Clinical Functional MRI. Presurgical Functional Neuroimaging with contributions by numerous experts Series: Medical Radiology; Subseries: Diagnostic Imaging. Christoph Stippich (Ed.) Springer 2007, 272 pages, 182 illustrations, $175.00.
Clinical Functional MRI edited by Christoph Stippich is a most timely book, which (as described by the subtitle) concentrates mainly on presurgical functional mapping. As preoperative BOLD fMRI expands more and more into the clinical arena, the information contained in a volume such as this is rapidly becoming essential to the armamentarium of any practicing neuroradiologist.
Clinical Functional MRI is divided into an introduction and nine subsequent chapters, each of which deals with an essential component of preoperative functional MRI. Each chapter is written by acknowledged experts in the field. This opus is exquisitely illustrated by 200 figures of which 151 are in color, including high resolution fMRI images, excellent drawings to illustrate key concepts and intra-operative photographs.
In the introduction (Chapter 1), Dr. Stippich gives a wonderful overview of the current status of fMRI in the clinical arena with special emphasis on intra-operative mapping. He also convincingly outlines the advantages of performing preoperative fMRI in patents with brain tumors or seizure disorder, with which I completely agree. The second chapter, entitled “Localization of brain activity using functional magnetic resonance imaging” is basically devoted to the technical aspect of fMRI including the physical principles of BOLD fMRI, physiological underpinnings of the BOLD signal (neurovascular coupling and the hemodynamic response function) and fMRI data analysis. Although some of the equations may seem daunting to clinical radiologist or neurosurgeons, this is probably necessary for completeness in a text such as this. “Functional neuroanatomy”, the third chapter, is written by two true masters in the field – Thomas P. Naidich and Tarek A. Yousry. This chapter is exquisitely illustrated with both detailed drawings and photographs of actual brains which depict the subject matter in the meticulously detailed, yet clear manner. One has almost come to expect from Dr. Naidich, the acknowledged authority of neuroradiological anatomy, including functional neuroanatomy.
The fourth chapter, “Presurgical Functional MRI in Patients with Brain Tumors” is easily the longest (almost 50 pages) and probably the most important chapter in this book. It is written by the main author of the entire volume (Dr. Stippich), and one can clearly see the care and thought which went into its writing. Stippich expertly explains the advantages of preoperative fMRI, the paradigms which he recommends and gives many other pertinent recommendations. However, a number of concepts described in this chapter are already outdated, even though the book was published in 2007. For example, in the “Legal Aspects” section, Stippich says that “fMRI is not yet a definitively established method of clinical diagnostic imaging. It should be explicitly pointed out that clinical fMRI should currently only be carried out in the framework of scientific studies.” At this time, a number of commercially available paradigm delivery systems and software which analyzes the BOLD fMRI data (as well as DTI) are available. Also, preoperative BOLD fMRI now has three established CPT codes and is regularly reimbursed by insurance companies in the United States.
Chapter 5, “Presurgical Functional MRI in Epilepsy” was reasonably complete but contained only one illustration. Chapter 6 “Functional Neuronavigation” gives a neurosurgeon’s perspective on the subject of preoperative functional MRI including multiple examples of intra-operative studies. This chapter is also valuable in the vision of the author of the hopefully not-too-distant future of preoperative fMRI. The author envisions the incorporation of other MRI data (such as perfusion MRI) as well as molecular data (PET or SPECT) as well as fMRI and DTI on a single neurosurgical navigational system platform. This cornucopia of information should serve as an accurate guide for the neurosurgeon in the resection of the tumor by depicting the various states of malignancy of the tumor as well as the essential eloquent areas of the brain adjacent to the tumor which are necessary to preserve.
Chapter 7, “Presurgical Functional Localization” written by Dr. Lehéricy et al, who are acknowledged experts in the field, contains a review of the principles of fMRI, applicability of fMRI to neurosurgical practice and a review of the limitations of the technique. The chapter draws upon the authors’ wide experience and their extensive contributions to the field. There is a brief description of diffusion tractography in preoperative mapping. Chapter 8, “Multimodality in Functional Neuroimaging” describes a number of techniques which can be combined with BOLD fMRI to assist in preoperative planning and tumor resection. These include brief overviews of diffusion tractography, MR spectroscopy, PET and MEG. Perhaps in a future edition, the topic of diffusion tractography, which is currently being incorporated more and more into preoperative and intra-operative neurosurgical guidance will be given more attention.
The ninth chapter touches upon the very exciting topic of brain plasticity. Much innovative work has recently been done in this area. The authors discuss both preoperative and postoperative plasticity in patients with brain tumors as well as reorganization of brain function due to epilepsy and congenital lesions. I may have been a bit more careful in the interpretation of fMRI studies of possible cortical plasticity due to lesion such as a stroke or a hypervascular brain tumor. BOLD fMRI is based on changes in blood flow rather than neuronal activity. Therefore, lesions which affect the blood flow will (almost by definition) affect the BOLD fMRI signal. These (as well as other important considerations) are discussed in detail in the last chapter, which I thought was outstanding and essential to anyone reading fMRI studies. The authors of this chapter discussed the myriad of possible confounding factors in interpreting fMRI studies and effectively outlined how to recognize these factors and limit them in order to correctly interpret clinical fMRI studies.
I found Clinical Functional MRI edited by Dr. Stippich to be an exceptionally useful book since it is rapidly becoming imperative for any practicing neuroradiologist to be able to accurately interpret fMRI studies while understanding their basis as well as applicability to modern neurosurgical practice. The only real criticism is based on the fact that this book was published in 2007 and I am writing this review in almost 2010. It is inevitable that there have been multiple advances in the field of preoperative fMRI, and one can hope that we will be graced by in an updated edition in the near future.
