54 resultados para fictionality-reality
Resumo:
CONTEXT: Compared with bare metal stents, sirolimus-eluting and paclitaxel-eluting stents have been shown to markedly improve angiographic and clinical outcomes after percutaneous coronary revascularization, but their performance in the treatment of de novo coronary lesions has not been compared in a prospective multicenter study. OBJECTIVE: To compare the safety and efficacy of sirolimus-eluting vs paclitaxel-eluting coronary stents. DESIGN: Prospective, randomized comparative trial (the REALITY trial) conducted between August 2003 and February 2004, with angiographic follow-up at 8 months and clinical follow-up at 12 months. SETTING: Ninety hospitals in Europe, Latin America, and Asia. PATIENTS: A total of 1386 patients (mean age, 62.6 years; 73.1% men; 28.0% with diabetes) with angina pectoris and 1 or 2 de novo lesions (2.25-3.00 mm in diameter) in native coronary arteries. INTERVENTION: Patients were randomly assigned in a 1:1 ratio to receive a sirolimus-eluting stent (n = 701) or a paclitaxel-eluting stent (n = 685). MAIN OUTCOME MEASURES: The primary end point was in-lesion binary restenosis (presence of a more than 50% luminal-diameter stenosis) at 8 months. Secondary end points included 1-year rates of target lesion and vessel revascularization and a composite end point of cardiac death, Q-wave or non-Q-wave myocardial infarction, coronary artery bypass graft surgery, or repeat target lesion revascularization. RESULTS: In-lesion binary restenosis at 8 months occurred in 86 patients (9.6%) with a sirolimus-eluting stent vs 95 (11.1%) with a paclitaxel-eluting stent (relative risk [RR], 0.84; 95% confidence interval [CI], 0.61-1.17; P = .31). For sirolimus- vs paclitaxel-eluting stents, respectively, the mean (SD) in-stent late loss was 0.09 (0.43) mm vs 0.31 (0.44) mm (difference, -0.22 mm; 95% CI, -0.26 to -0.18 mm; P<.001), mean (SD) in-stent diameter stenosis was 23.1% (16.6%) vs 26.7% (15.8%) (difference, -3.60%; 95% CI, -5.12% to -2.08%; P<.001), and the number of major adverse cardiac events at 1 year was 73 (10.7%) vs 76 (11.4%) (RR, 0.94; 95% CI, 0.69-1.27; P = .73). CONCLUSION: In this trial comparing sirolimus- and paclitaxel-eluting coronary stents, there were no differences in the rates of binary restenosis or major adverse cardiac events. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00235092.
Resumo:
Image-guided, computer-assisted neurosurgery has emerged to improve localization and targeting, to provide a better anatomic definition of the surgical field, and to decrease invasiveness. Usually, in image-guided surgery, a computer displays the surgical field in a CT/MR environment, using axial, coronal or sagittal views, or even a 3D representation of the patient. Such a system forces the surgeon to look away from the surgical scene to the computer screen. Moreover, this kind of information, being pre-operative imaging, can not be modified during the operation, so it remains valid for guidance in the first stage of the surgical procedure, and mainly for rigid structures like bones. In order to solve the two constraints mentioned before, we are developing an ultrasoundguided surgical microscope. Such a system takes the advantage that surgical microscopy and ultrasound systems are already used in neurosurgery, so it does not add more complexity to the surgical procedure. We have integrated an optical tracking device in the microscope and an augmented reality overlay system with which we avoid the need to look away from the scene, providing correctly aligned surgical images with sub-millimeter accuracy. In addition to the standard CT and 3D views, we are able to track an ultrasound probe, and using a previous calibration and registration of the imaging, the image obtained is correctly projected to the overlay system, so the surgeon can always localize the target and verify the effects of the intervention. Several tests of the system have been already performed to evaluate the accuracy, and clinical experiments are currently in progress in order to validate the clinical usefulness of the system.
Resumo:
PURPOSE: The aim of this study is to implement augmented reality in real-time image-guided interstitial brachytherapy to allow an intuitive real-time intraoperative orientation. METHODS AND MATERIALS: The developed system consists of a common video projector, two high-resolution charge coupled device cameras, and an off-the-shelf notebook. The projector was used as a scanning device by projecting coded-light patterns to register the patient and superimpose the operating field with planning data and additional information in arbitrary colors. Subsequent movements of the nonfixed patient were detected by means of stereoscopically tracking passive markers attached to the patient. RESULTS: In a first clinical study, we evaluated the whole process chain from image acquisition to data projection and determined overall accuracy with 10 patients undergoing implantation. The described method enabled the surgeon to visualize planning data on top of any preoperatively segmented and triangulated surface (skin) with direct line of sight during the operation. Furthermore, the tracking system allowed dynamic adjustment of the data to the patient's current position and therefore eliminated the need for rigid fixation. Because of soft-part displacement, we obtained an average deviation of 1.1 mm by moving the patient, whereas changing the projector's position resulted in an average deviation of 0.9 mm. Mean deviation of all needles of an implant was 1.4 mm (range, 0.3-2.7 mm). CONCLUSIONS: The developed low-cost augmented-reality system proved to be accurate and feasible in interstitial brachytherapy. The system meets clinical demands and enables intuitive real-time intraoperative orientation and monitoring of needle implantation.
Resumo:
During endoscopic surgery, it is difficult to ascertain the anatomical landmarks once the anatomy is fiddled with or if the operating area is filled with blood. An augmented reality system will enhance the endoscopic view and further enable surgeons to view hidden critical structures or the results of preoperative planning.
Resumo:
Three-dimensional (3D) ultrasound volume acquisition, analysis and display of fetal structures have enhanced their visualization and greatly improved the general understanding of their anatomy and pathology. The dynamic display of volume data generally depends on proprietary software, usually supplied with the ultrasound system, and on the operator's ability to maneuver the dataset digitally. We have used relatively simple tools and an established storage, display and manipulation format to generate non-linear virtual reality object movies of prenatal images (including moving sequences and 3D-rendered views) that can be navigated easily and interactively on any current computer. This approach permits a viewing or learning experience that is superior to watching a linear movie passively.
Resumo:
Spontaneous confabulation is a rare memory disorder resulting from orbitofrontal damage or disconnection. Patients act on the basis of memories that do not pertain to the current situation, and are disoriented. No medical treatment is known. Recent studies suggest that subcortical dopaminergic structures are involved in the selection of currently relevant memories. We present a patient who regained the ability to adapt thought and behavior to ongoing reality when treated with risperidone, a dopamine antagonist.