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Auflistung nach Autor:in "Wesarg, Stefan"

1 - 3 von 3
  • Konferenzbeitrag
    Area preserving parameterisation of shapes with spherical topology
    (Informatik 2009 – Im Focus das Leben, 2009) Kirschner, Matthias; Wesarg, Stefan
  • Konferenzbeitrag
    An automated 4D approach for left ventricular assessment in clinical cine MR images
    (INFORMATIK 2006 – Informatik für Menschen, Band 1, 2006) Wesarg, Stefan; Nowak, Stefanie
    Cine Magnetic Resonance (MR) imaging has become the method-of-choice for the examination of the dynamic behaviour of the heart. An assessment of the left ventricle can reveal regions of myocardial dysfunction and their severeness. The scope of this work is a complete analysis of the left ventricular dynamics for the usage in a clinical environment. For that purpose, endocardial and epicardial borders are automatically extracted in 3D cine data in a first step. This is followed by a segmentation of the endocardium and the myocardium into 17 segments following the recommendations of the American Heart Association and the computation of common global volumetric values (stroke volume, ejection fraction etc.) and parameters that describe the left ventricular dynamics (wall motion, wall thickening). A retrospective analysis of cardiac cine MR image data from 20 patients (healthy ones, patients with abnormal wall motion, and patients who suffered an infarction) has been done. That image data has been acquired in the clinical routine at two different hospitals. The here presented automated approach led to a successful segmentation and assessment of the left ventricle for all data sets. The pathological cases could be identified easily due to their characteristic change of the motion pattern. The main advantage of our approach is the reproducibility of the assessment results and the gain in time for the cardiologist who has to analyse the huge amount of cine data.
  • Konferenzbeitrag
    Patient specific optimal catheter selection for the left coronary artery
    (INFORMATIK 2011 – Informatik schafft Communities, 2011) Rahman, Sami Ur; Wesarg, Stefan; Völker, Wolfram
    During coronary artery angiography, a catheter is used to inject a contrast dye into the coronary arteries. Due to the anatomical variation of the aorta and the coronary arteries in different humans, one common catheter cannot be used for all patients. The cardiologists test different catheters for a patient and select the best one according to the patient's anatomy. To overcome these problems, we propose a computer-aided catheter selection procedure. In this paper we present our approach for patient specific optimal catheter selection for the angiography of the left coronary artery (LCA). It involves segmentation of the aorta and coronary arteries, finding the centerline and computing some geometric parameters. These parameters include curve angle of the LCA, LCA contralateral wall curve length, and the aorta cavity length. We then consider catheters for the LCA and compute the angles and lengths of the two curves as well as the distance between these curves. We suggest a catheter that is the closest one to the patient's arteries geometry. This solution avoids testing of many catheters during catheterization. The cardiologist already gets a recommendation about the optimal catheter for the patient prior to the intervention.