TY - GEN A1 - Lindel, Tomasz Dawid A1 - Greiser, Andreas A1 - Waxman, Patrick A1 - Dietterle, Martin A1 - Seifert, Frank A1 - Fontius, Ulrich A1 - Renz, Wolfgang A1 - Dieringer, Matthias A. A1 - Frauenrath, Tobias A1 - Schulz-Menger, Jeanette A1 - Niendorf, Thoralf A1 - Ittermann, Bernd T1 - Cardiac CINE MRI at 7 T using a transmit array T2 - 2012 ISMRM Annual Meeting Proceedings N2 - With its need for high SNR and short acquisition times, Cardiac MRI (CMR) is an intriguing target application for ultrahigh field MRI. Due to the sheer size of the upper torso, however, the known RF issues of 7T MRI are also most prominent in CMR. Recent years brought substantial progress but the full potential of the ultrahigh field for CMR is yet to be exploited. Parallel transmission (pTx) is a promising approach in this context and several groups have already reported B1 shimming for 7T CMR. In such a static pTx application amplitudes and phases of all Tx channels are adjusted individually but otherwise imaging techniques established in current clinical practice 1.5 T and 3 T are applied. More advanced forms of pTx as spatially selective excitation (SSE) using Transmit SENSE promise additional benefits like faster imaging with reduced fields of view or improved SAR control. SSE requires the full dynamic capabilities of pTx, however, and for the majority of today's implemented pTx hardware the internal synchronization of the Tx array does not easily permit external triggering as needed for CMR. Here we report a software solution to this problem and demonstrate the feasibility of CINE CMR at 7 T using a Tx array. Y1 - 2012 SN - 1545-4428 N1 - ISMRM 20th Annual Meeting & Exhibition, 5-11 May 2012, Melbourne, Australia ER - TY - JOUR A1 - Dieringer, Matthias A. A1 - Renz, Wolfgang A1 - Lindel, Tomasz D. A1 - Seifert, Frank A1 - Frauenrath, Tobias A1 - von Knobelsdorf-Brenkenhoff, Florian A1 - Waiczies, Helmar A1 - Hoffmann, Werner A1 - Rieger, Jan A1 - Pfeiffer, Harald A1 - Ittermann, Bernd A1 - Schulz-Menger, Jeanette A1 - Niendorf, Thoralf T1 - Design and application of a four-channel transmit/receive surface coil for functional cardiac imaging at 7T JF - Journal of Magnetic Resonance Imaging N2 - Purpose To design and evaluate a four-channel cardiac transceiver coil array for functional cardiac imaging at 7T. Materials and Methods A four-element cardiac transceiver surface coil array was developed with two rectangular loops mounted on an anterior former and two rectangular loops on a posterior former. specific absorption rate (SAR) simulations were performed and a Burn:x-wiley:10531807:media:JMRI22451:tex2gif-stack-1 calibration method was applied prior to obtain 2D FLASH CINE (mSENSE, R = 2) images from nine healthy volunteers with a spatial resolution of up to 1 × 1 × 2.5 mm3. Results Tuning and matching was found to be better than 10 dB for all subjects. The decoupling (S21) was measured to be >18 dB between neighboring loops, >20 dB for opposite loops, and >30 dB for other loop combinations. SAR values were well within the limits provided by the IEC. Imaging provided clinically acceptable signal homogeneity with an excellent blood-myocardium contrast applying the Burn:x-wiley:10531807:media:JMRI22451:tex2gif-stack-2 calibration approach. Conclusion A four-channel cardiac transceiver coil array for 7T was built, allowing for cardiac imaging with clinically acceptable signal homogeneity and an excellent blood-myocardium contrast. Minor anatomic structures, such as pericardium, mitral, and tricuspid valves and their apparatus, as well as trabeculae, were accurately delineated. Y1 - 2011 U6 - https://doi.org/10.1002/jmri.22451 SN - 1522-2586 VL - 33 IS - 3 SP - 736 EP - 741 PB - Wiley-Liss CY - New York ER - TY - JOUR A1 - Gräßl, Andreas A1 - Renz, Wolfgang A1 - Hezel, Fabian A1 - Dieringer, Matthias A. A1 - Winter, Lukas A1 - Özerdem, Celal A1 - Rieger, Jan A1 - Kellmann, Peter A1 - Santoro, Davide A1 - Lindel, Tomasz D. A1 - Frauenrath, Tobias A1 - Pfeiffer, Harald A1 - Niendorf, Thoralf T1 - Modular 32-channel transceiver coil array for cardiac MRI at 7.0T JF - Magnetic Resonance in Medicine N2 - Purpose To design and evaluate a modular transceiver coil array with 32 independent channels for cardiac MRI at 7.0T. Methods The modular coil array comprises eight independent building blocks, each containing four transceiver loop elements. Numerical simulations were used for B1+ field homogenization and radiofrequency (RF) safety validation. RF characteristics were examined in a phantom study. The array's suitability for accelerated high spatial resolution two-dimensional (2D) FLASH CINE imaging of the heart was examined in a volunteer study. Results Transmission field adjustments and RF characteristics were found to be suitable for the volunteer study. The signal-to-noise intrinsic to 7.0T together with the coil performance afforded a spatial resolution of 1.1 × 1.1 × 2.5 mm3 for 2D CINE FLASH MRI, which is by a factor of 6 superior to standardized CINE protocols used in clinical practice at 1.5T. The 32-channel transceiver array supports one-dimensional acceleration factors of up to R = 4 without impairing image quality significantly. Conclusion The modular 32-channel transceiver cardiac array supports accelerated and high spatial resolution cardiac MRI. The array is compatible with multichannel transmission and provides a technological basis for future clinical assessment of parallel transmission techniques at 7.0T. Y1 - 2013 U6 - https://doi.org/10.1002/mrm.24903 SN - 1522-2594 VL - 72 IS - 1 SP - 276 EP - 290 PB - Wiley-Liss CY - New York 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 -