Robin Etzel^1,2, Choukri Mekkaoui³, Ekaterina S Ivshina⁴, Alina Scholz¹, Markus W May¹, Nicolas Kutscha¹, Matthäus Poniatowski¹, Chaimaa Chemlali¹, Anpreet Ghotra¹, Sam-Luca JD Hansen¹, Timothy G Reese³, Lawrence L Wald³, Andreas H Mahnken², and Boris Keil^1
1Institute of Medical Physics and Radiation Protection, Department of Life Science Engineering, TH Mittelhessen University of Applied Sciences, Giessen, Germany, ²Philipps-University of Marburg, Department of Diagnostic and Interventional Radiology, Marburg, Germany, ³Harvard Medical School, Massachusetts General Hospital, Department of Radiology, A.A. Martinos Center for Biomedical Imaging, Boston, MA, United States, ⁴Princeton University, Princeton, NJ, United States

To determine the optimum configuration of a 64-channel array coil for highly accelerated in vivo cardiac diffusion-weighted imaging (DWI), the encoding capability and sensitivity of three 64-channel arrays were designed, constructed, and evaluated. Simultaneous multi-slice (SMS) acceleration enabled enhanced efficiency of the diffusion acquisitions. The array configuration with a non-uniformly distributed loop density showed the most favorable cardiac imaging performance in both SNR and SMS encoding power. Cardiac DWI of a healthy volunteer mirrors the findings from phantom evaluation and testing. Such technically advanced coils are an important component for translation of cardiac DWI to clinical settings.

Bernhard Gruber^1,2, Jason P. Stockmann¹, Azma Mareyam¹, Boris Keil³, Anpreet Ghotra³, David A. Feinberg⁴, and Lawrence L. Wald^1
1Department of Radiology, A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States, ²High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Vienna, Austria, ³Department of Life Science Engineering, Institute of Medical Physics and Radiation Protection, Mittelhessen University of Applied Science, Giessen, Germany, ⁴Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States

A 128-channel receive array for cortical brain imaging at 7T was simulated and constructed. The tight-fitting brain-only coil was designed for use with a recently constructed head gradient system (Gmax = 200 mT/m and Smax = 900mT/m/s) for use with either a single channel birdcage Tx or a 24-channel pTx coil. The goal was to maximize cortical SNR and achieve the high acceleration needed for single-shot EPI based fMRI at high sub-millimeter isotropic resolution.

Russell Luke Lagore¹, Steve Jungst¹, Jerahmie Radder¹, Edward J Auerbach¹, Steen Moeller¹, Andrea Grant¹, Lance DelaBarre¹, Matthew Waks¹, Pierre-Francois Van de Moortele¹, Gregor Adriany¹, and Kamil Ugurbil^1
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States

A 128-channel receive array has been designed and prototyped for human head imaging at 10.5T. The coil employs miniaturized electronics and flexible PCB laminates for loop conductors. Bench measurements and MR experimental results for an 8-channel cluster of loops are presented which show low coil coupling and good stability during echo-planar imaging. Electromagnetic simulations will provide an estimate for the SNR gain that can be expected from this 128-channel receive array over a 64-channel receive array tuned to the same frequency. This simulation estimate will be verified with experimental results which will include intrinsic SNR and g-factor maps.

Jiying Dai^1,2, Tijl A. van der Velden¹, Johannes M. Hoogduin¹, Fabian Bartel², Ettore F Meliadò^1,2, Mark van Uden², Catalina S. Arteaga de Castro², Evita C. Wiegers¹, Martijn Froeling¹, Mark Gosselink¹, Alexander J. E. Raaijmakers^1,3, and Dennis W. J. Klomp^1,4
1Radiology, UMC Utrecht, Utrecht, Netherlands, ²Tesla Dynamic Coils, Zaltbommel, Netherlands, ³Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, ⁴Tesla Engineering Ltd, West Sussex, United Kingdom

Multi-nuclei magnetic resonance imaging and spectroscopy are interesting techniques to study metabolism, treatment efficacy tracking, and early diagnoses of many diseases. However, there are challenges to acquire high-quality MR images or spectra of nuclei other than proton, for example, much lower signal level, as well as the inconvenience of switching RF hardware in between scans, which leads to repositioning of the subject and extra preparation time. To overcome the above issues, we developed a quintuple-tuned RF coil for sensitive whole-brain scans, targeting five nuclei: ¹H, ¹⁹F, ³¹P, ²³Na and ¹³C. Bench tests and in-vivo scans have shown promising SNR. 

Nader Tavaf¹, Steve Jungst¹, Russell L. Lagore¹, Jerahmie Radder¹, Steen Moeller¹, Andrea Grant¹, Edward Auerbach¹, Kamil Ugurbil¹, Gregor Adriany¹, and Pierre-Francois Van de Moortele^1
1Center for Magnetic Resonance Research (CMRR), University of Minnesota Twin Cities, Minneapolis, MN, United States

Receive arrays play a major role in capturing the signal-to-noise ratio (SNR) and parallel imaging performance improvements at ultrahigh-field MRI. A novel self-decoupled 64-channel receive array was built for human brain imaging and compared to a 32-channel receive array at 10.5T/447MHz. Experiments demonstrated a maximum noise correlation of 0.31 in the 64-channel receiver. Experimental SNR comparisons showed 1.95 times more SNR averaged over the sample relative to the 32-channel array at 10.5T. The 10.5T 32 channel receiver was previously shown to have 1.81 times more average SNR gain over the industry standard 32 channel array at 7T.

