US 2010/0141253 A1 · MAGNETIC RESONANCE IMAGING APPARATUS

Abstract

An MRI apparatus includes an imaging means being provided with a means for generating magnetic fields respectively of a static magnetic field, a gradient magnetic field, and an RF magnetic field, and a means for receiving an echo signal generated from a subject, the imaging means being for measuring echo data associated with at least one measurement trajectory in k-space, while varying angles with respect to a coordinate axis in the k-space of the measurement trajectory, so as to collect at least one measured data for each of the angles; and an image reconstruction means for rearranging the measured data in the k-space and reconstructing an image; wherein, the image reconstruction means calculates a phase for correction based on standard data selected from the measured data for each of the angles, prior to rearranging the measured data in the k-space, and performs a phase correction as to the measured data, by using the phase for correction being calculated. With the procedure above, it is possible to reduce an artifact caused by the nonlinearity of the gradient magnetic field and/or inhomogeneities of the magnetic field, without extending the imaging time.

Claims18

Dependent claims

A magnetic resonance imaging apparatus comprising;

an imaging means comprising a means for generating magnetic fields respectively of a static magnetic field, a gradient magnetic field, and an RF magnetic field, and a means for, receiving an echo signal generated from a subject, the imaging means being for measuring echo data associated with at least one measurement trajectory in k-space, while varying angles of the measurement trajectory with respect to a coordinate axis in the k-space, so as to collect at least one measured data for each of the angles;
and
an image reconstruction means for rearranging the measured data in the k-space and reconstructing an image;
wherein,
the image reconstruction means further comprises a phase correction means for calculating a phase for correction based on standard data selected from the measured data for each of the angles, prior to rearranging the measured data in the k-space, and for performing a phase correction on the measured data, by using the calculated phase for correction.

2 more elements

An image reconstruction method for applying a gradient magnetic field and an RF magnetic field to a subject placed in a static magnetic field, in accordance with a predetermined pulse sequence, and reconstructing an image of the subject, by using data radially measured while varying angles with respect to a coordinate axis in k-space, comprising the following:

a step for executing, for measured data as to each angle, the processing of
(1) subjecting one or multiple measured data measured at an identical angle to one-dimensional Fourier transform,
(2) selecting at least one standard data from one or multiple measured data after the Fourier transform is performed,
(3) creating a phase for correction from the standard data being selected,
(4) correcting one or multiple measured data that is measured at the identical angle, by using the phase for correction, and
(5) subjecting one or multiple measured data having been corrected to one-dimensional inverse Fourier transform,
a step of rearranging the data on lattice points in the k-space, by interpolation using the measured data of each angle after the one-dimensional inverse Fourier transform is performed, and
a step of reconstructing an image by the Fourier transform, from the data rearranged in the k-space.

5 more elements

Dependencies are inferred from the claim text.

Magnetic resonance imaging apparatus

Life of this patent

Magnetic resonance imaging apparatus

Life of this patent

Abstract

Claims18