Effective arrangement of separated transmit-only/receive-only RF coil for improvement of B1 homogeneity at 7 Tesla

This article presents an effective arrangement with shifted transmit (Tx)-only and receive (Rx)-only (TORO) radiofrequency (RF) coils in a single-channel surface coil for improving the magnetic flux ( B ₁) homogeneity in an ultra-high field (UHF) magnetic resonance imaging (MRI) scanner. The proposed new methodology for the coil arrangement using the shifted TORO RF coils was demonstrated for coils with 50-mm, 100-mm, and 150-mm-square surfaces and the results were compared to those for general Tx/Rx surface coils with the same dimensions. The computational analysis indicated that a homogeneous B₁ field was achieved when the Rx-only coil was shifted in the two-dimensional xy-plane away from the Tx-only coils. Because the proposed coil configuration provides a unique opportunity for increasing the B ₁ homogeneity, this feature is likely to increase the feasibility via new coil arrangements of UHF surface design and fabrication.