Towards an anthropomorphic MRI phantom mimicking static and dynamic B0 field variations in the human cervical spinal cord

OBJECTIVE: field variations. The aim of this study was to develop an anthropomorphic cervical spine phantom that replicates these. MATERIALS AND METHODS: The phantom consisted of a 3D-printed head-to-thorax shell containing 3D-printed vertebrae (C1-T1) in a water-based liquid solution. An external respiration system mimicked breathing-induced field fluctuations by moving metal staples over the phantom. The accuracy of the reproduced fields was evaluated at 7 T by field maps and multi-echo GREs acquired in the phantom and in four subjects. RESULTS: Fourier-based field simulations confirmed the vertebrae to be the main contributors to the local static field in the spinal canal, providing a rationale for the phantom design. The 3D-printed vertebrae accurately reproduced the spatial field pattern encountered in vivo, but with one-third of the intensity due to lower susceptibility differences. The respiration system produced spatially and temporally similar dynamic field fluctuations as in vivo. DISCUSSION: field variations in spinal cord MRI.