Geometric distortion correction in magnetic resonance imaging
AssigneeCase Western Reserve University
InventorsDavid Dean, Jeffrey L. Duerk, Janardhan K. Kamath
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Abstract
A three dimensional (3D) magnetic resonance imaging (MRI) system (100) performs object-induced geometric distortion correction. The MRI system performs (202) a 3D MRI pulse sequence to acquire a first 3D MR image of an examination region containing at least a portion of a subject and performs (202) the 3D MRI pulse sequence a second time to acquire a second 3D MR image of the examination region A computer system (110) computes (210) a voxel error map based on a phase difference between the first and second 3D MR images and corrects (212) voxel positions in one of the 3D MR images in accordance with the voxel error map.
Claims15
A method for correcting object-induced distortion in a three dimensional (3D) magnetic resonance (MR) image in a 3D magnetic resonance imaging (MRI) system, the method comprising the steps of:
- (a) performing a 3D MRI pulse sequence to acquire a first 3D MR image of an examination region containing at least a portion of a subject;
- (b) performing the 3D MRI pulse sequence a second time to acquire a second 3D MR image of the examination region;
- (c) computing a voxel error map based on a phase difference between the first and second 3D MR images;
- and
- (d) correcting voxel positions in one of the 3D MR images in accordance with the voxel error map to correct object-induced distortion due to the varying magnetic susceptibility of the subject.
A three-dimensional (3D) magnetic resonance imaging (MRI) system comprising:
- (a) 3D MRI means for performing a 3D MRI pulse sequence to acquire a first 3D MR image of an examination region containing at least a portion of a subject and for performing the 3D MRI pulse sequence a second time to acquire a second 3D MR image of the examination region;
- (b) means for computing a voxel error map based on a phase difference between the first and second 3D MR images;
- and
- (c) means for correcting voxel positions in one of the 3D MR images in accordance with the voxel error map to correct objected-induced distortion due to the varying magnetic susceptibility of the subject.
A three dimensional (3D) magnetic resonance imaging (MRI) system comprising:
- a static magnet for producing a magnetic field along a predetermined axis relative to at least a portion of a subject in an examination region;
- pulse sequence apparatus for creating magnetic field gradients in the examination region, for applying radio frequency (RF) pulsed magnetic fields in the examination region, and for receiving RF magnetic resonance (MR) signals from the examination region;
- pulse sequence control apparatus for controlling the pulse sequence apparatus to apply a 3D MRI pulse sequence in the examination region a first time and to apply the 3D MRI pulse sequence in the examination region a second time;
- and
- a computer system for acquiring a first 3D MR image from received RF MR signals resulting from the first time application of the 3D MRI pulse sequence in the examination region, for acquiring a second 3D MR image from received RF MR signals resulting from the second time application of the 3D MRI pulse sequence, for computing a voxel error map based on a phase difference between the first and second 3D MR images, and for correcting voxel positions in one of the 3D MR images in accordance with the voxel error map to correct objected-induced distortion due to the varying magnetic susceptibility of the subject.
Dependencies are inferred from the claim text.