TY - CHAP A1 - Fissabre, Anke ED - Naujokat, Anke ED - Hake, Verena ED - Schindler, Bruno ED - Schötten, Björn T1 - Eine moderne Sainte-Chapelle in Köln. Otto Bartnings Stahlkirche auf der Pressa 1928 T2 - Baugedanken: Einsichten, Ansichten, Aussichten für Jan Pieper zum 80. Geburtstag Y1 - 2024 SN - 978-3-943164-87-9 SP - 66 EP - 81 PB - Geymüller Verag für Architektur CY - Aachen ER - TY - JOUR A1 - Aliazizi, Fereshteh A1 - Özsoylu, Dua A1 - Bakhshi Sichani, Soroush A1 - Khorshid, Mehran A1 - Glorieux, Christ A1 - Robbens, Johan A1 - Schöning, Michael J. A1 - Wagner, Patrick T1 - Development and Calibration of a Microfluidic, Chip-Based Sensor System for Monitoring the Physical Properties of Water Samples in Aquacultures JF - Micromachines N2 - In this work, we present a compact, bifunctional chip-based sensor setup that measures the temperature and electrical conductivity of water samples, including specimens from rivers and channels, aquaculture, and the Atlantic Ocean. For conductivity measurements, we utilize the impedance amplitude recorded via interdigitated electrode structures at a single triggering frequency. The results are well in line with data obtained using a calibrated reference instrument. The new setup holds for conductivity values spanning almost two orders of magnitude (river versus ocean water) without the need for equivalent circuit modelling. Temperature measurements were performed in four-point geometry with an on-chip platinum RTD (resistance temperature detector) in the temperature range between 2 °C and 40 °C, showing no hysteresis effects between warming and cooling cycles. Although the meander was not shielded against the liquid, the temperature calibration provided equivalent results to low conductive Milli-Q and highly conductive ocean water. The sensor is therefore suitable for inline and online monitoring purposes in recirculating aquaculture systems. KW - chip-based sensor setup KW - aquaculture KW - microfluidics KW - impedance spectroscopy KW - thermometry KW - electrical conductivity of liquids Y1 - 2024 U6 - https://doi.org/10.3390/mi15060755 SN - 2072-666X N1 - This article belongs to the Special Issue "Multisensor Arrays" N1 - Corresponding author: Michael J. Schöning VL - 15 IS - 6 PB - MDPI CY - Basel ER - TY - GEN A1 - Frauenrath, Tobias A1 - Dieringer, Matthias A1 - Patel, Nishant A1 - Zerdem, Celal A1 - Hentschel, Jan A1 - Renz, Wolfgang A1 - Niendorf, Thoralf T1 - From Artifact to Merit: Cardiac Gated MRI at 7T & 3T using Magneto-Hydrodynamic Effects for Synchronization T2 - 2011 ISMRM Annual Meeting Proceedings N2 - ECG is corrupted by magneto-hydrodynamic effects at higher magnetic field strength. Artifacts in the ECG trace and severe T-wave elevation might be mis-interpreted as R-waves. MHD being inherently sensitive to blood flow and blood velocity provides an alternative approach for cardiac gating, even in peripheral target areas far away from the commonly used upper torso positions of ECG electrodes. This feature would be very beneficial to address traveling time induced motion artifacts and trigger latency related issues raised by ECG-gated peripheral MR angiography. For all those reasons, this work proposes the use of MHD-trigger for cardiac gated MR. Y1 - 2011 SN - 1545-4428 N1 - ISMRM 19th Annual Meeting & Exhibition, 7-13 May 2011, Montreal, Quebec, Canada ER - TY - GEN A1 - Frauenrath, Tobias A1 - de Geyer d'Orth, Thibaut A1 - Niendorf, Thoralf T1 - Assessment of Accuracy & Reproducibility of ECG, Pulse Oximetry & Phonocardiogram Gating of Cardiac MRI at 7T T2 - 2011 ISMRM Annual Meeting Proceedings N2 - At (ultra)high magnetic fields the artifact sensitivity of ECG recordings increases. This bears the risk of R-wave mis-registration which has been consistently reported for ECG triggered CMR at 7.0T. Realizing the constraints of conventional ECG, acoustic cardiac triggering (ACT) has been proposed. The clinical ACT has not been carefully examined yet. For this reason, this work scrutinizes the suitability, accuracy and reproducibility of ACT for CMR at 7.0T. For this purpose, the trigger reliability and trigger detection variance are examined together with an qualitative and quantitative assessment of image quality of the heart at 7.0T. Y1 - 2011 SN - 1545-4428 N1 - ISMRM 19th Annual Meeting & Exhibition, 7-13 May 2011, Montreal, Quebec, Canada ER - TY - GEN A1 - Martin, Conrad Steven A1 - Frauenrath, Tobias A1 - Zerdem, Celal A1 - Renz, Wolfgang A1 - Niendorf, Thoralf T1 - Evaluation of Magneto Alert Sensor (MALSE) to Improve MR Safety by Decreasing the Incidence of Ferromagnetic Projectile Accidents T2 - 2011 ISMRM Annual Meeting Proceedings N2 - The magnetic forces of fringe magnetic fields of MR systems on ferromagnetic components can impose a severe patient, occupational health and safety hazard. MRI accidents are listed as number 9 of the top 10 risks in modern medicine. With the advent of ultrahigh field MR systems including passively shielded magnet versions, this risk, commonly known as the missile or projectile effect is even more pronounced. A strategy employing magnetic field sensors which can be attached to ferromagnetic objects that are commonly used in a clinical environment is conceptually appealing for the pursuit of reducing the risk of ferromagnetic projectile accidents. Y1 - 2011 SN - 1545-4428 N1 - ISMRM 19th Annual Meeting & Exhibition, 7-13 May 2011, Montreal, Quebec, Canada ER - TY - GEN A1 - Frauenrath, Tobias A1 - Renz, Wolfgang A1 - Rieger, Jan A1 - Gömmel, Andreas A1 - Butenweg, Christoph A1 - Niendorf, Thoralf T1 - High Spatial Resolution 3D MRI of the Larynx Using a Dedicated TX/RX Phased Array Coil at 7.0T T2 - 2010 ISMRM-ESMRMB joint annual meeting N2 - MRI holds great potential for elucidating laryngeal and vocal fold anatomy together with the assessment of physiological processes associated in human phonation. However, MRI of human phonation remains very challenging due to the small size of the targeted structures, interfering signal from fat, air between the vocal folds and surrounding muscles and physiological motion. These anatomical/physiological constraints translate into stringent technical requirements in balancing, scan time, image contrast, immunity to physiological motion, temporal resolution and spatial resolution. Motivated by these challenges and limitations this study is aiming at translating the sensitivity gain at ultra-high magnetic fields for enhanced high spatial resolution 3D imaging of the larynx and vocal tract. To approach this goal a dedicated two channel TX/RX larynx coil is being proposed. Y1 - 2010 SN - 1545-4428 N1 - ISMRM-ESMRMB joint annual meeting, 1 - 7 May 2010, Stockholm, Sweden ER - TY - GEN A1 - Hezel, Fabian A1 - Frauenrath, Tobias A1 - Renz, Wolfgang A1 - Schulz-Menger, Jeanette A1 - Niendorf, Thoralf T1 - Feasibility of CINE Myocardial T2* Mapping Using Susceptibility Weighted Gradient-Echo Imaging at 7.0 T T2 - 2010 ISMRM-ESMRMB joint annual meeting N2 - This study is designed to demonstrate the promise of susceptibility weighted 2D CINE FLASH and T2* Mapping of the heart at 7T. Y1 - 2010 SN - 1545-4428 N1 - ISMRM-ESMRMB joint annual meeting, 1 - 7 May 2010, Stockholm, Sweden ER - TY - GEN A1 - Frauenrath, Tobias A1 - Becker, Meike A1 - Hezel, Fabian A1 - Krombach, Gabriele A. A1 - Kremer, Ute A1 - Schulz-Menger, Jeanette A1 - Niendorf, Thoralf T1 - Comparison of Left Function Assessment Using Phonocardiogram and Electrocardiogram Triggered 2D SSFP CINE MR Imaging at 1.5 T and 3.0 T T2 - 2010 ISMRM-ESMRMB joint annual meeting N2 - As high-field cardiac MRI (CMR) becomes more widespread the propensity of ECG to distortions and mistriggering increases and with it the motivation for a cardiac triggering alternative. Hence, this study