diffusion Properties

3.1.3 Data Acquisition

3.1.4 Data Processing

3.1.5 Tractography

3.1.6 Quantify DWI Metrics in the Spinal Cord

3.1.7 Diffusion Characteristics of the Neurologically Intact Spinal Cord

3.1.8 Diffusion Characteristics following Spinal Cord Trauma

3.1.9 Recipes for Implementation of Clinical Diffusion Imaging of the Spinal Cord

Chapter 3.2. Q-Space Imaging

3.2.1 Q-Space Theory

3.2.2 Free, Hindered, and Restricted Diffusion

3.2.3 Q-Space Imaging

3.2.4 Limitations of QSI

3.2.5 Acquisition of QSI Data in the Spinal Cord

3.2.6 Data Processing

3.2.7 Current In Vivo Spinal Cord Application of QSI

3.2.8 Conclusion

Chapter 3.3. Advanced Methods to Study White Matter Microstructure

3.3.1 Introduction: Diffusion Imaging and Tissue Microstructure

3.3.2 Advanced Methods for Studying White Matter

3.3.3 Applications in Spinal Cord

3.3.4 Summary

Chapter 3.4. Magnetization Transfer

3.4.1 The MT Phenomenon and Its Relationship to Myelin

3.4.2 MT Contrast and MTR

3.4.3 Measuring MT in the Spinal Cord

3.4.4 MT Acquisition Protocols

3.4.5 Quantitative Models of MT

3.4.6 MT Data Analysis Methods

3.4.7 Chemical Exchange Saturation Transfer

3.4.8 Conclusion

Chapter 3.5. T2 Relaxation

3.5.1 Overview

3.5.2 T2 Relaxation in CNS Tissue

3.5.3 Preclinical T2 Relaxation Studies in the Spine

3.5.4 Human T2 Relaxation Studies in the Spinal Cord

3.5.5 How to Collect and Analyze T2 Data from the Spinal Cord

3.5.6 Concluding Remarks

Chapter 3.6. Atrophy

3.6.1 Historical Perspective

3.6.2 MRI Scanning Considerations

3.6.3 Semiautomated Atrophy Measurement

3.6.4 Toward the Fully Automated

3.6.5 Gray and White Matter Volumentry

3.6.6 What Should We Measure?

3.6.7 The Clinical Need for Atrophy Measurement

3.6.8 Summary

Part IV Imaging Spinal Cord Function

Chapter 4.1. Spinal Cord fMRI

4.1.1 Blood Oxygenation Level Dependent

4.1.2 Challenges in fMRI of the Spinal Cord

4.1.3 Data Acquisition

4.1.4 Data Processing

4.1.5 Conclusions

4.1.6 Recipe

Chapter 4.2. Physiological Noise Modeling and Analysis for Spinal Cord fMRI

4.2.1 What is Physiological Noise?

4.2.2 Time Domain Filtering

4.2.3 Approaches for Reducing the Effects of Physiological Noise

4.2.4 Modeling Physiological Noise

4.2.5 Group Analysis

4.2.6 Defining a Statistical Threshold (p-Value)

4.2.7 Conclusions

Chapter 4.3. Mapping the Vasculature of the Spinal Cord

4.3.1 Rationale

4.3.2 Vascular Anatomy

4.3.3 MR Angiography

4.3.4 Inlet Arteries or Outlet Veins?

4.3.5 Spinal Cord Veins and the BOLD Effect

4.3.6 Outlook

Part V Spectroscopy

Chapter 5.1. Single Voxel MR Spectroscopy in the Spinal Cord

5.1.1 Magnetic Resonance Spectroscopy

5.1.2 1H MRS in the Spinal Cord

5.1.3 Technical Issues

5.1.4 Non-Proton MRS of the Spinal Cord

5.1.5 Recommended Protocol

Annex: Anatomy of the Spinal Cord

Index