@article{AugustinWolfschmidtElsaesseretal.2022, author = {Augustin, Anne Marie and Wolfschmidt, Franziska and Els{\"a}sser, Thilo and Sauer, Alexander and Dierks, Alexander and Bley, Thorsten Alexander and Kickuth, Ralph}, title = {Color-coded summation images for the evaluation of blood flow in endovascular aortic dissection fenestration}, series = {BMC Medical Imaging}, volume = {22}, journal = {BMC Medical Imaging}, number = {1}, doi = {10.1186/s12880-022-00744-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301107}, year = {2022}, abstract = {Background To analyze the benefit of color-coded summation images in the assessment of target lumen perfusion in patients with aortic dissection and malperfusion syndrome before and after fluoroscopy-guided aortic fenestration. Methods Between December 2011 and April 2020 25 patients with Stanford type A (n = 13) or type B dissection (n = 12) and malperfusion syndromes were treated with fluoroscopy-guided fenestration of the dissection flap using a re-entry catheter. The procedure was technically successful in 100\% of the cases and included additional iliofemoral stent implantation in four patients. Intraprocedural systolic blood pressure measurements for gradient evaluation were performed in 19 cases. Post-processed color-coded DSA images were obtained from all DSA series before and following fenestration. Differences in time to peak (dTTP) values in the compromised aortic lumen and transluminal systolic blood pressure gradients were analyzed retrospectively. Correlation analysis between dTTP and changes in blood pressure gradients was performed. Results Mean TTP prior to dissection flap fenestration was 6.85 ± 1.35 s. After fenestration, mean TTP decreased significantly to 4.96 ± 0.94 s (p < 0.001). Available systolic blood pressure gradients between the true and the false lumen were reduced by a median of 4.0 mmHg following fenestration (p = 0.031), with significant reductions in Stanford type B dissections (p = 0.013) and minor reductions in type A dissections (p = 0.530). A moderate correlation with no statistical significance was found between dTTP and the difference in systolic blood pressure (r = 0.226; p = 0.351). Conclusions Hemodynamic parameters obtained from color-coded DSA confirmed a significant reduction of TTP values in the aortic target lumen in terms of an improved perfusion in the compromised aortic region. Color-coded DSA might thus be a suitable complementary tool in the assessment of complex vascular patterns prevailing in aortic dissections, especially when blood pressure measurements are not conclusive or feasible.}, language = {en} } @article{WestermaierLinsenmannHomolaetal.2016, author = {Westermaier, Thomas and Linsenmann, Thomas and Homola, Gy{\"o}rgy A. and Loehr, Mario and Stetter, Christian and Willner, Nadine and Ernestus, Ralf-Ingo and Soymosi, Laszlo and Vince, Giles H.}, title = {3D rotational fluoroscopy for intraoperative clip control in patients with intracranial aneurysms - assessment of feasibility and image quality}, series = {BMC Medical Imaging}, volume = {16}, journal = {BMC Medical Imaging}, number = {30}, doi = {10.1186/s12880-016-0133-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146381}, year = {2016}, abstract = {Background Mobile 3D fluoroscopes have become increasingly available in neurosurgical operating rooms. In this series, the image quality and value of intraoperative 3D fluoroscopy with intravenous contrast agent for the evaluation of aneurysm occlusion and vessel patency after clip placement was assessed in patients who underwent surgery for intracranial aneurysms. Materials and methods Twelve patients were included in this retrospective analysis. Prior to surgery, a 360° rotational fluoroscopy scan was performed without contrast agent followed by another scan with 50 ml of intravenous iodine contrast agent. The image files of both scans were transferred to an Apple PowerMac® workstation, subtracted and reconstructed using OsiriX® free software. The procedure was repeated after clip placement. Both image sets were compared for assessment of aneurysm occlusion and vessel patency. Results Image acquisition and contrast administration caused no adverse effects. Image quality was sufficient to follow the patency of the vessels distal to the clip. Metal artifacts reduce the assessability of the immediate