METHOD AND MRI DEVICE FOR CORRECTING DISTORTION IN AN EPI IMAGE

摘要

PURPOSE: An EPI(Echo Planar Imaging) image distortion correcting method and an MRI(Magnetic Resonance Imaging) device using the same are provided to effectively correct image distortion using a selective PSF(Point Spread Function) mapping method in an EPI image obtained by using an EPI technique in the MRI device. CONSTITUTION: An MRI device(100) includes a driving unit, a coil unit(110), and a data processing unit(160). The driving unit generates a predetermined EPI pulse sequence. The coil unit includes multiple coils. The data processing unit forms EPI image data based on a first magnetic resonance signal induced in the coil unit. The driving unit further generates a predetermined PSF pulse sequence. The coil unit generates second magnetic field in an object in response to the PSF pulse sequence from the driving unit in case the object is positioned near the coil unit. The data processing unit further forms 3D PSF image data based on a second magnetic resonance signal. The data processing unit includes a first processing unit, a second processing unit and a third processing unit. The first processing unit perpendicularly arranged to one of axes by the integral calculus of the 3D PSF image data in one axis direction of the axes obtains multiple 2D PSF data sets corresponding to each of multiple planes of image distorted axis and image undistorted axis. The second processing unit selectively obtains a PSF movement mapping map according to an inclined angle of a line pattern consisting of multiple pixels in each of the second PSF data sets. The third processing unit corrects the distortion of the EPI image data using the PSF movement mapping map. [Reference numerals] (120) RF driving unit; (130) Gradient driving unit; (140) Control unit; (150) Data acquisition unit; (160) Data processing unit; (170) Display unit