Clinical MR Neuroimaging: Diffusion, Perfusion and Spectroscopy

Jonathan Gillard, Adam Waldman, and Peter Barker, eds. Cambridge: Cambridge University Press; 2005, 852 pages, $330.

The newly published Clinical MR Neuroimaging: Diffusion, Perfusion and Spectroscopy, edited by Jonathan Gillard, Adam Waldman, and Peter Barker, brings under one title a review of many of the advanced techniques and their applications in neuro MR imaging. This is multiauthored text with 80 contributors, both MR physicists and clinical neuroradiologists, who have special expertise in the use of state-of-the-art MR applications.

The book is divided into 8 sections, the first of which is entitled “Physiologic MR Techniques.” This section gives the basic background information which is needed to appreciate the 7 sections that follow, because these 7 sections are disease-oriented and involve primarily the implementation of advanced techniques in each disease category.

In this era of a plethora of case-based textbooks, it is important to have on hand a text that immediately immerses the reader into advanced techniques, precluding material on routine MR imaging. This was a wise decision by the editors because material on the basics of MR abound. Because this type of MR information is not included, the reader must have a basic understanding of MR physics beforehand. Therefore, the book begins (section 1) with the fundamentals of MR spectroscopy, followed sequentially by quantification, analysis, and pitfalls of MR spectroscopy. The same pattern is repeated for diffusion imaging (fundamentals, tractography, artifacts, and pitfalls) and cerebral perfusion (perfusion with exogenous contrast agents, rCBF with arterial spin-labeling, and artifacts and pitfalls in MR perfusion). Thus, in the first 160 pages, the reader receives the basic information needed to appreciate the clinical material which follows in the 3 major foci of the book—spectroscopy, diffusion, and perfusion. Each area is written with the practicing radiologist in mind with good drawings and easy to follow text.

The following areas are discussed in separate sections: cerebrovascular disease; adult neoplasia; infection/inflammation/demyelination; seizure disorders; psychiatric and neurodegenerative diseases; trauma; and pediatrics. Conspicuously absent is a separate chapter on spine (there is only a brief mention of the spine in the demyelination chapter), and, because of this, the book should have been entitled Clinical MR Brain Imaging. Although it is recognized that minimal clinical material has been accumulated by using advanced techniques in the spine, there have been reports of application of diffusion imaging tractography, CSF flow studies, and even functional MR (fMR) imaging of the spinal cord, all of which should have been incorporated into a short chapter. It is hoped that in a future edition that the editors will consider this important area of neuroimaging.

Each of the 7 sections start off with a brief introduction called an “overview,” and then each chapter begins with a summary of the chapter entitled “key points.” There are straightforward descriptions of the techniques with clinical examples, ending with a separate section called “case studies.” The print is large, the text uncluttered, and the image quality by and large is excellent, though a few images are unnecessarily dark. Each contributor’s style varies, but what makes a few chapters enjoyable is the posing of questions, many of which are often raised in the context of clinical imaging such as, “does diffusion-weighted imaging differentiate transient ischemic attack from stroke?” or “how long do diffusion-weighted imaging and apparent diffusion coefficient values remain abnormal in acute stroke?” It would have been even better had every chapter contained a number of these questions followed by an appropriate discussion of the interrogative.

In the 7 clinical sections, the concepts are simply and briefly expressed, with the inclusion of some of the latest concepts and techniques. The book addresses many issues that probably do not bother MR physicists but may occasionally stump the radiologist, such as why the apparent diffusion coefficient is a rotationally variant measure or how the PROPELLER acquisition samples K-space or the basis for giving twice the amount of contrast material when using spin-echo perfusion imaging compared with gradient-echo perfusion imaging. There are other abundant examples like this throughout the book. For those who wish to delve more deeply into the basics of these techniques, the references will be of assistance.

The bulk of the book (the last 3 quarters) is devoted to applying the lessons learned in the first quarter of the book to various diseases. The imaging of stroke is treated in a complete manner; it is interesting that the last chapter in this section concerns the imaging of migraines, showing among other parameters, magnetoencephalography, fMR, magnesium maps, and alterations in n-acetyl asparate during visual stimulation.

In the relatively short adult neoplasia section, equal attention and space is given to MR spectroscopy, diffusion, and perfusion. Spectroscopy naturally deals with single voxel, multivoxel, and spectroscopic imaging; for details on MR spectroscopy, the reader will have to refer to the first section of the book. This very basic chapter is written primarily to give the clinical neurologist a flavor of the potential value of MR spectroscopy. Although brevity is important, this reviewer feels that the neoplasm chapter overdoes brevity and the reader is left with “bare bones” MR spectroscopy. As a result, some of the case study examples are not explained in the depth they should have been. For example, the 72 multivoxel MR spectroscopy in a case of GBM does not have the various peaks explained. The chapters on diffusion and perfusion in tumors do have more in-depth material than the spectroscopy chapter.

The section on infection, inflammation, and demyelination follows the same pattern of overview (Dr. Zimmerman’s contribution is incidentally a useful overview of the subject), and MR spectroscopy/diffusion-weighted imaging (separately for infection and inflammation). In the MR spectroscopy chapter in cranial infection, the authors should have paid closer attention to the legends. For example, they describe a herpes infection extending into the “frontal region” when clearly the extension is into the occipital region. Better descriptions in the legends of the pulse sequences used in every MR spectroscopy would have added significantly to the descriptive material. Good clinical examples including wide ranging pathology are presented. There is a nice final chapter by Drs. Chang and Ernest (both of whom are well-known investigators in HIV) on physiologic MR to evaluate HIV-associated disorders. The remaining chapters on seizures, psychiatric and neurodegenerative disorders, and trauma are basically surveys of these fields. The chapter on pediatrics, however, is more extensive (156 pages), informative, and useful than the preceding 3 chapters. Here Drs. Melham and Gotay present a nice survey of physiologic MR of the pediatric brain.

Overall, the book is highly readable and the image quality is good throughout, though a few images are unnecessarily dark. There are advanced techniques that are not included in this book, such as fMR (cortical activation), time-resolved MR angiography, and CSF flow studies, but of course it was the author’s intent to concentrate just on the application of MR spectroscopy, diffusion, and perfusion in brain MR imaging. Perhaps future editions will include these newer areas of MR interest.

The book is recommended as an excellent description of advanced techniques in clinical settings and will be useful to all practicing neuroradiologists.