Method and system of MR imaging with reduced radial ripple artifacts
AssigneeGeneral Electric Company
InventorsAjeetkumar Gaddipati, Robert Donald Peters, Michael R. Hartley
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Abstract
A method and system of MR imaging is disclosed that enables PROPELLER imaging to be feasibly carried out independently of slice orientation or anatomy of interest. The invention is directed to the acquisition of blades of MR data that are rotated about a central region of k-space and reconstructing an image of arbitrary slice orientation from the blades of MR data that is substantially absent of radial ripple artifacts caused by phase aliasing from tissue outside the field of view in the slice plane.
Claims20
An MR imaging apparatus comprising:
- a plurality of gradient coils positioned about a bore of a magnet to impress a polarizing magnetic field and an RF transceiver system and an RF switch controlled by a pulse module to transmit RF signals to an RF coil assembly to acquire MR images;
- and
- a computer programmed to:
- acquire blades of MR data from an FOV along any slice orientation;
- fill k-space with the blades of MR data such that adjacent blades are rotated from one another;
- transform the k-space to image space;
- and
- reconstruct an image substantially free of radial ripple artifacts from the image space.
A method MR data acquisition comprising the steps of:
- exciting an echo train to sample for MR data acquisition from an FOV;
- sampling the echo train to partially fill a k-space blade of a plurality of k-space data lines extending through a central region of k-space;
- filling a remainder of the partially filled k-space blade with data determined from that sampled from the echo train;
- and
- repeating the exciting, the sampling, and the filling steps until a plurality of k-space blades have been filled to fill k-space, each k-space blade extending through the central region of k-space and adjacent k-space blades being rotated from one another about the central region of k-space.
A computer readable storage medium having a computer program stored thereon and representing a set of instructions that when executed by a computer causes the computer to:
- acquire a plurality of blades of k-space from an object having a portion thereof extending beyond an FOV;
- image the blades of k-space;
- isolate a blade image describing a central portion of the FOV in a phase encoding direction;
- crop the blade image to remove data from phase encode locations outside the central portion of the FOV in the phase encoding direction;
- transform the cropped blade image to a cropped blade of k-space;
- and
- replace the blade of k-space corresponding to the isolated blade image with the cropped blade of k-space.
Dependencies are inferred from the claim text.