MR Imaging in White Matter Diseases of the Brain and Spinal Cord

M. Filippi, N. DeStefano, V. Dousset, and J.C. McGowan, eds. New York: Springer-Verlag; 2005, 478 pages, 610 illustrations, $279.

White matter lesions are ubiquitous and are the most common findings on brain MR imaging. This often leads to a laundry list of differential etiologic possibilities. Consequently, publications that attempt to clarify these findings and add more specificity to the diagnoses are welcome. MR Imaging in White Matter Diseases of the Brain and Spinal Cord is a relatively short, multiauthored (55 contributors) book that attempts to bring within a single volume these many diseases and their imaging appearances. In many respects, it succeeds.

The book is long on the general physics of MR and advanced applications of MR (nearly a third of the book) but short on pathologic correlates of most of the diseases illustrated. Many of the diseases described and illustrated would have benefited from inclusion of the pathologic counterparts (either histologic or gross anatomic). I was able to find illustrated pathology in just a few instances: for example in Balo concentric sclerosis; the histology and electron microscopy of the primary angiitis; the histology of 3 grades of gliomas and pleomorphic xanthroastrocytoma. This should not, however, be considered a major drawback of the book; it is mentioned with the hope that future editions of the book will include more of this type of material.

There are 5 major sections in the book: “MR Techniques and Principles,” “Disorders of Myelination,” “Demyelinating Diseases,” “Immune-Mediated Disorders,” “White Matter Disorders Related with Aging,” and “White Matter Changes Secondary to Other Conditions.” Multiple chapters, from 3 to 10, comprise each section.

The first third of the book, contains material on the physics of MR contrast, hardware considerations (magnets, shielding, gradient coils, radiofrequency coils, and so forth), spin-echo and gradient-echo imaging, concepts in fast imaging, magnetization transfer, diffusion imaging, perfusion imaging, functional MR, MR spectroscopy, and high-field MR. Although all of this material is readily available in other textbooks, the authors presumably felt the need to describe these basic principles for those readers who may have had little to no previous experience with MR. Some of these chapters are more complete than others but, in any event, should serve as basic introductory information.

The strength of the book lies in the clinical imaging and its description. Charles Raybaud, on MR imaging of brain development, describes the problems involved in imaging premature and term infants in addition to presenting sound material on fetal brain imaging and developing/maturation of white matter. This chapter would have been strengthened by more information and illustrations of diffusion-weighted imaging and spectroscopy in infants. “Imaging of Inherited and Acquired Metabolic Brain Disorders,” by Mauricio Castillo, is a good survey of these diseases and fortunately contains some spectra obtained in some patients (Canavan disease, adrenoleukodystrophy, Wilson disease). He rightly divides these entities into those associated with head sizes that are normal, enlarged, or small—this is certainly the most logical approach to these diseases, because there are similarities in their white matter abnormalities. Greater in-depth discussion of MR spectroscopy in metabolic disorders is contained in a chapter by Nicola DeStefano and Marzia Mortilla. Although this is a short chapter (12 pages), the reader is exposed to issues other than single voxel technique, such as chemical shift imaging, metabolic maps, and multivoxel analysis in MR spectroscopy. The demyelinating diseases naturally constitute a large part of the book, with, of course, multiple sclerosis (MS) leading the way. MS is discussed in 3 chapters: routine imaging, newer techniques, and variants of MS. Adequate clinical information supplements the imaging features and that helps to bring the MR findings down to clinical realities. Because most MR findings in MS are well known, the chapter by Jack Simon and Bette De Masters is particularly welcome. Here the authors nicely describe some of the historic background to what have been termed MS variants such as Devic, Schilder, Marburg, and Balo concentric sclerosis. The chapter goes a long way in clarifying what these diseases represent and how they present clinically and their MR imaging. It was particularly refreshing that in this chapter, as in some other chapters, radiologists coauthored the material with their clinical counterparts. Neuroradiologists will benefit from the side-by-side presentation of the imaging/clinical/pathologic features of these unusual diseases. Reinforced are a number of facts—such as why it is important from a treatment standpoint to distinguish Devic from MS where there can also be involvement of the cord and optic nerve, what the pathologic difference is between MS and Devic, and how magnetization transfer may potentially be used to distinguish common MS from Devic. In a similar manner the authors describe what the apparent differences are between Marburg disease and acute MS. It is not this reviewer’s intent to dwell on this chapter, but it is discussed here because it shows the value of tight neuropathologic correlations, such as what stains and histologic characteristics enable the distinction between differing levels of demyelinating activity. Throughout this chapter, where MS variants are described, the differential diagnoses and the difficulties that arise in these cases are discussed.

In the chapter on acute disseminated encephalomyelitis (ADEM), in addition to describing the imaging and clinical features, the authors do try to come to grips with the issue of whether ADEM is an MS variant or a separate disease entity. This issue is troubling because, as the authors mention, as many as one third of patients initially diagnosed as having ADEM eventually are diagnosed with MS.

A separate section of the book deals with immune-mediated disorders and their affect on white matter. Included are chapters on primary CNS angiitis, systemic lupus erythematosus, noninflammatory diseases of the CNS, which may affect areas of the brain other than white matter such as Beçhet disease, antiphospholipid antibody syndrome, and Sjogern syndrome. The chapters on the normal aging brain and the ever-present white matter abnormalities in cerebrovascular disease (leukoaraiosis) received special attention; these are clearly important issues, because all interpreters of MR constantly wonder whether the amount of white matter disease is in keeping with the patient’s age or reflects some subclinical vascular disease. Other subjects covered well include chapters on viral diseases in immunocompetent and immunocompromised patients, white matter changes in neoplastic disease (which incidentally includes examples of multi-voxel magnetic resonance spectroscopy to show metabolic alterations in surrounding white matter, in addition to demonstrating perfusion MR and functional MR). Head trauma and psychiatric disorders round out the book.

In summary, this text brings under one roof the imaging concepts involved in evaluating white matter disease. It successfully integrates clinical and imaging information and can, for that reason, be recommended as a reference text for a departmental library.