Acute Ischemic Stroke: Imaging and Intervention

doi:10.3174/ajnr.A0628

R.G. Gonzalez, J.A. Hirsch, W.J. Koroshetz, M.H. Lev, and P. Schaefer, eds. Berlin/Heidelberg: Springer-Verlag; 2006, 268 pages, 107 illustrations, 59 tables, $129.

In the United States every year 700,000 people suffer from a new or a recurrent acute ischemic stroke, and approximately 15% die. The projected number of strokes for the year 2025 in the United States alone is close to 1.2 million. Currently, acute stroke is the third leading cause of death, the leading cause of severe disability, and a major socioeconomic problem. With the aging of the population and the higher expectations of quality of life, a concerted effort is needed among neuroscientists, emergency department physicians, neurologists, diagnostic neuroradiologists, interventional neuroradiologists, and neurointensivists to master the complex nature of acute ischemic stroke. Public education and awareness have to be an integral part of the effort, and training of physicians is critical. The incorporation of clinical findings and better understanding of neuroimaging will help to determine the treatment technique, which includes local or systemic drug delivery to dissolve the clot, devices to remove or bust the clot, and neuroprotective agents to prolong the treatment window and reduce the risk for reperfusion injury.

Although this field is moving fast with newer imaging techniques and therapeutic concepts being introduced, a publication of a book on this topic is timely. This book provides comprehensive up-to-date information, including references on acute ischemic stroke with emphasis on neuroimaging. Written by 22 diagnostic and interventional neuroradiologists and neurologists from the Massachusetts General Hospital (MGH) and faculty from the Harvard Medical School, the book reflects years of experience in the day-to-day management of a large number of acute stroke patients, as well as integration of some basic and clinical research, into a practical guide. The book is well organized into 3 parts: Part I: Fundamentals of Acute Ischemic Stroke; Part II: Imaging of Acute Ischemic Stroke; and Part III: Intervention in Acute Ischemic Stroke.

“Ischemic Stroke: Basic Pathophysiology and Neuroprotective Strategies” and “Causes of Ischemic Stroke” are the titles of the first 2 chapters of the first part of the book. The basics of the ischemic cell death and the concept of neuroprotective therapy are discussed in detail. Because the message is meant for those scientists and clinicians who are frequently involved with ischemic stroke, for nonbasic scientists and readers without sufficient background in molecular biology, these chapters would be difficult to read. Unfortunately, the few illustrations are not helpful to improve the understanding, because the legends lack suitable descriptions. A few poorly illustrated oversimplified figures also do not help the reading in the second chapter. The interested reader is referred to other more comprehensive sources on the basics and etiology of ischemic stroke.

In contradistinction, the second part, subdivided into 7 chapters, is well written and well illustrated. It covers in depth all of the currently used imaging techniques in ischemic stroke, with the exception of sonography. The first chapter, which is marked as the third chapter, in continuation to the first 2 chapters of the first part, sets the stage for imaging modalities. It outlines the techniques of CT and summarizes all of the critical imaging findings in hyperacute ischemic stroke. The second and third chapters inform us on the growing importance of CT perfusion (CTP) and CT angiography (CTA), inevitably replacing digital subtraction angiography and probably MR angiography (MRA) in ischemic stroke. Although some of the images represent brain aneurysms, which are less relevant for ischemic stroke, well-documented and -illustrated cases support detailed technical information. Advantages of CTA and CTP with the introduction of newer multidetector scanners into clinical practice and limitations, as well as pitfalls, are discussed in a well-balanced fashion. Again, some of the figures and tables are wrongly and poorly labeled. Nevertheless, this part can be highly recommended to any reader who deals with ischemic stroke in daily practice. The next 3 chapters are dedicated to MR imaging, MRA, diffusion, and perfusion MR in acute stroke. Different stages of stroke (hyperacute, acute, subacute, and chronic), including hemorrhagic transformation, are described with case examples. All of the important aspects of MR, including technical details, basics of diffusion and perfusion imaging, role of MR and MRA for treatment, and integration of an MR dataset for prediction of clinical outcome, are discussed in the most comprehensive way. The second part concludes with a short chapter on single-photon emission CT, positron-emission tomography, xenon CT, and MR spectroscopy. As outlined by the author, cost, the need for specialized equipment, and clinical limitations may all prevent their widespread use in acute ischemic stroke.

The first chapter of the last part of the book is a brief overview on the clinical management of acute stroke, including a description of the National Institutes of Health Stroke Scale. Again, the interested reader who expects more in-depth information is referred to other sources on management of acute ischemic stroke. The last chapter summarizes the current strategy in endovascular treatment of acute stroke at MGH. The authors’ approach is partly based on previous data from randomized trials (Prolyse in Acute Cerebral Thromboembolism, Emergency Management of Stroke, and Interventional Management of Stroke trials), which are summarized, or is based on their own experience. Some nicely illustrated cases support the need of further development and improvement of devices for rapid revascularization. The book concludes with an epilogue from the senior author discussing the role of CT versus MR in acute ischemic stroke. Addition of some illustrative cases would have been helpful to make the case for one or the other technique.

Being one of few comprehensive and affordable books on acute ischemic stroke, I personally enjoyed reading it, especially the imaging sections. Proper and more descriptive legends, as well as a better layout of tables, would have made the reading easier. The book predominantly addresses neuroradiologists, neurologists, and emergency department physicians and has a place in the hands of a general practicing physician who wants to better understand the evolving role of CT and MR imaging for triaging patients with acute ischemic stroke.