Patent ID: 6489770
Filing Date: 2002-12-03
Classification: G01R

Abstract:
A nuclear magnetic resonance imaging apparatus comprising:a static magnetic field generating means for generating a static magnetic field to be applied to an object; a skimming magnetic field generating means for generating shimming magnetic fields or a plurality of channels for adjusting a homogeneity of said static magnetic field; a gradient magnetic field generating means for generating gradient magnetic fields for applying to said object in a first, second and third directions which are in different direction each other; a radio frequency pulse generating means for generating a radio frequency pulse for applying to said object; a signal detecting means for detecting magnetic resonance signals generated from said object; a processing means for processing said magnetic resonance signals detected by said signal detecting means; a pulse sequence controlling means for controlling said shimming magnetic field generating means, said gradient magnetic field generating means, said radio-frequency pulse generating means and said signal detecting means, and defining a pulse sequence; and an adjusting means for adjusting a homogeneity of said static magnetic field by controlling said shimming magnetic field generating means and/or said gradient magnetic field; wherein said pulse sequence controlling means effects a pulse sequence of a multi-gradient system and an adjusting pulse sequence control for adjusting said homogeneity of said static magnetic field by detecting said magnetic resonance signals in a state where said gradient magnetic field in at least one direction is applied to said object inverting periodically a polarity of gradient of said gradient magnetic field; wherein said processing means determines a magnetic resonance spectrum from said magnetic resonance signals detected in said adjusting pulse sequence control by division of signals of said magnetic resonance signals into signals of odd number and signals of even number with rearrangement thereof, and extracts a peak corresponding to a specific nucleus, in said magnetic resonance spectrum, and calculates a width of said peak; and wherein said adjusting means adjusts said homogeneity of said static magnetic field such that said width of said peak become narrow.