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US 2009/0022266 A1Published application
Motion correction for ct using marker projections
AssigneeXoran Technologies, Inc.
InventorsJoseph Webster Stayman, Matt Jacobson
Life of this patent
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Abstract
A method of correcting for motion of a patient during a CT scan includes observing positions of radio-opaque markers in a series of two dimensional x-ray projections taken by a scanner. The markers are positioned on a patient in a fixed and rigid relationship, a CT scan is performed to obtain a three dimensional CT image, and an actual projected position of each of the markers in each two dimensional projection is determined. A motion data set is obtained based on the actual projected positions of the plurality of the markers. A final three dimensional CT image is reconstructed employing the motion data set.
Claims31
A method of correcting for motion of a patient during a CT scan, the method comprising the steps of:
- a) positioning a plurality of radio-dense or radio-opaque markers on a patient;
- b) measuring actual projected positions of the plurality of markers in each two dimensional x-ray projection collected by a CT scanner;
- c) obtaining a motion data set based on measurements obtained in said step b);
- and
- d) reconstructing a final three dimensional CT image employing the motion data set.
2 more elements
A method of correcting for motion of a patient during a CT scan, the method comprising the steps of:
- a) positioning a plurality of radio-dense or radio-opaque markers on a patient;
- b) obtaining a plurality of two dimensional x-ray projections of the patient;
- c) generating a three dimensional CT image from the plurality of two dimensional x-ray projections;
- d) determining a location of each of the plurality of markers in the three dimensional CT image;
- e) deleting the plurality of markers from the three dimensional CT image to generate a new three dimensional CT image;
- f) generating a set of simulated two dimensional x-ray projections from the new three dimensional CT image;
- g) subtracting the set of simulated two dimensional x-ray projections from the plurality of two dimensional x-ray projections to produce a new set of two dimensional x-ray projections showing the plurality of markers;
- h) determining an actual projected position of each of the plurality of markers in the new set of two dimensional x-ray projections;
- i) obtaining a motion data set based on a known spacing and an orientation of the plurality of markers and the actual projected position of each of the plurality of the markers;
- and
- j) reconstructing a final three dimensional CT image employing the motion data set.
8 more elements
A method of correcting for motion of a patient during a CT scan, the method comprising the steps of:
- a) positioning a plurality of radio-dense or radio-opaque markers on a patient;
- b) deriving a three dimensional CT image from two dimensional x-ray projections collected during a CT scan;
- c) employing the three dimensional CT image to determine an actual position of each of the plurality of markers in each two dimensional x-ray projection of the patient;
- d) obtaining a motion data set based on the actual position of the plurality of the markers in each two dimensional x-ray projection;
- and
- e) reconstructing a final three dimensional CT image employing the motion data set.
3 more elements
A CT scanner comprising:
- a gantry including a first arm and a second arm;
- an x-ray source that generates x-rays, wherein one of the first arm and the second arm houses the x-ray source;
- a detector that converts the x-rays to a plurality of two dimensional x-ray projections, wherein the detector is housed in the other of the first arm and the second arm;
- and
- a computer for correcting for motion of a patient during a CT scan, wherein the computer generates a three dimensional CT image from the plurality of two dimensional x-ray projections, determines an actual projected position of each of a plurality of markers positioned on the patient, obtains a motion data set based on the actual projected positions of the plurality of the markers, and reconstructs a final three dimensional CT image employing the motion data set.
2 more elements
A CT scanner comprising:
- a gantry including a first arm and a second arm;
- an x-ray source that generates x-rays, wherein one of the first arm and the second arm houses the x-ray source;
- a detector that converts the x-rays to a plurality of two dimensional x-ray projections, wherein the detector is housed in the other of the first arm and the second arm;
- and
- a computer for correcting for motion of a patient during a CT scan, wherein the computer generates a three dimensional CT image from the plurality of two dimensional x-ray projections, determines a location of each of a plurality of markers in the three dimensional CT image, deletes the plurality of markers from the three dimensional CT image to generate a new three dimensional CT image, generates a set of simulated two dimensional x-ray projections from the new three dimensional CT image, subtracts the set of simulated two dimensional x-ray projections from the two dimensional x-ray projections to produce a new set of two dimensional x-ray projections showing the plurality of markers, determines an actual projected position of each of the plurality of markers in the new set of two dimensional x-ray projections, obtains a motion data set based on the actual projected positions of the plurality of the markers, and reconstructs a final three dimensional CT image employing the motion data set.
2 more elements
Dependencies are inferred from the claim text.