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Development and evaluation of a 16‐channel receive‐only RF coil to improve 7T ultra‐high field body MRI with focus on the spine
Author(s) -
Rietsch Stefan H. G.,
Brunheim Sascha,
Orzada Stephan,
Voelker Maximilian N.,
Maderwald Stefan,
Bitz Andreas K.,
Gratz Marcel,
Ladd Mark E.,
Quick Harald H.
Publication year - 2019
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.27731
Subject(s) - electromagnetic coil , radiofrequency coil , imaging phantom , signal (programming language) , signal to noise ratio (imaging) , noise (video) , focus (optics) , acoustics , torso , physics , nuclear magnetic resonance , computer science , optics , medicine , anatomy , quantum mechanics , artificial intelligence , image (mathematics) , programming language
Purpose A 16‐channel receive (16Rx) radiofrequency (RF) array for 7T ultra‐high field body MR imaging is presented. The coil is evaluated in conjunction with a 16‐channel transmit/receive (16TxRx) coil and additionally with a 32‐channel transmit/receive (32TxRx) remote body coil for RF transmit and serving as receive references. Methods The 16Rx array consists of 16 octagonal overlapping loops connected to custom‐built detuning boards with preamplifiers. Performance metrics like noise correlation, g‐factors, and signal‐to‐noise ratio gain were compared between 4 different RF coil configurations. In vivo body imaging was performed in volunteers using radiofrequency shimming, time interleaved acquisition of modes (TIAMO), and 2D spatially selective excitation using parallel transmit (pTx) in the spine. Results Lower g‐factors were obtained when using the 16Rx coil in addition to the 16TxRx array coil configuration versus the 16TxRx array alone. Distinct signal‐to‐noise ratio gain using the 16Rx coil could be demonstrated in the spine region both for a comparison with the 16TxRx coil (>50% gain) in vivo and the 32TxRx coil (>240% gain) in a phantom. The 16Rx coil was successfully applied to improve anatomical imaging in the abdomen and 2D spatially selective excitation in the spine of volunteers. Conclusion The novel 16‐channel Rx‐array as an add‐on to multichannel TxRx RF coil configurations provides increased signal‐to‐noise ratio, lower g‐factors, and thus improves 7T ultra‐high field body MR imaging.