explores the suitability of acoustic cardiac triggering (ACT) for left ventricular (LV) function assessment in healthy subjects at 1.5T and 3.0T. Y1 - 2010 SN - 1545-4428 N1 - ISMRM-ESMRMB joint annual meeting, 1 - 7 May 2010, Stockholm, Sweden ER - TY - GEN A1 - Dieringer, Matthias A. A1 - Renz, Wolfgang A1 - Lindel, Tomasz A1 - Seifert, Frank A1 - Frauenrath, Tobias A1 - Waiczies, Helmar A1 - von Knobelsdorff-Brenkhoff, Florian A1 - Santoro, Davide A1 - Hoffmann, Werner A1 - Ittermann, Bernd A1 - Schulz-Menger, Jeanette A1 - Niendorf, Thoralf T1 - 4CH TX/RX Surface Coil for 7T: Design, Optimization and Application for Cardiac Function Imaging T2 - 2010 ISMRM-ESMRMB joint annual meeting N2 - Practical impediments of ultra high field cardiovascular MR (CVMR) can be catalogued in exacerbated magnetic field and radio frequency (RF) inhomogeneities, susceptibility and off-resonance effects, conductive and dielectric effects in tissue, and RF power deposition constraints, which all bear the potential to spoil the benefit of CVMR at 7T. Therefore, a four element cardiac transceive surface coil array was developed. Cardiac imaging provided clinically acceptable signal homogeneity with an excellent blood myocardium contrast. Subtle anatomic structures, such as pericardium, mitral and tricuspid valves and their apparatus, papillary muscles, and trabecles were accurately delineated. Y1 - 2010 SN - 1545-4428 N1 - ISMRM-ESMRMB joint annual meeting, 1 - 7 May 2010, Stockholm, Sweden ER - TY - JOUR A1 - Fiedler, Thomas M. A1 - Orzada, Stephan A1 - Flöser, Martina A1 - Rietsch, Stefan H. G. A1 - Quick, Harald H. A1 - Ladd, Mark E. A1 - Bitz, Andreas T1 - Performance analysis of integrated RF microstrip transmit antenna arrays with high channel count for body imaging at 7 T JF - NMR in Biomedicine N2 - The aim of the current study was to investigate the performance of integrated RF transmit arrays with high channel count consisting of meander microstrip antennas for body imaging at 7 T and to optimize the position and number of transmit ele- ments. RF simulations using multiring antenna arrays placed behind the bore liner were performed for realistic exposure conditions for body imaging. Simulations were performed for arrays with as few as eight elements and for arrays with high channel counts of up to 48 elements. The B1+ field was evaluated regarding the degrees of freedom for RF shimming in the abdomen. Worst-case specific absorption rate (SARwc ), SAR overestimation in the matrix compression, the number of virtual obser- vation points (VOPs) and SAR efficiency were evaluated. Constrained RF shimming was performed in differently oriented regions of interest in the body, and the devia- tion from a target B1+ field was evaluated. Results show that integrated multiring arrays are able to generate homogeneous B1+ field distributions for large FOVs, espe- cially for coronal/sagittal slices, and thus enable body imaging at 7 T with a clinical workflow; however, a low duty cycle or a high SAR is required to achieve homoge- neous B1+ distributions and to exploit the full potential. In conclusion, integrated arrays allow for high element counts that have high degrees of freedom for the pulse optimization but also produce high SARwc , which reduces the SAR accuracy in the VOP compression for low-SAR protocols, leading to a potential reduction in array performance. Smaller SAR overestimations can increase SAR accuracy, but lead to a high number of VOPs, which increases the computational cost for VOP evaluation and makes online SAR monitoring or pulse optimization challenging. Arrays with interleaved rings showed the best results in the study. KW - body imaging at UHF MRI KW - integrated transmit coil arrays KW - VOP compression Y1 - 2021 U6 - https://doi.org/10.1002/nbm.4515 SN - 0952-3480 (ISSN) SN - 1099-1492 (eISSN) VL - 34 IS - 7 PB - Wiley CY - Weinheim ER -