Abstract
Eight- and sixteen-channel transceive stripline/TEM body arrays were compared at 7 T (297 MHz) both in simulation and experiment. Despite previous demonstrations of similar arrays for use in body applications, a quantitative comparison of the two configurations has not been undertaken to date. Results were obtained on a male pelvis for assessing transmit, signal to noise ratio, and parallel imaging performance and to evaluate local power deposition versus transmit B1 (B1+). All measurements and simulations were conducted after performing local B1+ phase shimming in the region of the prostate. Despite the additional challenges of decoupling immediately adjacent coils, the sixteen-channel array demonstrated improved or nearly equivalent performance to the eight-channel array based on the evaluation criteria. Experimentally, transmit performance and signal to noise ratio were 22% higher for the sixteen-channel array while significantly increased reduction factors were achievable in the left-right direction for parallel imaging. Finite difference time domain simulations demonstrated similar results with respect to transmit and parallel imaging performance, however, a higher transmit efficiency advantage of 33% was predicted. Simulations at both 3 and 7 T verified the expected parallel imaging improvements with increasing field strength and showed that, for a specific B1+ shimming strategy used, the sixteen-channel array exhibited lower local and global specific absorption rate for a given B1+.
Original language | English (US) |
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Pages (from-to) | 954-964 |
Number of pages | 11 |
Journal | Magnetic resonance in medicine |
Volume | 67 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2012 |
Keywords
- 7 T body imaging
- 7 tesla
- SAR
- TEM coil
- transmit/receive arrays
- ultra high field
Center for Magnetic Resonance Research (CMRR) tags
- MRE
- BI