Patent ID: 6528999
Filing Date: 2003-03-04
Classification: G01R

Abstract:
A method of correcting linear magnetic field inhomogeneities of a nearly homogeneous magnetic field B0 in the investigation volume of a magnetic resonance apparatus, wherein magnetic resonance is excited in a sample located in the investigation volume via a radio frequency pulse, at least one additional linear magnetic gradient field is applied, and a magnetic resonance signal is measured, the method comprising the steps of:a) irradiating an excitation radio frequency pulse into the sample; b) applying a phase gradient in a predetermined direction x; c) measuring, without application of a read gradient and at a fixed time after said excitation radio frequency pulse, a single point magnetic resonance signal from the sample; d) digitizing and storing said single point magnetic resonance signal measured in step c); e) repeating steps a) through d) a plurality of times with systematic modification of a strength of said phase gradient; f) comparing said single point magnetic resonance signals to determine a maximum value, said maximum value being associated with a specific strength of said phase gradient; g) determining a linear correction gradient magnetic field for said predetermined direction from said specific strength of said phase gradient; and h) applying said linear correction gradient magnetic field of step g) in subsequent measurements of magnetic resonance in the apparatus to render the magnetic field B0 in the investigation volume homogeneous.