title: Echo-Planar Imaging for a 9.4 Tesla Vertical-Bore Superconducting Magnet Using an Unshielded Gradient Coil.
abstract: Echo-planar imaging (EPI) sequences were developed for a 9.4 Tesla vertical standard bore (~54 mm) superconducting magnet using an unshielded gradient coil optimized for live mice imaging and a data correction technique with reference scans. Because EPI requires fast switching of intense magnetic field gradients, eddy currents were induced in the surrounding metallic materials, e.g., the room temperature bore, and this produced serious artifacts on the EPI images. We solved the problem using an unshielded gradient coil set of proper size (outer diameter = 39 mm, inner diameter = 32 mm) with time control of the current rise and reference scans. The obtained EPI images of a phantom and a plant sample were almost artifact-free and demonstrated the promise of our approach.
authors.affiliation: Institute of Applied Physics, University of Tsukuba.
authors.forename: Nao
authors.initials: N
authors.lastname: Kodama
authors.forename: Katsumi
authors.initials: K
authors.lastname: Kose
mesh_terms: D000818:Animals; D000077102:Apium; D016477:Artifacts; D017352:Echo-Planar Imaging / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D007091:Image Processing, Computer-Assisted / Q000379:methods; D060526:Magnetic Fields; D059346:Magnets; D008670:Metals; D051379:Mice; D019047:Phantoms, Imaging; D000072176:Superconductivity; D013696:Temperature; D013997:Time Factors
chemical_list: D008670:Metals