WxBS: Wide Baseline Stereo Generalizations

We have presented a new problem -- the wide multiple baseline stereo (WxBS) -- which considers matching of images that simultaneously differ in more than one image acquisition factor such as viewpoint, illumination, sensor type or where object appearance changes significantly, e.g. over time. A new dataset with the ground truth for evaluation of matching algorithms has been introduced and will be made public. We have extensively tested a large set of popular and recent detectors and descriptors and show than the combination of RootSIFT and HalfRootSIFT as descriptors with MSER and Hessian-Affine detectors works best for many different nuisance factors. We show that simple adaptive thresholding improves Hessian-Affine, DoG, MSER (and possibly other) detectors and allows to use them on infrared and low contrast images. A novel matching algorithm for addressing the WxBS problem has been introduced. We have shown experimentally that the WxBS-M matcher dominantes the state-of-the-art methods both on both the new and existing datasets.Comment: Descriptor and detector evaluation expande

Automatic 3D Reconstruction of Coronary Artery Centerlines from Monoplane X-ray Angiogram Images

We present a new method for the fully automatic 3D reconstruction of the coronary artery centerlines, using two X-ray angiogram projection images from a single rotating monoplane acquisition system. During the first stage, the input images are smoothed using curve evolution techniques. Next, a simple yet efficient multiscale method, based on the information of the Hessian matrix, for the enhancement of the vascular structure is introduced. Hysteresis thresholding using different image quantiles, is used to threshold the arteries. This stage is followed by a thinning procedure to extract the centerlines. The resulting skeleton image is then pruned using morphological and pattern recognition techniques to remove non-vessel like structures. Finally, edge-based stereo correspondence is solved using a parallel evolutionary optimization method based on f symbiosis. The detected 2D centerlines combined with disparity map information allow the reconstruction of the 3D vessel centerlines. The proposed method has been evaluated on patient data sets for evaluation purposes

Racial Differences in the Distribution of Posterior Circulation Occlusive Disease

We Compared Clinical and Arteriographic Features in 27 White and 24 Black Patients with Symptomatic Posterior Circulation Occlusive Disease. the Degree of Arterial Stenosis Was Measured Independently by Two Examiners at 12 Sites within the Vertebrobasilar Territory. Racial Comparisons Were Made based Upon the Distribution of Extra- and Intracranial Occlusive Lesions and Symptomatic Sites of the Lesions. White Patients Had Significantly More Angina Pectoris, More Lesions of the Origin of the Left Vertebral Artery and More High-Grade Lesions of the Extracranial Vertebral Arteries. Black Patients Had Significantly Higher Mean Diastolic Blood Pressure, More Diabetes Mellitus, More Lesions of the Distal Basilar Artery, More High-Grade Lesions of Intracranial Branch Vessels and More Symptomatic Intracranial Branch Disease. Race Was Found to Be the Only Factor Increasing the Risk of Intracranial Posterior Circulation Occlusive Disease. Knowledge of the Contribution of Race to the Distribution of Posterior Circulation Lesions Will Help Guide Evaluation and Treatment Strategies for Patients with Vertebrobasilar Occlusive Disease. © 1985 American Heart Association, Inc

Impact of smoking status on outcome in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention

There are some data showing lower mortality of smokers comparing to non-smokers in patients with ST-segment elevation myocardial infarction (STEMI) when treated with thrombolysis or without reperfusion therapy. However, the role of smoking status is less established in patients with STEMI undergoing mechanical reperfusion. We evaluate the influence of smoking on outcome in patients with STEMI treated with primary percutaneous coronary intervention (PCI). A total of 1,086 patients enrolled into EUROTRANSFER Registry were included into present analysis. Patients were divided according to smoking status during STEMI presentation into those who were current smokers (391 patients, 36 %) and non-smokers (695 patients, 64 %). Current smokers were younger and more often men and less frequently had high-risk features as previous myocardial infarction, history of chronic renal failure, previous PCI, diabetes mellitus, anterior wall STEMI, and multivessel disease. Unadjusted mortality at 1 year was lower in current smokers comparing to non-smokers (3.3 vs. 9.5 %; OR 0.33 CI 0.18–0.6; p = 0.0001). However, after adjustment for age and gender by logistic regression, there was no longer significant difference between groups (OR 0.7; CI 0.37–1.36; p = 0.30). In conclusion, current smokers with STEMI treated with primary PCI have lower mortality at 1 year comparing to non-smokers, but this result may be explained by differences in baseline characteristics and not by smoking status itself. Current smokers developed STEMI more than 10 years earlier than non-smokers with similar age and sex-adjusted risk of death at 1 year. These results emphasize the role of efforts to encourage smoking cessation as prevention of myocardial infarction

The sheep as a pre-clinical model for testing intra-aortic percutaneous mechanical circulatory support devices

The save deployment of intra-aortic percutaneous mechanical circulatory support devices is highly dependent on the inner aortic diameter. Finding the anatomically and ethically most suitable animal model for performance testing of new pMCS devices remains challenging. For this study, an ovine model using adult ewes of a large framed breed (Swiss White Alpine Sheep) was developed to test safety, reliability, and biocompatibility of catheter-mounted mechanical support devices placed in the descending thoracic aorta. Following the drawback of fluctuating aortic diameter and device malfunction in the first four animals, the model was improved by stenting the following animals with an aortic stent. Stenting the animals with an intra-aortic over the balloon stent was found to standardize the experimental set-up and to avoid early termination of the experiment due to non-device related issues. Keywords: 3R; Mechanical circulatory support; animal model; preclinical study; sheep; thoracic aort