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  - 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  -