Nobuhiko Hata

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A surgical guidance and visualization system is presented, which uniquely integrates capabilities for data analysis and on-line interventional guidance into the setting of interventional MRI. Various pre-operative scans (T1- and T2-weighted MRI, MR angiography, and functional MRI (fMRI)) are fused and automatically aligned with the operating field of the(More)
We present a software package which uniquely integrates several facets of image-guided medicine into a single portable, extendable environment. It provides capabilities for automatic registration, semiautomatic segmentation, 3D surface model generation, 3D visualization, and quantitative analysis of various medical scans. We describe its system(More)
In this report we evaluate an image registration technique that can improve the information content of intraoperative image data by deformable matching of preoperative images. In this study, pretreatment 1.5 tesla (T) magnetic resonance (MR) images of the prostate are registered with 0.5 T intraoperative images. The method involves rigid and nonrigid(More)
OBJECTIVE A major shortcoming of image-guided navigational systems is the use of preoperatively acquired image data, which does not account for intraoperative changes in brain morphology. The occurrence of these surgically induced volumetric deformations ("brain shift") has been well established. Maximal measurements for surface and midline shifts have been(More)
Magnetic resonance imaging (MRI) can provide high-quality 3-D visualization of prostate and surrounding tissue, thus granting potential to be a superior medical imaging modality for guiding and monitoring prostatic interventions. However, the benefits cannot be readily harnessed for interventional procedures due to difficulties that surround the use of(More)
BACKGROUND With increasing research on system integration for image-guided therapy (IGT), there has been a strong demand for standardized communication among devices and software to share data such as target positions, images and device status. METHOD We propose a new, open, simple and extensible network communication protocol for IGT, named OpenIGTLink,(More)
A magnetic resonance (MR) compatible surgical assistance robot system, designed to aid minimally invasive surgical techniques, such as positioning and directing a catheter or a laser pointer, has been built and is under preclinical evaluation. Two specific issues arise in the MR environment: (i) the reduced space in which to place the robot; and (ii) the MR(More)
A magnetic resonance (MR) compatible surgical assist robot system under preclinical evaluation is described. It is designed to coexist, and cooperate, with a surgeon, and to position and direct an axisymmetric tool, such as a laser pointer or a biopsy catheter. The main mechanical body is located above the head of the surgeon, and two rigid arms extend to(More)
A real-time ultrasound-guided needle-insertion medical robot for percutaneous cholecystostomy has been developed. Image-guided interventions have become widely accepted because they are consistent with minimal invasiveness. However, organ or abnormality displacement due to involuntary patient motion may undesirably affect the intervention. The proposed(More)
OBJECTIVE We have developed a frameless stereotactic neuronavigation system that allows navigation during neurosurgical procedures through an image formed from integrating ultrasonography and preoperative magnetic resonance (MR) imaging and/or x-ray computed tomography. METHODS The system consists of a ultrasound imaging scanner, a workstation with an(More)