vicinity of the clip. Precise image subtraction and post-processing can reduce metal artifacts and make the clip-site assessable and depict larger neck-remnants. Conclusion This technique quickly supplies images at adequate quality to evaluate distal vessel patency after aneurysm clipping. Significant aneurysm remnants may be depicted as well. As it does not require visual control of all vessels that are supposed to be evaluated intraoperatively, this technique may be complementary to other intraoperative tools like indocyanine green videoangiography and micro-Doppler, especially for the assessment of larger aneurysms. At the momentary state of this technology, it cannot replace postoperative conventional angiography. However, 3D fluoroscopy and image post-processing are young technologies. Further technical developments are likely to result in improved image quality.}, language = {en} } @article{SchwitterWackerWilkeetal.2012, author = {Schwitter, Juerg and Wacker, Christian M. and Wilke, Norbert and Al-Saadi, Nidal and Sauer, Ekkehart and Huettle, Kalman and Sch{\"o}nberg, Stefan O. and Debl, Kurt and Strohm, Oliver and Ahlstrom, Hakan and Dill, Thorsten and Hoebel, Nadja and Simor, Tamas}, title = {Superior diagnostic performance of perfusion-cardiovascular magnetic resonance versus SPECT to detect coronary artery disease: The secondary endpoints of the multicenter multivendor MR-IMPACT II (Magnetic Resonance Imaging for Myocardial Perfusion Assessment in Coronary Artery Disease Trial)}, series = {Journal of Cardiovascular Magnetic Resonance}, volume = {14}, journal = {Journal of Cardiovascular Magnetic Resonance}, number = {61}, organization = {MR-IMPACT investigators}, doi = {10.1186/1532-429X-14-61}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134256}, year = {2012}, abstract = {Background: Perfusion-cardiovascular magnetic resonance (CMR) is generally accepted as an alternative to SPECT to assess myocardial ischemia non-invasively. However its performance vs gated-SPECT and in sub-populations is not fully established. The goal was to compare in a multicenter setting the diagnostic performance of perfusion-CMR and gated-SPECT for the detection of CAD in various populations using conventional x-ray coronary angiography (CXA) as the standard of reference. Methods: In 33 centers (in US and Europe) 533 patients, eligible for CXA or SPECT, were enrolled in this multivendor trial. SPECT and CXA were performed within 4 weeks before or after CMR in all patients. Prevalence of CAD in the sample was 49\% and 515 patients received MR contrast medium. Drop-out rates for CMR and SPECT were 5.6\% and 3.7\%, respectively (ns). The study was powered for the primary endpoint of non-inferiority of CMR vs SPECT for both, sensitivity and specificity for the detection of CAD (using a single-threshold reading), the results for the primary endpoint were reported elsewhere. In this article secondary endpoints are presented, i.e. the diagnostic performance of CMR versus SPECT in subpopulations such as multi-vessel disease (MVD), in men, in women, and in patients without prior myocardial infarction (MI). For diagnostic performance assessment the area under the receiver-operator-characteristics-curve (AUC) was calculated. Readers were blinded versus clinical data, CXA, and imaging results. Results: The diagnostic performance (= area under ROC = AUC) of CMR was superior to SPECT (p = 0.0004, n = 425) and to gated-SPECT (p = 0.018, n = 253). CMR performed better than SPECT in MVD (p = 0.003 vs all SPECT, p = 0.04 vs gated-SPECT), in men (p = 0.004, n = 313) and in women (p = 0.03, n = 112) as well as in the non-infarct patients (p = 0.005, n = 186 in 1-3 vessel disease and p = 0.015, n = 140 in MVD). Conclusion: In this large multicenter, multivendor study the diagnostic performance of perfusion-CMR to detect CAD was superior to perfusion SPECT in the entire population and in sub-groups. Perfusion-CMR can be recommended as an alternative for SPECT imaging.