Multiparametric Quantitative MRI of the Cervical Spinal Cord to Measure Microstructure and Tissue Injury

Multiparametric Quantitative MRI of the Cervical Spinal Cord to Measure Microstructure and Tissue Injury
Author: Allan Russell Martin
Publisher:
Total Pages:
Release: 2017
Genre:
ISBN:

Download Multiparametric Quantitative MRI of the Cervical Spinal Cord to Measure Microstructure and Tissue Injury Book in PDF, Epub and Kindle

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.

MULTIPARAMETRIC MRI OF THE PEDIATRIC SPINAL CORD

MULTIPARAMETRIC MRI OF THE PEDIATRIC SPINAL CORD
Author: Shiva Shahrampour
Publisher:
Total Pages: 0
Release: 2023
Genre:
ISBN:

Download MULTIPARAMETRIC MRI OF THE PEDIATRIC SPINAL CORD Book in PDF, Epub and Kindle

Quantitative magnetic resonance imaging (MRI) measurements of the pediatric spinal cord is important for both diagnostic and treatment planning. In recent years several quantitative MRI (qMRI) techniques that have been developed and tested to measure functional and structural information of the spinal cord tissue and microstructure. Several of the existing structural and functional imaging biomarkers (i.e., diffusion tensor imaging (DTI)) have demonstrated potential for providing microstructural information about the spinal cord. However, due to the lack of a standard anatomical template of the pediatric spinal cord, quantification of the spinal cord tissue has been challenging. Therefore, one of the goals of this work is to develop and test tools for quantification as well as the creation of a standard structural template of the typically developing (TD) pediatric spinal cord. This will allow automated measurement of normative values of the spinal cord cross-sectional area (SCCSA) at various levels of the spinal cord. Furthermore, to examine the white matter (WM) microstructure of the pediatric cord we developed a processing pipeline for the atlas-based generation of TD pediatric spinal cord WM tracts. This will facilitate the measurements of normative diffusion values for various WM tracts.A group of 30 TD subjects (age range of 6-17 years old (12.38 ±2.81)), who had no evidence of spinal cord injury or pathology were recruited. We utilized a multiparametric MRI protocol, including high-resolution T2-w structural and diffusion-weighted MRI images to scan the subjects on a 3T MRI scanner. The diffusion data were acquired using a novel iFOV DTI sequence. For quantification, a post-processing pipeline was utilized to generate the structural pediatric template. Next, WM tracts were generated using an atlas-based approach, and diffusion metrics (FA, MD, RD and AD) were quantified in 34 tracts identified in the processing pipeline. Normative SCCSA and DTI diffusion indices were generated for the TD population. Lastly, we demonstrated that DTI indices (i.e. FA) can be a predictive measure of components of the clinical test for spinal cord injury, as well as an indicator of the white matter tracts integrity. Therefore, in the final step of this work, we expanded our quantitative analysis to look at the microstructural and macrostructural changes in 15 children with chronic spinal cord injury (SCI) (AIS A-D, mean age of 12.8 ± 3.1 years). This included measurements of SCCSA, diffusion metrics and T2* WM/GM ratio of various white matter tracts in the patient population. We also examined the relationships between all the metrics and the ISNCSCI clinical scores in SCI subjects. We then compared these measurements between the TD and SCI patients to evaluate the diagnostic utility of these techniques and biomarkers. Statistically significant difference was observed between the two populations in the studied metrics. The results show that the proposed techniques may have the potential to be used as surrogate biomarkers for the quantification of the injured spinal cord. Keywords: diffusion tensor imaging, typically developing, spinal cord injury, spinal cord cross-sectional area, fractional anisotropy, mean diffusivity, axial diffusivity, radial diffusivity.

