TY - JOUR A1 - Westermaier, Thomas A1 - Linsenmann, Thomas A1 - Homola, György A. A1 - Loehr, Mario A1 - Stetter, Christian A1 - Willner, Nadine A1 - Ernestus, Ralf-Ingo A1 - Soymosi, Laszlo A1 - Vince, Giles H. T1 - 3D rotational fluoroscopy for intraoperative clip control in patients with intracranial aneurysms – assessment of feasibility and image quality JF - BMC Medical Imaging N2 - 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. KW - aneurysm surgery KW - clip control KW - angiography KW - 3D fluoroscopy KW - image quality KW - intraoperative KW - vessel patency KW - contrast KW - post-processing Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-146381 VL - 16 IS - 30 ER - TY - JOUR A1 - Schwitter, Juerg A1 - Wacker, Christian M. A1 - Wilke, Norbert A1 - Al-Saadi, Nidal A1 - Sauer, Ekkehart A1 - Huettle, Kalman A1 - Schönberg, Stefan O. A1 - Debl, Kurt A1 - Strohm, Oliver A1 - Ahlstrom, Hakan A1 - Dill, Thorsten A1 - Hoebel, Nadja A1 - Simor, Tamas T1 - 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) JF - Journal of Cardiovascular Magnetic Resonance N2 - 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. KW - coronary disease KW - perfusion KW - contrast KW - ischemia KW - women KW - emission-computed-tomography KW - noninvasive detection KW - intervention KW - randomized-trial KW - cardiovascular magnetic resonance KW - stress perfusion KW - prognostic value KW - angiography KW - scintigraphy Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134256 VL - 14 IS - 61 ER - TY - JOUR A1 - Augustin, Anne Marie A1 - Wolfschmidt, Franziska A1 - Elsässer, Thilo A1 - Sauer, Alexander A1 - Dierks, Alexander A1 - Bley, Thorsten Alexander A1 - Kickuth, Ralph T1 - Color-coded summation images for the evaluation of blood flow in endovascular aortic dissection fenestration JF - BMC Medical Imaging N2 - 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. KW - angiography KW - fenestration KW - color-coding KW - aortic dissection KW - DSA KW - endovascular Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-301107 VL - 22 IS - 1 ER -