@article{SzeStrobelFahrigetal., author = {Sze, Daniel Y. and Strobel, Norbert and Fahrig, Rebecca and Moore, Teri and Busque, Stephan and Frisoli, Joan K.}, title = {Transjugular intrahepatic portosystemic shunt creation in a polycystic liver facilitated by hybrid cross-sectional/angiographic imaging}, series = {Journal of Vascular and Interventional Radiology (JVIR)}, volume = {17}, journal = {Journal of Vascular and Interventional Radiology (JVIR)}, number = {4}, doi = {10.1097/01.rvi.0000208984.17697.58}, pages = {711 -- 715}, abstract = {Polycystic liver disease (PCLD) has long been considered to represent a contraindication to transjugular intrahepatic portosystemic shunt (TIPS) creation, primarily because of the risk of hemorrhage. Three-dimensional (3D) navigation within the enlarged and potentially disorienting parenchyma can now be performed during the procedure with the development of C-arm cone-beam computed tomography, which relies on the same equipment already used for angiography. Such a hybrid 3D reconstruction-enabled angiography system was used for safe image guidance of a TIPS procedure in a patient with PCLD. This technology has the potential to expedite any image-guided procedure that requires 3D navigation.}, language = {en} } @article{StrobelSporsRabenstein, author = {Strobel, Norbert and Spors, Sascha and Rabenstein, Rudolf}, title = {Joint audio-video object localization and tracking}, series = {IEEE Signal Processing Magazine}, volume = {18}, journal = {IEEE Signal Processing Magazine}, number = {1}, publisher = {IEEE}, doi = {10.1109/79.911196}, pages = {22 -- 31}, abstract = {There has been a tremendous amount of research on object localization either involving microphone arrays or video cameras. Considerable less attention has been paid, however, to object localization and tracking based on joint audio-video processing thus far. This may be related to the lack of suitable algorithms for object localization simultaneously using multimicrophone outputs and color image sequences. In this article, we propose a solution to this problem. Before elaborating on joint audio-video processing, we review some previous work the areas of audio and video object localization. Then a recursive sensor fusion method based on decentralized Kalman filtering is introduced. Unfortunately, the decentralized Kalman filter cannot be directly used for joint audio-video object localization due to specific properties of the audio sensor. By properly adjusting the local audio position estimator, however, we manage to keep the overall architecture. We stress the general methodology.}, language = {en} } @article{RamponiStrobelMitraetal., author = {Ramponi, Giovanni and Strobel, Norbert and Mitra, Sanjit K. and Yu, Tian-Hu}, title = {Nonlinear unsharp masking methods for image contrast enhancement}, series = {Journal of Electronic Imaging}, volume = {5}, journal = {Journal of Electronic Imaging}, number = {3}, doi = {10.1117/12.242618}, pages = {353 -- 366}, abstract = {In the unsharp masking approach for image enhancement, a fraction of the highpass filtered version of the image is added to the original image to form the enhanced version. The method is simple, but it suffers from two serious drawbacks. First, it enhances the contrast in the darker areas perceptually much more strongly than that in the lighter areas. Second, it enhances the noise and/or digitization effects, particularly in the darker regions, resulting in visually less pleasing enhanced images. In general, noise can be suppressed with lowpass filters, which are associated with the blurring of the edges. On the other hand, contrast can be enhanced with highpass filters, which are associated with noise amplification. A reasonable solution, therefore, is to use suitable nonlinear filters which combine the features of both highpass and lowpass filters. This paper outlines several new methods of unsharp masking based on the use of such nonlinear filters. Computer simulations have verified the superior results obtained using these filters. In addition, a new measure of contrast enhancement is introduced which quantitatively supports the improvement obtained using the proposed methods.