Quantitative MRI of the Spinal Cord

Quantitative MRI of the Spinal Cord
Author: Julien Cohen-Adad
Publisher: Academic Press
Total Pages: 331
Release: 2014-01-16
Genre: Medical
ISBN: 0123972825

Download Quantitative MRI of the Spinal Cord Book in PDF, Epub and Kindle

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

Quantitative Magnetic Resonance Imaging

Quantitative Magnetic Resonance Imaging
Author: Nicole Seiberlich
Publisher: Academic Press
Total Pages: 1094
Release: 2020-11-18
Genre: Computers
ISBN: 0128170581

Download Quantitative Magnetic Resonance Imaging Book in PDF, Epub and Kindle

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

Traumatic Brain and Spinal Cord Injury

Traumatic Brain and Spinal Cord Injury
Author: Cristina Morganti-Kossmann
Publisher: Cambridge University Press
Total Pages: 361
Release: 2012-07-19
Genre: Medical
ISBN: 1107007437

Download Traumatic Brain and Spinal Cord Injury Book in PDF, Epub and Kindle

Presents the most up-to-date clinical and experimental research in neurotrauma in an illustrated, accessible, comprehensive volume.

MRI of the Lung

MRI of the Lung
Author: Hans-Ulrich Kauczor
Publisher: Springer Science & Business Media
Total Pages: 315
Release: 2008-11-12
Genre: Medical
ISBN: 354034618X

Download MRI of the Lung Book in PDF, Epub and Kindle

During the past decade significant developments have been achieved in the field of magnetic resonance imaging (MRI), enabling MRI to enter the clinical arena of chest imaging. Standard protocols can now be implemented on up-to-date scanners, allowing MRI to be used as a first-line imaging modality for various lung diseases, including cystic fibrosis, pulmonary hypertension and even lung cancer. The diagnostic benefits stem from the ability of MRI to visualize changes in lung structure while simultaneously imaging different aspects of lung function, such as perfusion, respiratory motion, ventilation and gas exchange. On this basis, novel quantitative surrogates for lung function can be obtained. This book provides a comprehensive overview of how to use MRI for imaging of lung disease. Special emphasis is placed on benign diseases requiring regular monitoring, given that it is patients with these diseases who derive the greatest benefit from the avoidance of ionizing radiation.

Small Animal Imaging

Small Animal Imaging
Author: Fabian Kiessling
Publisher: Springer
Total Pages: 871
Release: 2017-05-22
Genre: Medical
ISBN: 3319422022

Download Small Animal Imaging Book in PDF, Epub and Kindle

This textbook is a practical guide to the use of small animal imaging in preclinical research that will assist in the choice of imaging modality and contrast agent and in study design, experimental setup, and data evaluation. All established imaging modalities are discussed in detail, with the assistance of numerous informative illustrations. While the focus of the new edition remains on practical basics, it has been updated to encompass a variety of emerging imaging modalities, methods, and applications. Additional useful hints are also supplied on the installation of a small animal unit, study planning, animal handling, and cost-effective performance of small animal imaging. Cross-calibration methods and data postprocessing are considered in depth. This new edition of Small Animal Imaging will be an invaluable aid for researchers, students, and technicians involved in research into and applications of small animal imaging.

Magnetic Resonance Elastography

Magnetic Resonance Elastography
Author: Sudhakar K. Venkatesh
Publisher: Springer
Total Pages: 143
Release: 2014-10-01
Genre: Medical
ISBN: 1493915754

Download Magnetic Resonance Elastography Book in PDF, Epub and Kindle

The first book to cover the groundbreaking development and clinical applications of Magnetic Resonance Elastography, this book is essential for all practitioners interested in this revolutionary diagnostic modality. The book is divided into three sections. The first covers the history of MRE. The second covers technique and clinical applications of MRE in the liver with respect to fibrosis, liver masses, and other diseases. Case descriptions are presented to give the reader a hands-on approach. The final section presents the techniques, sequence and preliminary results of applications in other areas of the body including muscle, brain, lung, heart, and breast.