Design and Construction of an Optimized Open-Access Human-Scale MRI Magnet for Posture Dependent Lung Studies
Walsworth R, Rosen M, Mair R, Tsai L
Harvard-Smithsonian Center for Astrophysics, Harvard University
We have built an optimized low-field open-access MRI system specifically designed for orientation-dependent pulmonary 3He human imaging. A B0 homogeneity under 40 Hz across a 35 cm DSV at 5 mT, combined with effective noise filtering, allowed high sensitivity 1H and 3He NMR and MRI at 5 mT. The MRI system has more than one order-of-magnitude improvement in B0 and noise suppression over a previous engineering prototype system, and optimized planar gradient coils have shortened imaging times. These improvements allow us to achieve a target of 2 x 2 x 20 mm resolution for rapid 3He imaging.