TY - JOUR A1 - Sherif, Mohammad A. A1 - Herold, Joerg A1 - Voelker, Wolfram A1 - Maniuc, Octavian A1 - Ertl, Georg A1 - Praast, Christian A1 - Braun-Dullaeus, Ruediger Christian T1 - Feasibility of a new method using two-dimensional transesophageal echocardiography for aortic annular sizing in patients undergoing transcatheter aortic valve implantation; a case-control study JF - BMC Cardiovascular Disorders N2 - Background: Accurate preoperative assessment of the aortic annulus dimension is crucial for successful transcatheter aortic valve implantation (TAVI). In this study we validated a new method using two-dimensional transesophageal echocardiography (2D-TEE) for measurement of the aortic annulus prior to TAVI. Methods: We analysed 124 patients who underwent successful TAVI using a self-expandable prosthesis, divided equally into two groups; in the study group we used the cross sectional short axis 2D-TEE for measurement of the aortic annulus and in the control group we used the long axis 2D-TEE. Results: Both groups were comparable regarding the clinical parameters. On the other hand, patients in the study group had less left ventricular ejection fraction (38.9 % versus 45.6 %, p = 0.01). The aortic valve annulus was, although not statistically significant, smaller in the study group (21.58 versus 23.28 mm, p = 0.25). Post procedural quantification of the aortic regurgitation revealed that only one patient in both groups had severe aortic regurgitation (AR), in this patient the valve was implanted deep. The incidence of significant AR was higher in the control group (29.0 % versus 12.9 %, p = 0.027). Conclusions: Sizing of the aortic valve annulus using cross-sectional 2D-TEE offers a safe and plausible method for patients undergoing TAVI using the self-expandable prosthesis and is significantly superior to using long axis 2D-TEE. KW - paravalvular regurgitation KW - multicenter KW - management KW - sizing KW - echocardiography KW - replacement KW - tomography KW - guidelines KW - outcomes KW - impact KW - recommendations KW - stenosis KW - TAVI Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148328 VL - 15 IS - 78 ER - TY - JOUR A1 - Elhfnawy, Ahmed Mohamed A1 - Elsalamawy, Doaa A1 - Abdelraouf, Mervat A1 - Schliesser, Mira A1 - Volkmann, Jens A1 - Fluri, Felix T1 - Red flags for a concomitant giant cell arteritis in patients with vertebrobasilar stroke: a cross-sectional study and systematic review JF - Acta Neurologica Belgica N2 - Giant cell arteritis (GCA) may affect the brain-supplying arteries, resulting in ischemic stroke, whereby the vertebrobasilar territory is most often involved. Since etiology is unknown in 25% of stroke patients and GCA is hardly considered as a cause, we examined in a pilot study, whether screening for GCA after vertebrobasilar stroke might unmask an otherwise missed disease. Consecutive patients with vertebrobasilar stroke were prospectively screened for GCA using erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), hemoglobin, and halo sign of the temporal and vertebral artery on ultrasound. Furthermore, we conducted a systematic literature review for relevant studies. Sixty-five patients were included, and two patients (3.1%) were diagnosed with GCA. Patients with GCA were older in age (median 85 versus 69 years, p = 0.02). ESR and CRP were significantly increased and hemoglobin was significantly lower in GCA patients compared to non-GCA patients (median, 75 versus 11 mm in 1 h, p = 0.001; 3.84 versus 0.25 mg/dl, p = 0.01, 10.4 versus 14.6 mg/dl, p = 0.003, respectively). Multiple stenoses/occlusions in the vertebrobasilar territory affected our two GCA patients (100%), but only five (7.9%) non-GCA patients (p = 0.01). Our literature review identified 13 articles with 136 stroke patients with concomitant GCA. Those were old in age. Headache, increased inflammatory markers, and anemia were frequently reported. Multiple stenoses/occlusions in the vertebrobasilar territory affected around 70% of stroke patients with GCA. Increased inflammatory markers, older age, anemia, and multiple stenoses/occlusions in the vertebrobasilar territory may be regarded as red flags for GCA among patients with vertebrobasilar stroke. KW - giant cell arteritis KW - vertebrobasilar stroke KW - blood sedimentation KW - C-reactive protein KW - hemoglobin KW - stenosis Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-315610 SN - 0300-9009 SN - 2240-2993 VL - 120 IS - 6 ER - TY - JOUR A1 - Herz, Stefan A1 - Stefanescu, Maria R. A1 - Lohr, David A1 - Vogel, Patrick A1 - Kosmala, Aleksander A1 - Terekhov, Maxim A1 - Weng, Andreas M. A1 - Grunz, Jan-Peter A1 - Bley, Thorsten A. A1 - Schreiber, Laura M. T1 - Effects of image homogeneity on stenosis visualization at 7 T in a coronary artery phantom study: With and without B1-shimming and parallel transmission JF - PloS One N2 - Background To investigate the effects of B\(_1\)-shimming and radiofrequency (RF) parallel transmission (pTX) on the visualization and quantification of the degree of stenosis in a coronary artery phantom using 7 Tesla (7 T) magnetic resonance imaging (MRI). Methods Stenosis phantoms with different grades of stenosis (0%, 20%, 40%, 60%, 80%, and 100%; 5 mm inner vessel diameter) were produced using 3D printing (clear resin). Phantoms were imaged with four different concentrations of diluted Gd-DOTA representing established arterial concentrations after intravenous injection in humans. Samples were centrally positioned in a thorax phantom of 30 cm diameter filled with a custom-made liquid featuring dielectric properties of muscle tissue. MRI was performed on a 7 T whole-body system. 2D-gradient-echo sequences were acquired with an 8-channel transmit 16-channel receive (8 Tx / 16 Rx) cardiac array prototype coil with and without pTX mode. Measurements were compared to those obtained with identical scan parameters using a commercially available 1 Tx / 16 Rx single transmit coil (sTX). To assess reproducibility, measurements (n = 15) were repeated at different horizontal angles with respect to the B0-field. Results B\(_1\)-shimming and pTX markedly improved flip angle homogeneity across the thorax phantom yielding a distinctly increased signal-to-noise ratio (SNR) averaged over a whole slice relative to non-manipulated RF fields. Images without B\(_1\)-shimming showed shading artifacts due to local B\(_1\)\(^+\)-field inhomogeneities, which hampered stenosis quantification in severe cases. In contrast, B\(_1\)-shimming and pTX provided superior image homogeneity. Compared with a conventional sTX coil higher grade stenoses (60% and 80%) were graded significantly (p<0.01) more precise. Mild to moderate grade stenoses did not show significant differences. Overall, SNR was distinctly higher with B\(_1\)-shimming and pTX than with the conventional sTX coil (inside the stenosis phantoms 14%, outside the phantoms 32%). Both full and half concentration (10.2 mM and 5.1 mM) of a conventional Gd-DOTA dose for humans were equally suitable for stenosis evaluation in this phantom study. Conclusions B\(_1\)-shimming and pTX at 7 T can distinctly improve image homogeneity and therefore provide considerably more accurate MR image analysis, which is beneficial for imaging of small vessel structures. KW - stenosis KW - magnetic resonance imaging KW - thorax KW - in vivo imaging KW - coronary arteries KW - image processing KW - 3D printing KW - signal to noise ratio Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-300129 VL - 17 IS - 6 ER -