Quantitative Mri Of The Spinal Cord

Quantitative MRI of the Spinal Cord is the first book focused on quantitative MRI techniques with specific application to the human spinal cord. This work includes coverage of diffusion-weighted imaging, magnetization transfer imaging, relaxometry, functional MRI, and spectroscopy. Although these methods have been successfully used in the brain for the past 20 years, their application in the spinal cord remains problematic due to important acquisition challenges (such as small cross-sectional size, motion, and susceptibility artifacts). To date, there is no consensus on how to apply these techniques; this book reviews and synthesizes state-of-the-art methods so users can successfully apply them to the spinal cord. Quantitative MRI of the Spinal Cord introduces the theory behind each quantitative technique, reviews each theory’s applications in the human spinal cord and describes its pros and cons, and suggests a simple protocol for applying each quantitative technique to the spinal cord. Chapters authored by international experts in the field of MRI of the spinal cord Contains “cooking recipes —examples of imaging parameters for each quantitative technique—designed to aid researchers and clinicians in using them in practice Ideal for clinical settings

Magnetic resonance imaging (MRI) is very sensitive to the presence of damage resulting from injury or disease, but often lacks specificity. Quantitative MRI can significantly increase the specificity in the presence of pathology but must be validated, often using an animal model, for each type of injury or disease. In the case of spinal cord injury (SCI) most models are difficult to image, either due to the location of the injury, or as a result of damage to surrounding tissues resulting from invasive surgical procedures. This thesis describes a non-surgical model of rat SCI which uses MR guided focused ultrasound and microbubbles to create an injury the cervical spinal cord which is optimal for performing quantitative MRI, and compares it with other models of SCI using MRI, histology, and immunohistochemistry. It also describes the difficulties encountered when implementing the quantitative T2 (qT2) MR sequence at the very high resolution required to image the rat spinal cord, the limitations on the qT2 sequence due to the presence of diffusion, and how the effects of diffusion were minimized. Using the new SCI model and qT2 sequence, qT2 and diffusion data were acquired at 24 hours, 1 week, and 2 weeks following SCI, and the quantitative MRI parameters were correlated with histology. The increased specificity gained using quantitative MRI will increase the information available at each timepoint, reducing both the variability and cost of longitudinal studies aimed at developing treatments for SCI.

Quantitative Magnetic Resonance Imaging is a ‘go-to’ reference for methods and applications of quantitative magnetic resonance imaging, with specific sections on Relaxometry, Perfusion, and Diffusion. Each section will start with an explanation of the basic techniques for mapping the tissue property in question, including a description of the challenges that arise when using these basic approaches. For properties which can be measured in multiple ways, each of these basic methods will be described in separate chapters. Following the basics, a chapter in each section presents more advanced and recently proposed techniques for quantitative tissue property mapping, with a concluding chapter on clinical applications. The reader will learn: The basic physics behind tissue property mapping How to implement basic pulse sequences for the quantitative measurement of tissue properties The strengths and limitations to the basic and more rapid methods for mapping the magnetic relaxation properties T1, T2, and T2* The pros and cons for different approaches to mapping perfusion The methods of Diffusion-weighted imaging and how this approach can be used to generate diffusion tensor maps and more complex representations of diffusion How flow, magneto-electric tissue property, fat fraction, exchange, elastography, and temperature mapping are performed How fast imaging approaches including parallel imaging, compressed sensing, and Magnetic Resonance Fingerprinting can be used to accelerate or improve tissue property mapping schemes How tissue property mapping is used clinically in different organs Structured to cater for MRI researchers and graduate students with a wide variety of backgrounds Explains basic methods for quantitatively measuring tissue properties with MRI - including T1, T2, perfusion, diffusion, fat and iron fraction, elastography, flow, susceptibility - enabling the implementation of pulse sequences to perform measurements Shows the limitations of the techniques and explains the challenges to the clinical adoption of these traditional methods, presenting the latest research in rapid quantitative imaging which has the possibility to tackle these challenges Each section contains a chapter explaining the basics of novel ideas for quantitative mapping, such as compressed sensing and Magnetic Resonance Fingerprinting-based approaches

An array of spinal cord (SC) quantitative MRI (qMRI) techniques can measure aspects of microstructure and tissue injury. This research develops a clinically feasible multiparametric MRI protocol, including diffusion tensor imaging (DTI) fractional anisotropy (FA), magnetization transfer ratio (MTR), and measurement of SC cross-sectional area (CSA). A novel biomarker of white matter (WM) injury is also introduced, normalizing T2*WI WM signal intensity by grey matter (T2*WI WM/GM). A study of 40 healthy subjects establishes methods, normalization procedures, normative values, and reliability. 58 patients with degenerative cervical myelopathy (DCM) are studied, showing significant differences in 10 metrics. Combining these measures using multivariate methods overcomes the limitations of each technique, achieving good diagnostic accuracy and clinical correlation. T2*WI WM/GM shows strong potential as a novel biomarker, comparing favourably with established biomarkers FA and MTR. Our study of healthy subjects identifies an alarming rate of asymptomatic SC compression (ASCC) at 50%. Objective criteria and automated shape analysis are developed to create a new definition of SC compression, and qMRI demonstrates significant tissue injury in this group. This finding suggests the potential for pre-symptomatic diagnosis of DCM and other spinal pathologies. Finally, a longitudinal study compares multiparametric qMRI with clinical measures for monitoring disease progression in DCM, indicating that modified Japanese Orthopedic Association (mJOA) score is insensitive to detect progression, whereas qMRI showed tissue progression more often than comprehensive clinical assessments. These results suggest that natural history studies employing mJOA underestimate progression, due to neuroplasticity and behavioural adaptation. Combined qMRI and clinical data are now being used to inform surgical decision-making for individual patients. Reliable multiparametric assessment of SC microstructure is possible using clinically suitable methods. This approach shows strong clinical utility for individual patients, including good diagnostic accuracy, correlations with impairment, detection of tissue injury in asymptomatic individuals, and detection of progressive tissue injury in DCM patients.

Established as the leading textbook on imaging diagnosis of brain and spine disorders, Magnetic Resonance Imaging of the Brain and Spine is now in its Fourth Edition. This thoroughly updated two-volume reference delivers cutting-edge information on nearly every aspect of clinical neuroradiology. Expert neuroradiologists, innovative renowned MRI physicists, and experienced leading clinical neurospecialists from all over the world show how to generate state-of-the-art images and define diagnoses from crucial clinical/pathologic MR imaging correlations for neurologic, neurosurgical, and psychiatric diseases spanning fetal CNS anomalies to disorders of the aging brain. Highlights of this edition include over 6,800 images of remarkable quality, more color images, and new information using advanced techniques, including perfusion and diffusion MRI and functional MRI. A companion Website will offer the fully searchable text and an image bank.