US 2017/0365076 A1Published application

Virtual projection image method

AssigneeCarestream Health, Inc.

InventorsLawrence A. Ray, Richard A. Simon, Levon O. Vogelsang

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Abstract

A method of generating a synthesized digital projection image, executed at least in part by a computer, acquires x-ray projection images at corresponding acquisition angles, and reconstructs a first volume image. Forward projection generates a preceding forward projection image at a first acquisition angle; a following forward projection image at an adjacent second acquisition angle; and an intermediate forward projection image for an intermediate angle. A synthesized projection image is formed by identifying a candidate patch of pixels from the intermediate forward projection image, matching a first patch of pixels from the preceding forward projection image and identifying a corresponding first acquired patch of pixels from the first acquired x-ray projection image, matching a second patch of pixels from the following forward projection image and matching a second acquired patch of pixels from the forward projection image. The first and second acquired patches are combined.

Claims15

Dependent claims

A method of generating a synthesized digital projection image, the method executed at least in part by a computer, the method comprising:

a) acquiring a plurality of x-ray projection images, wherein each of the x-ray projection images has a corresponding acquisition angle;
b) reconstructing a first volume image using the plurality of acquired x-ray projection images;
c) performing a forward projection using the first reconstructed volume image that generates at least the following:
(i) a preceding forward projection image that corresponds to a first acquired x-ray projection image at a first acquisition angle;
(ii) a following forward projection image that corresponds to a second acquired x-ray projection image at a second acquisition angle that is adjacent the first acquisition angle;
and
(iii) an intermediate forward projection image that corresponds to an intermediate angle that lies between the first acquisition angle and second acquisition angle;
d) forming the synthesized projection image by a repeated sequence of:
(i) identifying a candidate patch of pixels from within the intermediate forward projection image;
(ii) identifying a first patch of pixels from the preceding forward projection image that closely matches the candidate patch of pixels and identifying a first acquired patch of pixels from the first acquired x-ray projection image that corresponds to the first patch of pixels from the preceding forward projection image;
(iii) identifying a second patch of pixels from the following forward projection image that closely matches the candidate patch of pixels and identifying a second acquired patch of pixels from the second acquired x-ray projection image that corresponds to the second patch of pixels from the following forward projection image;
and
(iv) combining the first acquired patch of pixels identified from step d)(ii) and the second acquired patch of pixels identified from step d)(iii) to form a replacement patch of pixels and replacing the candidate patch of pixels from within the intermediate forward projection image with the replacement patch of pixels;
e) repeating step c) to generate a first set of a plurality of intermediate forward projection images, wherein each member of the first set is at an angle between two adjacent acquisition angles of the plurality of acquired x-ray projection images;
f) repeating step d) to generate each member of a second set of a plurality of synthesized projection images from the first set of intermediate forward projection images;
g) reconstructing a second volume image using the plurality of acquired x-ray projection images and the second set of synthesized projection images;
and
h) generating and displaying a rendered 2-D image from the reconstructed second volume image.

15 more elements

A method of generating a synthesized digital projection image, the method executed at least in part by a computer, the method comprising:

a) obtaining a first ordered set of acquired x-ray projection images, wherein the ordering of the first ordered set is according to an acquisition angle for each acquired projection image;
b) reconstructing a first volume image using the first ordered set of acquired x-ray projection images;
c) performing a forward projection using the first reconstructed volume image that generates at least the following:
(i) a preceding forward projection image that corresponds to a first acquired projection image from the first ordered set at a first acquisition angle;
(ii) a following forward projection image that corresponds to a second acquired projection image from the first ordered set at a second acquisition angle that is adjacent the first acquisition angle;
and
(iii) an intermediate forward projection image that corresponds to an intermediate angle that lies between the first acquisition angle and second acquisition angle;
d) forming the synthesized projection image by a repeated sequence of:
(i) identifying a candidate patch of pixels from within the intermediate forward projection image;
(ii) identifying a first patch of pixels from the preceding forward projection image that closely matches the candidate patch of pixels and identifying a first acquired patch of pixels from the first acquired projection image that corresponds to the first patch of pixels from the preceding forward projection image;
(iii) identifying a second patch of pixels from the following forward projection image that closely matches the candidate patch of pixels and identifying a second acquired patch of pixels from the second acquired projection image that corresponds to the second patch of pixels from the following forward projection image;
and
(iv) combining the first acquired patch of pixels identified from step d)(ii) and the second acquired patch of pixels identified from step d)(iii) to form a replacement patch of pixels and replacing the candidate patch of pixels from within the intermediate forward projection image with the replacement patch of pixels;
and
e) storing, transmitting, or displaying the synthesized projection image.

12 more elements

A method of generating an interpolated projection image, the method executed at least in part by a computer and comprising:

a) accessing a volume image generated using a plurality of projection images;
b) generating a left, right, and middle forward-projected image using forward projection through the volume, the left, right, and middle forward-projected images each comprised of a plurality of pixels wherein each of the plurality of pixels has a value that is indicative of material density;
c) repeating the sequence of:
1) identifying a first region of interest in the middle image, the first region of interest defined by a first plurality of pixels;
2) determining a second region of interest in the right image corresponding to the first region of interest in the middle image, the second region of interest defined by a second plurality of pixels;
3) determining a third region of interest in the left image corresponding to the first region of interest in the left image, the third region of interest defined by a third plurality of pixels;
and
4) forming the interpolated projection image, by, for each pixel in the first region of interest:
i) using a comparison metric, comparing the pixel to the second and third plurality of pixels;
ii) selecting one pixel from each of the second and third plurality of pixels in accordance with the comparison metric;
iii) forming a replacement pixel using the two selected pixels;
iv) identifying a candidate pixel in the interpolated image corresponding with the pixel;
and
v) replacing the candidate pixel with the replacement pixel;
and
d) displaying, storing, or transmitting the formed interpolated projection image.

13 more elements

Dependencies are inferred from the claim text.