Intelligent Operating Theater Using Intraoperative Open-MRI
Faculty of Advanced Technosurgery, Division of Advanced Biomedical Engineering & Science, Graduate School of Medicine, Institute of Advanced Biomedical Engineering & Science, Tokyo Women's Medical University, Japan. Magnetic Resonance in Medical Sciences
(Impact Factor: 1.48).
02/2005; 4(3):129-36. DOI: 10.2463/mrms.4.129
Malignant brain tumors vary among patients and are characterized by their irregular shapes and infiltration. Localization of functional areas in the brain also differs among patients, and excess removal of tumor near eloquent areas may increase the risk of damage of function, such as motor paresis and speech disturbance. Recent progress in magnetic resonance (MR) imaging technology has enabled acquisition of intraoperative images and totally changed the neurosurgery of malignant brain tumors. Before, surgeons could merely speculate about the results of surgical manipulation and have no certainty about procedure outcomes until postoperative examination. Because intraoperative MR images allow visualization of the size of residual tumor(s) and the positional relationship between the tumor(s) and eloquent areas, surgeons are now able to achieve safe and reliable surgery. As an example, positional error on preoperative MR images caused by shifting of the brain (brain shift), a long-standing annoyance for surgeons, has been resolved using intraoperative MR images for surgical navigation, allowing precise resection. Two types of open-MR imaging scanner, a 0.2- or 0.3-tesla hamburger-type scanner with a horizontal gap and a 0.12- or 0.5-tesla double doughnut-type scanner with a vertical gap, are now available in the operating theater, and 1.5-tesla bore-type scanners are available. A 3.0-tesla bore-type scanner is planned. Intraoperative MR imaging includes diffusion-tensor and diffusion-weighted imaging, which allows visualization of nerve fibers in the white matter, especially the pyramidal tract. Such images are valuable aids in the precise resection of residual lesions of malignant brain tumors near eloquent areas without injuring motor function.
Available from: Takashi Suzuki
- "The MRI system uses a permanent magnet to generate a vertical static magnetic field, whose strength is 0.3 T . A lower magnetic field has various merits. "
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ABSTRACT: This paper introduces an intelligent operating theater equipped with a magnetic resonance imaging (MRI) scanner and video recording and broadcasting system to enhance the quality of surgery. To reduce error, intraoperative incidents are detected and dealt with using semi-automatic computer algorithm. A multiple-channel video recording and broadcasting system was installed in an operating room and the surgical procedure was recorded. The supervising surgeon monitored the operation in real-time from outside the operating room. Information sharing via the intra-hospital network improved the work efficiency of staff. The amount of motion was estimated from recorded file size based on the principle of inter-frame video compression. A time period for which the file size significantly increased compared to those for neighboring time periods was chosen and the majority voting technique was applied to detect events using six channels of the video. A change in file size indicated a phase change of the surgical procedure. The proposed method is promising for future daily clinical procedure.
Available from: Takashi Suzuki
- "Since then, such devices have been used for real-time observation of surgical manipulations, for assessment of the extent of tumor resection, and evaluation of the intraoperative complications. While real-time guidance of the surgical manipulations with iMRI is theoretically presumed to be the most effective, such systems usually provide relatively narrow working space and necessitate all surgical devices to be composed of non-ferromagnetic materials (Iseki et al., 2005). By contrast, if iMRI investigations are performed at some temporary break points during surgical procedure, it can provide a higher degree of freedom for the surgeon and permit to use standard (not MRI-compatible) neurosurgical instrumentarium. "
Available from: terpconnect.umd.edu
- "Intraoperative MRI supplements the surgeon's visual and tactile senses in a way that no other imaging device can achieve. In many ways, intraoperative MRI has revolutionized the ability of the neurosurgeon to obtain complete tumor resection without jeopardizing normal tissues      with early evidence suggesting that its use is associated with improved survival . Other imaging modalities such as computed tomography (CT) and ultrasound (US) are not feasible since CT leads to radiation exposure and not as good image quality compared to MRI . "
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ABSTRACT: Brain tumors are among the most feared complications of cancer and they occur in 20-40% of adult cancer patients. Despite numerous advances in treatment, the prognosis for these patients is poor, with a median survival of 4-8 months. The primary reasons for poor survival rate are the lack of good continuous imaging modality for intraoperative intracranial procedures and the inability to remove the complete tumor tissue due to its placement in the brain and the corresponding space constraints to reach it. Intraoperative magnetic resonance imaging (MRI) supplements the surgeon's visual and tactile senses in a way that no other imaging device can achieve resulting in less trauma to surrounding healthy brain tissue during surgery. To minimize the trauma to surrounding healthy brain tissue, it would be beneficial to operate through a narrow surgical corridor dissected by the neurosurgeon. Facilitating tumor removal by accessing regions outside the direct "line-of- sight" of the neurosurgical corridor will require a highly dexterous, small cross section, and MRI-compatible robot. Developing such a robot is extremely challenging task. In this paper we report a preliminary design of 6-DOF robot for possible application in neurosurgery. The robot actuators and body parts are constructed from MRI compatible materials. The current prototype is 0.36" in diameter and weighs only 0.0289 N (2.95 grams). The device was actuated using Flexinol® which is a shape memory alloy manufactured by Dynalloy, Inc. The end-effector forces ranged from 12 mN to 50 mN depending on the robot configuration. The end-effector force to robot weight ratio varied from 0.41 to 1.73. During trials the robot motion was repeatable and the range of motion of the robot was about 90 degrees for the end-effector when one side shape memory alloy (SMA) channel was actuated. The actuation time from the start to finish was about 2.5 s.
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