A patient-friendly 16-channel transmit/64-channel receive coil array for combined head–neck MRI at 7 Tesla

Abstract

Purpose: To extend the coverage of brain coil arrays to the neck and cervical–spine region to enable combined head and neck imaging at 7 Tesla (T) ultra-high field MRI. Methods: The coil array structures of a 64-channel receive coil and a 16-channel transmit coil were merged into one anatomically shaped close-fitting housing. Transmit characteristics were evaluated in a B1+-field mapping study and an electromagnetic model. Receive SNR and the encoding capability for accelerated imaging were evaluated and compared with a commercially available 7 T brain array coil. The performance of the head–neck array coil was demonstrated in human volunteers using high-resolution accelerated imaging. Results: In the brain, the SNR matches the commercially available 32-channel brain array and showed improvements in accelerated imaging capabilities. More importantly, the constructed coil array improved the SNR in the face area, neck area, and cervical spine by a factor of 1.5, 3.4, and 5.2, respectively, in regions not covered by 32-channel brain arrays at 7 T. The interelement coupling of the 16-channel transmit coil ranged from −14 to −44 dB (mean = −19 dB, adjacent elements