Eight-channel decoupled array for cervical spinal cord imaging at 3T: six-channel posterior and two-channel anterior array coil

Abstract

The purpose of this study was to develop a dedicated high signal-to-noise ratio (SNR) radio frequency coil for cervical spinal cord (CSC) imaging without using the preamp decoupling technique. A novel eight-channel CSC array was constructed using butterfly, loop (circular), and rectangular elements. The adjacent elements were decoupled by the critical geometrical overlapping, and most non-adjacent elements were decoupled using the loop and butterfly elements. The performance of the proposed CSC coil was compared with the performance of the standard manufacturer's coil (Siemens' head, neck, and spine array) at 3T MRI system in T₂-weighted images, diffusion tensor images, and ultrahigh-b diffusion-weighted images. In T₂-weighted images, the SNR improvement of the eight-channel CSC coil was 1.4–2.0 times over the manufacturer's coil at the different levels of the CSC vertebrae. Higher contrast between white matter and gray matter was observed in the diffusion-weighted (b = 500 s/mm²) images and the fractional anisotropy maps obtained using the eight-channel CSC coil compared with the manufacturer's coil. The eight-channel CSC coil yielded 2.0 times higher SNR compared with the manufacturer's coil from the white matter region of the ultrahigh-b (b = 7348 s/mm²) radial diffusion-weighted images.