Method and Apparatus for Compensating for B1 Inhomogeneity in Magnetic Resonance Imaging by Nonselective Tailored RF Pulses

摘要

A method of exciting nuclear spins in a body, the method comprising the steps of: (a) immerging said body (PB) in a static magnetic field (B₀) for aligning nuclear spins along a magnetization axis (z), said static magnetic field being substantially uniform over at least a volume of interest (VOI) of said body; (b) exposing said body, or at least said volume of interest, to a time-varying magnetic field gradient having components (G_x, G_y, G_z) directed along at least three non-coplanar directions (x, y, z) and to a transverse radio-frequency field (B₁), whereby said time-varying magnetic field gradient defines a three-dimensional trajectory in k-space constituted by segments linking discrete points (k_T¹−k_T⁹), and said transverse radio-frequency field deposits radio-frequency energy along at least part of said trajectory for flipping said nuclear spins by a same predetermined flip angle, independently from their position within said volume of interest. A method of performing magnetic resonance imaging comprising a step of exciting nuclear spins in a body to be imaged, characterized in that said step is performed by carrying out a method. A magnetic resonance imaging scanner for carrying out such a method.