}, language = {en} } @phdthesis{Mieck2009, author = {Mieck, Sibylle}, title = {Gr{\"o}ßen{\"a}nderung der subretinalen Membran / der Makulanarbe nach subretinaler Chirurgie bei altersabh{\"a}ngiger Makuladegeneration, im Vergleich zum Verlauf nach Laserbehandlung und ohne Therapie}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-39597}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2009}, abstract = {Die altersabh{\"a}ngige Makuladegeneration ist neben der diabetischen Makulopathie und dem Glaukom die h{\"a}ufigste Ursache f{\"u}r den irreversiblen Verlust der Lesef{\"a}higkeit und Erblindung bei {\"a}lteren Menschen in den westlichen Industriel{\"a}ndern. Diese Studie versuchte die Gr{\"o}ßen{\"a}nderung der Narbe nach subretinaler Membranexzision und nach Photokoagulation {\"u}ber einen Zeitraum von zwei Jahren anhand von Fundusfotografien und Angiographien zu analysieren. Die Arbeit beinhaltet eine retrospektive Analyse von 109 Patienten mit submakul{\"a}rer Operation und 11 Patienten mit Laserkoagulation zwischen den Jahren 1996 und 1998. Nach chirurgischer Exzision der Membranen und nach Photokoagulation kam es innerhalb von zwei Jahren nur zu einem geringen Narbenwachstum verglichen mit dem st{\"a}ndigen Membranwachstum bei den Spontanverl{\"a}ufen.}, subject = {Senile Makuladegeneration}, language = {de} } @phdthesis{Amari2003, author = {Amari, Feriel}, title = {Magnetresonanzangiographie der Becken- und Beingef{\"a}ße}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-4559}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2003}, abstract = {In einem Zeitraum von Oktober 1997 bis Mai 1998 werden an 19 Patienten 22 Untersuchungen der Becken- und Bein-Arterien sowohl in MRA-Technik als auch als i.a. DSA durchgef{\"u}hrt. Hierbei finden im Rahmen der MRA-Untersuchung in allen F{\"a}llen die zeitaufgel{\"o}ste, Kontrastmittel-unterst{\"u}tzte 3d-Flash-Sequenz und die EKG-getriggerte 2d-Flash-Multivenc-Pha-senkontrast-Sequenz Anwendung. Beide Methoden werden in der Diagnostik der pAVK von der Aortenbifurkation bis zum distalen Unterschenkel getestet und in 3 F{\"a}llen im Rahmen einer periinterventionellen Kontrolle vor und nach PTA eingesetzt. Das Patientenkollektiv setzt sich ausnahmslos aus Patienten mit pAVK zusammen, die h{\"a}ufig Nebenbefunde wie zum Beispiel einen Diabetes mellitus oder eine Niereninsuffizienz aufweisen. Die Auswertung der Angiographien erfolgt durch die Zuordnung der verschiedenen arte-riellen Abschnitte zu verschiedenen Stenosegraden und dem anschließenden statistischen Ver-gleich der Befunde der MRA und der i.a.DSA. Als Ergebnisse erhalten wir f{\"u}r die Kontrastmittel-unterst{\"u}tzte MRA eine {\"U}bereinstim-mungsrate mit der i.a. DSA von 79\% sowie eine Sensitivit{\"a}t von 96,7\% und eine Spezifit{\"a}t von 97\% f{\"u}r die Abbildung h{\"a}modynamisch relevanter Stenosen. Die Sensitivit{\"a}t f{\"u}r die Detektion von Verschl{\"u}ssen betr{\"a}gt 97,8\% und die entsprechende Spezifit{\"a}t 99,2\%. Die Phasenkontrast-MRA zeigt im Vergleich mit der i.a.DSA eine schw{\"a}chere {\"U}berein-stimmungsrate von 65,4\% sowie eine Sensitivit{\"a}t von 88,3\% und eine Spezifit{\"a}t von 85,6\% f{\"u}r die Darstellung h{\"a}modynamisch relevanter Stenosen. F{\"u}r die Diagnose eines Gef{\"a}ßverschlus-ses ist die Sensitivit{\"a}t 89\% und die Spezifit{\"a}t 91,8\%. Als Schlußfolgerung wird festgestellt, daß die MRA eine nichtinvasive, zur i.a.DSA {\"a}qui-valente Untersuchungsmethode darstellt, die bei Kontraindikationen gegen die i.a.DSA einge-setzt werden kann. Im Vergleich zur Phasenkontrast-MRA ist die Kontrastmittel-unterst{\"u}tzte MRA sowohl ein schnelleres als auch ein pr{\"a}ziseres Verfahren zur Diagnostik von Gef{\"a}ßl{\"a}sio-nen der Becken-Bein-Arterien und bietet den Vorteil der 3-dimensionalen Darstellung. Die Phasenkontrast-MRA ist insbesondere durch die einfache Durchf{\"u}hrbarkeit und die fehlende Invasivit{\"a}t ebenfalls als Verfahren zur Diagnostik der peripheren AVK denkbar, jedoch ist zur exakten Stenosegraduierung im Bereich der L{\"a}sion eine nachgeschaltete Untersuchung mit weiteren Methoden n{\"o}tig. Die MRA kann in der postinterventionellen, angiographischen Kontrolle eingesetzt werden. F{\"u}r die Empfehlung zum routinem{\"a}ßigen Einsatz in diesem Bereich sind jedoch Studien mit gr{\"o}ßeren Fallzahlen n{\"o}tig. In naher Zukunft l{\"a}ßt sich die MRA-Technik durch die Entwicklung von leistungsf{\"a}hi-geren Gradientenspulensystemen, neuen Prototypen von Oberfl{\"a}chenspulen, intelligenteren Nachverarbeitungs-Algorhytmen und Blutpool-Kontrastmitteln noch weiter optimieren. Die Evolution der MRA-Technik wird ihre Integration in die Routinediagnostik vereinfachen und ihr Indikationsspektrum erweitern.}, language = {de} }