Abstract—In this paper, we describe an extrinsic-point-based, interactive image-guided neurosurgical system designed at Vanderbilt University, Nashville, TN, as part of a collaborative effort among the Departments of Neurological Surgery, Computer Science,

Introduction The ever expanding gamut of medical imaging techniques provides the clinician an increasingly multifaceted view of brain function and anatomy. The information provided by the various imaging modalities is often complementary (i.e. provides separate but useful information) and synergistic (i.e. the combination of information provides useful extra information). For example, X-ray computed tomography (CT) and magnetic resonance (MR) imaging exquisitely demonstrate brain anatomy but provide little functional information. Positron emission tomography (PET) and single photon emission computed tomography (SPECT) scans display aspects of brain function and allow metabolic measurements but poorly delineate anatomy. Furthermore, CT and MR images describe complementary morphologic features. For example, bone and calcifications are best seen on CT images, while soft-tissue structures are better differentiated by MR imaging. Clinical diagnosis and therapy planning and evaluatio

This paper is an attempt to review the state-of-the-art cortical segmentation techniques in 2-D and 3-D using brain magnetic resonance imaging (MRI), their applications and new challenges

Abstract. We present a scale-invariant registration method for 3D structures reconstructed from a monocular endoscopic camera to pre-operative CT-scans. The presented approach is based on a previously presented method [2] for reconstruction of a scaled 3D model of the environment from unknown camera motion. We use this scaleless reconstruction as input to a PCA-based algorithm that recovers the scale and pose parameters of the camera in the coordinate frame of the CT scan. The result is used in an ICP registration method to refine the registration estimates. The presented approach is used for localization during sinus surgeries. It simplifies the navigation of the instrument by localizing it relative to the CT scan that was used for pre-operative procedure planning. The details of our approach and the experimental results with a phantom of a human skull are presented in this paper. 1

The growing demand for complex and minimally invasive surgical interventions is driving the search for ways to use computer-based information technology as a link between the pre-operative plan and the tools utilized by the surgeon. Computers, used in conjunction with advanced surgical assist devices, will fundamentally alter the way that are procedures are carried out in 21st Century operating rooms.

Abstract. This paper present a novel image-guided system for precise automatic targeting in keyhole minimally invasive neurosurgery. The system consists of a miniature robot fitted with a mechanical guide for needle/probe insertion. Intraoperatively, the robot is directly affixed to a head clamp or to the patient skull. It automatically positions itself with respect to predefined targets in a preoperative CT/MRI image following an anatomical registration with a intraoperative 3D surface scan of the patient facial features. We describe the preoperative planning and registration modules, and an in-vitro registration experiment of the entire system which yields a target registration error of 1.7mm (std=0.7mm). 1

Today’s neurosurgical journals are replete with advertisements for systems designed to provide image guidance during surgery. These so-called “frameless ” stereotactic systems provide the surgeon with navigational information, relating the location of instruments in the operative field to preoperative imaging data. Such information minimizes invasiveness by more accurately selecting the best trajectory to the lesion, ensures more precise identification of normal structures, and guides complete removal of a lesion. To achieve these goals, all of these systems utilize the stereotactic principle of coregistration of the patient with an imaging study. This review will trace the development of image-guided surgery from its origins in frame-based stereotaxy to its current use as a surgical navigation methodology. A review of the more prevalent techniques and available systems will be presented, along with examples of specific applications of surgical navigation. Finally, some of the future directions of frameless stereotaxy will be discussed. Key Words: Computer-assisted surgery, image-guided surgery, stereotaxy. Historical Background EARLY STEREOTACTIC SYSTEMS used a frame to satisfy the need for accurate co-registration and probe guidance. By fixing a frame to the head, Horsley and Clarke (1) were able to define a coordinate system in space that effectively included the intracranial contents. This defined space could then be related to a known atlas of the brain, and a probe could be directed to a specific site within the defined space. This proved to be a useful laboratory technique, but did not take into account normal anatomic variation. It was not immediately extended to clinical practice. Co-registration of frame-defined space with an individual imaging study followed. With the

Abstract — Despite rapid developments in the research areas medical imaging, medical image processing and robotics, the use of computer assistance in surgical routine is still limited to diagnostics, surgical planning, and interventions on mostly rigid structures. In order to establish a computer aided workflow from diagnosis to surgical treatment and follow-up, several proposals for computer assisted soft tissue interventions have been made in recent years. By means of different pre- and intraoperative information sources, like surgical plannings, intraoperative imaging, and tracking devices, surgical navigation systems aim at supporting surgeons in localizing anatomical targets, observing critical structures, and sparing healthy tissue. Current research in particular addresses the problem of organ shift and tissue deformation, and obstacles in communication between navigation system and surgeon. In this article, we review computer assisted navigation systems for soft tissue surgery. We concentrate on approaches which can be applied in endoscopic thoracic and abdominal surgery, as endoscopic surgery has special needs for image guidance due to limitations in perception. Furthermore, this article provides the reader with new trends and technologies in the area of computer assisted surgery. Finally, a balancing of key challenges and possible benefits of endoscopic navigation refines the perspectives of this increasingly important discipline of computer aided medical procedures. I.

A manually operated, electromechanically actuated neurosurgical probe-guide capable of sensing probe-tip force has been designed and built. Three methods of displaying the probe-tip force have been investigated: audio, visual and tactile. The audio feedback sounds an alarm when the force goes above the acceptable threshold. The visual display provides information about the alarm status and force magnitude. The tactile display uses a small tactor to translate force information into touch. The differences between the methods were tested in a series of experiments involving seven subjects operating the neurosurgical probe-guide while relying on one of the methods of feedback. Results show that visual feedback is better than audio or tactile feedback; mainly due to the extra information that visual feedback is able to provide.

ince 1985, a team of computer scien-S tists, mathematicians, physicians, and surgeons has been involved in a project at Grenoble Hospital called computer assisted medical interventions (CAMI). The aim of the project is to help surgeons and physicians use multimodal data in a rational and quantitative way in order to plan and to perform medical interventions. Recent advances in medical imaging systems such as CT and MRI have stimulated research on the interpretation of medical images. Nevertheless, very few systems allow for an efficient therapeutic use of the wealth of information these images contain,