Clearly structured, each chapter describes: * clinical features and laboratory investigations * pathology * pathogenetic considerations * therapy * case presentation * MRI and spectroscopy of a specific myelin disorder Completely updated and expanded by 20 chapters to include the latest information on: - inborn errors of metabolism and neurodegenerative disorders - the role of subcellular structures - enzyme biochemistry - the pathophysiological mechanisms of posthypoxic-ischemic cerebral damage - inflammatory and infectious disorders Plus: Greater coverage of the genetic and pathophysiological mechanisms underlying white matter disorders. Finally: 250 high-quality illustrations depict rare disorders which previously were only described.

Our thanks go to our colleagues at the VU Univer- Preface to the Third Edition sity Medical Center and to those in other hospitals Reading through the prefaces of the two previous edi- who referred their patients to us. We are indebted to tions,we can say that much of what was said there still all colleagues who allowed us to use their MR images, holds. At the same time,however,much has changed. published or unpublished,making it possible for us to There has been immense progress in the technical present illustrations of nearly all known white matter possibilities of magnetic resonance and in the know- disorders. Two colleagues were particularly helpful ledge of genetic defects, biochemical abnormalities, and provided us with essential and unpublished f- and cellular processes underlying myelin disorders. ures: our friends Susan Blaser,from the Hospital for This immense progress has prompted us to embark Sick Children in Toronto,and Zoltán Patay,from the upon the enormous task of rewriting the previous King Faisal Hospital in Riyadh. edition and adding 40 chapters. In doing so we have Many people at the VU University Medical Center tried to cover most white matter disorders,hereditary have been of great technical help to us in producing and acquired,and to present a collection of images to high quality images and in providing secretarial illustrate the field to the fullest possible extent. This assistance. The contributions of these people are edition will therefore be more complete than the pre- mentioned separately in the acknowledgements.

This is the second, completely rewritten edition of the widely acclaimed book on MR of myelin, myelination and myelin disorders (1989). In the last five years many new data became available with regard to genetics, molecular biology, the role of cellular substructures on one side and on the other side regarding the growing experience with MR patterns of less common myelin disorders. Not only, therefore, the text has been updated, but many new chapters have been added on disorders of which previously the white matter involvement was less clear. The acquired myelin disorders were reorganized and their backgrounds were more extensively elucidated, to place the MR examinations in the clinical context where they belong.

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

This book offers practical guidelines for performing efficient and cost-effective MRI examinations. By adopting a practical protocol-based approach the work-flow in a MRI unit can be streamlined and optimized. All chapters have been thoroughly reviewed, and new techniques and figures are included. There is a new chapter on MRI of the chest. This book will help beginners to implement the protocols and will update the knowledge of more experienced users.

Major depressive disorder (MDD) is a debilitating psychiatric condition and a leading contributor to the global burden of disease. Characterizing MDD-related abnormalities in neurobiological processes will inform more comprehensive etiological frameworks of MDD that will facilitate the development of more targeted approaches to the prevention and identification of, and intervention for, this disorder. In this context, one promising biological target is myelin, a specialized biological tissue and fundamental facilitator of neuronal communication. Myelin ensheaths axons and facilitates saltatory conduction of electrical signaling in the nervous system. Postmortem studies of brains of depressed individuals, and non-human animal, genetic, and neuroimaging studies suggest that abnormalities in myelin are associated with MDD. Growing evidence suggests that neural activity and myelin influence each other to support an effective nervous system, and that stress-related neuroinflammation may result in the degradation of myelin in MDD. Brain regions implicated in this research, and in MDD more generally, include the nucleus accumbens (NAcc) and the dorsolateral prefrontal cortex (DLPFC), core regions involved in reward and cognitive control processes, respectively. Recent developments in quantitative magnetic resonance imaging (qMRI) allow for improved assessment of myelin content at the whole brain level, in vivo, in humans through the measure of R1. In this study we used qMRI to measure R1 to examine whether the brains and, in particular, the NAcc and DLPFC, of individuals diagnosed with MDD are characterized by reductions in myelin content compared to individuals without a history of psychiatric disorder (i.e., healthy controls [CTLs]). We found that the MDD group had lower levels of myelin than did the CTL group at the whole brain level and in the NAcc. Furthermore, myelin content of the DLPFC was reduced in MDD participants who had experienced a greater number of depressive episodes compared to both MDD participants who had experienced fewer depressive episodes and participants in the CTL group. Taken together, these results offer new evidence that MDD is characterized by reduced myelin content of the brain and in the NAcc in particular, and that the chronicity of MDD is associated with reduced myelin in the DLPFC. While further research is needed to elucidate the role of myelin in influencing affective, cognitive, behavioral, and clinical aspects of MDD, the current study provides important evidence that a fundamental property of brain composition, myelin, is altered in this disorder.