}, language = {en} } @inproceedings{BourierSchneiderGanslmeieretal., author = {Bourier, F. and Schneider, H.-J. and Ganslmeier, F. and Heißenhuber, F. and Fischer, R. and Brost, A. and Koch, M. and Strobel, Norbert and Hornegger, J. and Kurzidim, K.}, title = {Unterst{\"u}tzung der transseptalen Punktion durch vorherige {\"U}berlagerung eines 3D-Volumens von linkem Atrium und Aorta}, series = {77. Jahrestagung Fr{\"u}hjahrestagung der Gesellschaft f{\"u}r Kardiologie Mannheim 27.04. - 30.04.2011}, booktitle = {77. Jahrestagung Fr{\"u}hjahrestagung der Gesellschaft f{\"u}r Kardiologie Mannheim 27.04. - 30.04.2011}, language = {de} } @inproceedings{KochLangenkampKiralyetal., author = {Koch, M. and Langenkamp, A. and Kiraly, A. and Brost, A. and Strobel, Norbert and Hornegger, J.}, title = {Navigation System with Contact Force Assessment to Guide Pulmonary Vein Isolation Procedures}, series = {23rd Conference of the Society for Medical Innovation and Technology (SMIT) Tel Aviv 01/2011}, booktitle = {23rd Conference of the Society for Medical Innovation and Technology (SMIT) Tel Aviv 01/2011}, language = {en} } @inproceedings{BourierBrostKleinoederetal., author = {Bourier, F. and Brost, A. and Kleinoeder, A. and Schneider, H.-J. and Heißenhuber, F. and Ganslmeier, P. and Raab, J. and Koch, M. and Hornegger, J. and Strobel, Norbert and Kurzidim, K.}, title = {3D-Visualisation of Cryo-Balloon Ablation Catheters to Evaluate Left Atrial Anatomy for PVI}, series = {Venice Arrhythmias 01/2011}, booktitle = {Venice Arrhythmias 01/2011}, language = {en} } @inproceedings{BourierSchneiderHeissenhuberetal., author = {Bourier, F. and Schneider, H.-J. and Heißenhuber, F. and Ganslmeier, P. and Brost, A. and Koch, M. and Hornegger, J. and Kleinoeder, A. and Kiraly, A. and Barbot, J. and Strobel, Norbert and Kurzidim, K.}, title = {Augmented Fluoroscopy to Guide Transseptal Puncture}, series = {Venice Arrhythmias 2011 01/2011}, booktitle = {Venice Arrhythmias 2011 01/2011}, language = {en} } @inproceedings{BourierSchneiderHeissenhuberetal., author = {Bourier, F. and Schneider, H.-J. and Heißenhuber, F. and Ganslmeier, P. and Brost, A. and Koch, M. and Hornegger, J. and Kleinoeder, A. and Kiraly, A. and Barbot, J. and Strobel, Norbert and Kurzidim, K.}, title = {Pulmonary Vein Isolation guided by fluoroscopybased 3D-Navigation on a biplane angiography system}, series = {Venice Arrhythmias 2011 01/2011}, booktitle = {Venice Arrhythmias 2011 01/2011}, language = {en} } @inproceedings{BrostWimmerLiaoetal., author = {Brost, A. and Wimmer, A. and Liao, R. and Hornegger, J. and Strobel, Norbert}, title = {Catheter Tracking: Filter-Based vs. Learning-Based}, series = {M. Goesele, S. Roth, A. Kuijper, B. Schiele, K. Schindler (eds.) Pattern Recognintion, LNCS, vol. 6376}, booktitle = {M. Goesele, S. Roth, A. Kuijper, B. Schiele, K. Schindler (eds.) Pattern Recognintion, LNCS, vol. 6376}, publisher = {Springer}, address = {Berlin, Heidelberg}, isbn = {978-3-642-15985-5}, doi = {https://doi.org/10.1007/978-3-642-15986-2_30}, pages = {293 -- 302}, language = {en} } @incollection{HoffmannMuellerKurzidimetal., author = {Hoffmann, Matthias and M{\"u}ller, Simone and Kurzidim, Klaus and Strobel, Norbert and Hornegger, Joachim}, title = {Robust Identification of Contrasted Frames in Fluoroscopic Images}, series = {Bildverarbeitung f{\"u}r die Medizin 2015}, booktitle = {Bildverarbeitung f{\"u}r die Medizin 2015}, publisher = {Springer Vieweg}, address = {Berlin, Heidelberg}, isbn = {978-3-662-46223-2}, doi = {10.1007/978-3-662-46224-9_6}, abstract = {For automatic registration of 3-D models of the left atrium to fluoroscopic images, a reliable classification of images containing contrast agent is necessary. Inspired by previous approaches on contrast agent detection, we propose a learning-based framework which is able to classify contrasted frames more robustly than previous methods, Furthermore, we performed a quantitative evaluation on a clinical data set consisting of 34 angiographies. Our learning-based approach reached a classification rate of 79.5\%. The beginning of a contrast injection was detected correctly in 79.4\%.}, language = {en} } @inproceedings{HohlBoeseStrobeletal., author = {Hohl, C. and Boese, Jan and Strobel, Norbert and Banckwitz, R. and Lauritsch, G. and M{\"u}hlenbruch, G. and G{\"u}nther, R. W.}, title = {Angiographische CT: Messung der Patientendosis}, series = {R{\"o}Fo: Fortschritte auf dem Gebiet R{\"o}ntgenstrahlen und bildgebenden Verfahren}, volume = {180}, booktitle = {R{\"o}Fo: Fortschritte auf dem Gebiet R{\"o}ntgenstrahlen und bildgebenden Verfahren}, number = {S 1}, doi = {10.1055/s-2008-1073628}, abstract = {Ziele: Messung der Organ- und Effektivdosen bei Angiographischen CT-Untersuchungen (ACT) des Kopfs, des Herzens, der Leber sowie der Lendenwirbels{\"a}ule (LWS) mit einem anthropomorphen Phantom und Thermolumineszenz Dosimetern (TLD). Methode: ACT erlaubt die Schnittbildgebung von Weichteilstrukturen bei der Verwendung einer C-Bogen Durchleuchtungseinheit mit Flachbilddetektor. Um die sowohl die Organdosen als auch die effektiven Dosen bei ACT-Untersuchungen des Kopfs, des Herzens, der Leber und der LWS zu bestimmen, wurde ein m{\"a}nnliches Alderson-Rando-Phantom mit jeweils 129 TLD an 43 Messstellen best{\"u}ckt. Die Messungen wurden an zwei ACT-Systemen (AXIOM Artis, VB31C, Siemens, Forchheim) mit verschiedenen Detektorgr{\"o}ßen (20×20cm und 30×40cm) durchgef{\"u}hrt. Mit dem 20×20 Detektor wurden der Kopf (70kV, 126 frames, 0,36µGy/frame, 7,9ms/frame), die LWS (90kV, 275 frames, 0,36Gy/frame, 4,9ms/frame) und das Herz (70kV, 126 frames, 0,54µGy/frame, 10,9ms/frame) untersucht. Mit dem 30×40 Detektor wurden der Kopf (84kV, 496 frames, 1,2µGy/frame, 11,6ms/frame) die Leber (90kV, 397 frames, 0,36µGy/frame, 4,9ms/frame) und das Herz (70kV, 248 frames, 0,54µGy/frame, 4,9ms/frame) untersucht. Zus{\"a}tzlich wurde mit dem 30×40 Detektor noch eine EKG-getriggerte Herz-Untersuchung durchgef{\"u}hrt (992 frames, Phasen-Zentrum 75\%, Phasen-L{\"a}nge 50\%, 50\% mAs-Modulation). Nach jeder Messung wurden die TLD gewechselt und ausgewertet. Gem{\"a}ß den ICRP-Empfehlungen sind Organ- und Effektivdosen berechnet worden, die dann mit bekannten Dosiswerten vergleichbarer MSCT-Untersuchungen korreliert wurden. Ergebnis: Die Messungen der effektiven Dosis f{\"u}r den 20×20 Detektor ergaben Werte von 0,2mSv (Kopf), 2,76mSv (LWS) und 1,25mSv (Herz). Mit dem 30×40 Detektor ergaben sich Werte von 2,95mSv (Kopf), 6,71mSv (Leber) und 3,31mSv (Herz, 248 frames). F{\"u}r die EKG-getriggerte Untersuchung des Herzens ergab sich eine effektive Dosis von 10,88 mSv bei 4 Uml{\"a}ufen (992 frames). Vergleichbare MSCT-Untersuchung belaufen sich auf 2,9mSv (Kopf), 4,8mSv (LWS), 4,3mSv (Leber) und 8,3mSv (Herz). Schlussfolgerung: Da ACT-Systeme mit einer Belichtungsautomatik ausgestattet sind, h{\"a}ngt die effektive Dosis stark vom Patientendurchmesser ab. Bei Messungen mit dem anthropomorphen Phantom konnte gezeigt werden, dass die effektiven Dosen von ACT-Untersuchungen sogar noch unterhalb von vergleichbaren MSCT-Untersuchungen liegen k{\"o}nnen. Allerdings muss dabei ber{\"u}cksichtigt werden, dass die Bildqualit{\"a}t und insbesondere der Weichteilkontrast nicht vergleichbar sind.}, language = {de} }