title: An algorithm to calculate the NMR signal of a multi spin-echo sequence with relaxation and spin-diffusion.
abstract: An algorithm to calculate NMR signals of a multi-echo pulse sequence with arbitrary position dependent B0 and B1 fields taking into account relaxation and spin-diffusion is presented. The multi-echo pulse sequence consists of an initial RF pulse ("90 degrees " RF pulse) and a series of L refocusing RF pulses with arbitrary phases and flip-angles. The calculation is exact and takes into account all the magnetization pathways that contribute to the signal on a predefined spatial grid. The theoretical prediction is verified experimentally using a high field NMR microscopy system. The algorithm was implemented in a simulation program in order to optimize the design of an inside-out MR intra-vascular catheter that is used for characterization of vessel wall tissue. Measured data obtained with the catheter are in good agreement with the theoretical prediction of the simulation.
authors.affiliation: TopSpin Medical (Israel) Ltd. Global Park, 2 Yodfat Street, North Industrial Zone, Lod 71291, Israel. zursy@netvision.net.il
authors.forename: Yuval
authors.initials: Y
authors.lastname: Zur
mesh_terms: D000465:Algorithms; D002404:Catheterization; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water