Method of reconstruction of a three-dimensional image of an object

• US 6,320,928 B1
• Filed: 03/01/1999
• Issued: 11/20/2001
• Est. Priority Date: 09/04/1996
• Status: Expired due to Fees

• Current Assignee: GE Medical Systems Norway AS (General Electric Company)
• Original Assignee: GE Medical Systems Norway AS (General Electric Company)
• Inventors: Boucherie, Romain, Trousset, Yves, Vaillant, Régis, Romeas, René
• Primary Examiner(s): Grant, William
• Assistant Examiner(s): CABRERA, ZOILA E
• Application Number:
  US09/254,094
• Time in Patent Office: 995 Days
• Field of Search: 700/98, 700/118, 700/182, 700/120, 345/419, 345/420, 382/133, 382/130, 378/4, 378/901
• US Class Current: 378/4
• CPC Class Codes: A61B 6/583 using calibration phantoms
• CPC Class Codes: G06T 11/006 Inverse problem, transformation from projection-space into object-space, e.g. transform methods, back-projection, algebraic methods
• CPC Class Codes: G06T 2211/404 Angiography
• CPC Class Codes: G06T 2211/424 Iterative

Abstract

A set of digital two-dimensional projected images of an object is acquired for different positions of a camera rotating around an object. The projected images are calibrated into a volume containing the object and divided into voxels, the space coordinates of which are identified in a chosen calibration frame of reference. A pretreatment is applied on each acquired image in order to elaborate a rectified image having a predetermined spatial orientation selected as a function of a chosen specific axis of the calibration frame of reference, and an iterative algorithm of algebraic image reconstruction between each rectified image and the set of voxels is applied by successively treating the voxels in a predetermined order linked to the choice of said specific axis, which makes it possible to minimize the duration of reconstruction of the three-dimensional image.

Claims

1. Method of reconstruction of a three-dimensional image of an object from a set of digital two-dimensional projected images of the object obtained for different positions around the object, comprising the steps of:

a. acquiring the set of digital two-dimensional projected images and a reconstruction of the three-dimensional image from the projected two-dimensional acquired images and an iterative algorithm of algebraic image reconstruction;

b. calibrating the different position images for a volume containing the object and dividing into voxels, the space coordinates of which are identified in a chosen calibration frame of reference;

c. applying a pretreatment on each acquired image in order to establish a rectified image having a predetermined spatial orientation selected as a function of a chosen specific axis of the calibration frame of reference; and

d. applying the iterative algorithm of algebraic image reconstruction between each rectified image and the set of voxels by successively treating the voxels in a predetermined order linked to the choice of said specific axis, whereby a duration of reconstruction of the three-dimensional image is minimized.

2. Method according to claim 1, wherein the digital two-dimensional projected images are acquired from detectors placed in different projection planes corresponding to the different positions;

the calibration provides calibration parameters relative to the projection of voxels in the projection planes;

in the pretreatment of each acquired two-dimensional image, the acquired two-dimensional image is projected in a rectified plane parallel to the specific axis chosen, a rectified frame of reference is defined in that rectified plane, one of the axes of which is parallel to the specific axis chosen, and rectification parameters are elaborated, making it possible to determine the coordinates of each pixel of the acquired image in the associated rectified frame of reference, in order to elaborate the digital rectified image for the acquired image, and the calibration parameters associated with each acquired image are modified, taking into account the rectification parameters, and applying the iterative algorithm of algebraic image reconstruction between each rectified image and the set of voxels, taking into account the modified calibration parameters by successively treating the voxels situated on lines parallel to said specific axis chosen.

3. Method according to claim 2, wherein an optical axis of each acquired image being determined on calibration, the rectified plane of an acquired image is determined as being the plane perpendicular to the projection of the optical axis of that acquired image in the plane perpendicular to the specific axis chosen.

4. Method according to claim 1 wherein the different projected images are obtained by a camera rotating around the object, calibration of the camera determines a mean estimated axis of rotation of the camera, and the mean estimated axis of rotation is chosen as specific axis of the calibration frame of reference.

5. Method according to claim 2 wherein the different projected images are obtained by a camera rotating around the object, calibration of the camera determines a mean estimated axis of rotation of the camera, and the mean estimated axis of rotation is chosen as specific axis of the calibration frame of reference.

6. Method according to claim 3 wherein the different projected images are obtained by a camera rotating around the object, calibration of the camera determines a mean estimated axis of rotation of the camera, and the mean estimated axis of rotation is chosen as specific axis of the calibration frame of reference.

7. Method according to claim 1 wherein the acquisition of each two-dimensional projected image entails a difference of two images of the object obtained before and after injection of a contrast product in the object, for a same position of the projected images.

8. Method according to claim 2 wherein the acquisition of each two-dimensional projected image entails a difference of two images of the object obtained before and after injection of a contrast product in the object, for a same position of the projected images.

9. Method according to claim 3 wherein the acquisition of each two-dimensional projected image entails a difference of two images of the object obtained before and after injection of a contrast product in the object, for a same position of the projected images.

10. Method according to claim 4 wherein the acquisition of each two-dimensional projected image entails a difference of two images of the object obtained before and after injection of a contrast product in the object, for a same position of the projected images.

11. Method according to claim 5 wherein the acquisition of each two-dimensional projected image entails a difference of two images of the object obtained before and after injection of a contrast product in the object, for a same position of the projected images.

12. Method according to claim 6 wherein the acquisition of each two-dimensional projected image entails a difference of two images of the object obtained before and after injection of a contrast product in the object, for a same position of the projected images.