Ibrahim A. Elabyad¹, Maxim Terekhov¹, and Laura M. Schreiber^1
1Chair of Molecular and Cellular Imaging, Comprehensive Heart Failure Center (CHFC), University Hospital Wuerzburg, Wuerzburg, Germany

Two antisymmetric, 16-elements, transceiver RF-coil arrays were developed for improved $$${B_1^+}$$$-shimming and parallel imaging for cardiac-MRI in humans at 7T. The first array (Design1) comprised of an 8-loops for both anterior and posterior sections. The second array (Design2) was composed of 12-loops for the anterior section and 4-loops for the posterior section. Electromagnetic-field (EMF) simulations were carried out for both arrays loaded with an elliptical phantom and two human models (Duke and Ella). Static-phase $$${B_1^+}$$$-shimming has been carried out for both arrays with two different optimization cost functions to maximize the transmit-efficiency and weighted combination of $$${B_1^+}$$$-field homogeneity and transmit-efficiency.

Markus W. May¹, Sam-Luca J.D. Hansen¹, Nicolas Kutscha¹, Gurinder Kaur Multani¹, Mirsad Mahmutovic¹, Matthäus Poniatowski¹, Rene Gumbrecht², Ralph Kimmlingen², Markus Adriany², Yulin Chang³, Bastien Guerin⁴, Christina Triantafyllou², Lawrence L. Wald⁴, and Boris Keil^1
1Institute of Medical Physics and Radiation Protection (IMPS), TH Mittelhessen University of Applied Sciences, Giessen, Germany, ²Siemens Healthcare GmbH, Erlangen, Germany, ³Siemens Medical Solutions USA, Inc., Malvern, PA, United States, ⁴A.A. Martinos Center for Biomedical Imaging, Dept of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States

A 16chTx / 64chRx head-neck array coil was designed, constructed, and validated at 7T ultra-high field (UHF) MRI. The clinical benefits of UHF neuroimaging were increased by extending coil coverage from the brain region to include the cervical spine. To increase patient compliance, the commonly employed separated transmit and receive coil array functionalities at UFH were combined into one anatomically shaped close-fitting housing which is fully splitable for patient access.

Shajan Gunamony^1,2, Roland Müller³, Paul McElhinney¹, Sydney Nicole Williams¹, Nicolas Groß-Weege^3,4, Nikolaus Weiskopf^3,5, Harald E Möller³, and David Feinberg^6
1Imaging Centre of Excellence, University of Glasgow, Glasgow, United Kingdom, ²MR CoilTech Limited, Glasgow, United Kingdom, ³Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, ⁴Siemens Healthcare GmbH, Erlangen, Germany, ⁵Faculty of Physics and Earth Sciences, Felix Bloch Institute for Solid State Physics, Leipzig, Germany, ⁶Helen Wills Neuroscience Institute, University of California, Berkeley, CA, United States

The NexGen 7T scanner has been designed to reach an unprecedented microscale resolution in fMRI studies of the cerebral cortex. A radiofrequency coil setup with a high density receive array is essential to capture the promised benefits. The coil design, which is already constrained by the limited space on the patient table inside the head gradient, must be robust, allow routine scanning and offer a visual field to support fMRI studies. We have developed a compact 16-channel transmit 96-channel receive head coil for the NexGen 7T scanner. In this abstract, we present the coil development and preliminary phantom results.

Adam Maunder¹, Ashwin Iyer², and Nicola De Zanche^1
1Oncology, Medical Physics, Cross Cancer Institute, University of Alberta, Edmonton, AB, Canada, ²Electrical and Computer Engineering, University of Alberta, Edmonton, AB, Canada

The maximum local specific absorption rate relative to B₁⁺ field produced increases with B₀ field strength. This relationship greatly constrains the parameter space in sequence optimization due to safety limits. The metamaterial liner simulated here produces lower SAR for the same transmit excitation compared to conventional birdcage coils for whole body imaging, thereby permitting more power-intensive scan parameters to be used. The transmit efficiency and homogeneity is found to be similar between the metamaterial liner and comparable birdcage coil, while the metamaterial liner produces only 41% of the 10g localized SAR for the same transmit field.

Ria Forner¹, Kyung Min Nam¹, Tijl van der Velden¹, and Dennis Klomp^1
1UMC Utrecht, Utrecht, Netherlands

Here we present the very first ³¹P MRS data in the human tongue at 7T. Three different receive coils were designed and evaluated to compare their performance: two each inside the mouth: a loop and also a saddle coil and a 3-channel loop array positioned externally. The transmit setup consists of an integrated ³¹P body birdcage coil for ³¹P transmit and an array of 8 ¹H dipoles for image registration. The loop coil seems to outperform the other two coils albeit that signals may originate from jaw. For voxels inside the tongue, relatively high phosphomonoesters were observed in all volunteers.