4647858 Methods for overcoming transient magnetic field inhomogeneity in nuclear magnetic resonance imaging

Abstract

Methods for overcoming transient magnetic field gradient inhomogeneity in a nuclear magnetic resonance imaging and/or nuclear magnetic resonance spectroscopic imaging system, wherein the inhomogeneities are induced by the pulsed magnetic field gradients utilized in the imaging process itself, provide at least one correction pulse signal during, or after, any application of the desired magnetic field to the sample-to-be-investigated in the system. At least one of the pulse signal characteristics is adjusted to oppose and substantially cancel an error-producing portion of the total magnetic field gradient in a particular direction. The magnetic field gradient correction signal(s) can be applied: during a non-selective RF pulse; immediately subsequent to an initial gradient field application (either alone or coincident with a selective 180° RF pulse); during acquisition of response signal data; or at any time to correct for inter-gradient cross-talk conditions.