Design, construction and performance testing of a 1.5 T cryogen-free low-temperature superconductor whole-body MRI magnet
Yulin Wang, Sucong Wang, Ping Liang, Vladimir Brusić, Jie Zeng, Bingjian Liu, Yu‐Wei Ge, Jianjun Zheng, Jingfeng Zhang, Chengbo Wang
Abstract
Abstract This work describes the design, construction and testing of a 1.5 T cryogen-free low-temperature superconductor niobium–titanium whole-body magnet with a bore diameter of 850 mm that is suitable for clinical magnetic resonance imaging (MRI) applications. The magnet is actively shielded and passively shimmed to achieve confinement within a 0.5 mT stray magnetic field at 2.5/4 m radial/axial positions and 12.1 ppm field inhomogeneity over a 45 mm diameter of spherical volume. The magnet is conductively refrigerated using a two-stage Gifford–McMahon cryocooler and can be maintained at a steady temperature below 5.7 K during MRI scanning. The MRI scanner assembled with the designed cryogen-free magnet demonstrated stable performance and provided MRI images with good quality and high contrast.