Dr. Germano has put together a snapshot of the techniques available in the fast-moving field of image-guided neurosurgery. This volume is aimed at the practicing neu-rosurgeon, focusing on the nuts and bolts of image-guided surgery and, for the most part, foregoing theory and mathematical equations. Written with clear explanations of technical terms, the book is well within the grasp of a practicing neurosurgeon or neurosurgical resident with no prior experience with image-guided surgery. Image-guided surgery is seductive. On a glossy screen, the surgeon is shown a high-quality rendition of the brain or the spine, and as he or she moves an instrument, the position of the instrument is clearly noted on the screen. The problem is that the virtual image on the screen may have nothing to do with reality. This volume will afford the reader the practical knowledge he or she needs to confront the problems associated with image-guided surgery. This book is divided into three sections: Principles and Technology, Cranial Applications, and Spine Applications. Following a chapter on historical perspective is a chapter entitled “Source of Error in Image Registration for Cranial Image-Guided Neurosurgery.” It cuts to the heart of the problem, outlining sources of distortion during image acquisition, image registration, and intraoperative brain deformation. I think that this chapter is worth the price of the book. The authors of this chapter lay out in very simple terms the major sources of error in registering the virtual image on the screen with reality. I hoped that the subsequent chapters would address the source and avoidance of errors in a similar fashion, but, unfortunately, that is not always the case. The remaining chapters in the section Principles and Technology are descriptions of various systems and components used for image-guided surgery. Some of these chapters are simply step-by-step directions for the use of a particular system. In other chapters the authors offer pertinent advice that will help the reader optimize the efficacy of a particular system. The section Cranial Applications consists of seven chapters addressing various aspects of image-guided cranial surgery. This section includes solid chapters on image-guided brain biopsy, cerebrovascular applications of image-guided surgery, image-guided brain tumor resection, and image-guided epilepsy surgery. Two chapters, “Intraoperative Image Update by Interface with Ultrasound” and “Intraoperative Image Update by Magnetic Resonance Imaging,” are insightful reviews of these two new directions in image-guided surgery. The chapter entitled “New Directions in Atlas-Assisted Stereotactic Functional Neurosurgery” is an outstanding review of the stereotactic atlases available to the practicing functional neurosurgeon. Included in this chapter are descriptions of three-dimensional atlases and a probabilistic functional atlas that incorporates high-quality brain mapping data from multiple patients. The section Spinal Applications covers the use of intraoperative imaging for cervical instrumentation, thoracic instrumentation, and lumbar instrumentation as well as instrumentation for scoliosis. An additional chapter discusses virtual fluoroscopy, a technique that has become very popular with spine surgeons because it moves the cumbersome fluoroscopic unit out of the operating field, limits the radiation exposure of the surgeon, and obviates the need for a special preoperative study. All surgeons performing image-guided surgery should have access to this volume. While a few of the chapters are mundane, many of the chapters are the best reviews available in the field. The chapters are concise and clearly written, affording a quick review of the topic.