Method and apparatus for 3D metal and high-density artifact correction for cone-beam and fan-beam CT imaging

• US 8,229,246 B2
• Filed: 09/19/2011
• Issued: 07/24/2012
• Est. Priority Date: 03/10/2008
• Status: Active Grant

• Current Assignee: University of Rochester
• Original Assignee: University of Rochester
• Inventors: Ning, Ruola, Zhang, Yan
• Primary Examiner(s): Lu, Tom Y
• Application Number:
  US13/236,289
• Publication Number:
  US 20120008845A1
• Time in Patent Office: 309 Days
• Field of Search: 382/128, 382/131, 382/275
• US Class Current: 382/275
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4085 Cone-beams
• CPC Class Codes: A61B 6/4233 using matrix detectors
• CPC Class Codes: A61B 6/488 involving pre-scan acquisition
• CPC Class Codes: A61B 6/505 for diagnosis of bone
• CPC Class Codes: A61B 6/5205 involving processing of raw data to produce diagnostic data
• CPC Class Codes: A61B 6/5258 involving detection or reduction of artifacts or noise
• CPC Class Codes: A61B 6/563 involving image data transmission via a network
• CPC Class Codes: G06T 11/005 Specific pre-processing for tomographic reconstruction, e.g. calibration, source positioning, rebinning, scatter correction, retrospective gating
• CPC Class Codes: G06T 2207/10081 Computed x-ray tomography [CT]
• CPC Class Codes: G06T 2207/20128 Atlas-based segmentation
• CPC Class Codes: G06T 2207/30008 Bone
• CPC Class Codes: G06T 2207/30052 Implant; Prosthesis
• CPC Class Codes: G06T 7/12 Edge-based segmentation
• CPC Class Codes: G06T 7/149 involving deformable models, e.g. active contour models

Abstract

A 3D metal artifacts correction technique corrects the streaking artifacts generated by titanium implants or other similar objects. A cone-beam computed tomography system is utilized to provide 3D images. A priori information (such as the shape information and the CT value) of high density sub-objects is acquired and used for later artifacts correction. An optimization process with iterations is applied to minimize the error and result in accurate reconstruction images of the object.

Claims

1. A method for producing an image of a region of interest while correcting artifacts caused by sub-objects within the region of interest, the method comprising:

(a) receiving three-dimensional image data of the region of interest;

(b) receiving a library of shape information and imaging characteristics of the sub-objects;

(c) using the three-dimensional image data and the library to produce images of the sub-objects in the region of interest;

(d) using an optimization process to produce segmented images of the sub-objects in the region of interest;

(e) using the segmented images to produce error projections; and

(f) using the error projections to produce the projection images of the region of interest such that the artifacts are corrected in the image;

(g) performing a tomographically reconstructed image of the region of interest from the corrected projection images.

2. The method of claim 1, wherein the three-dimensional image data comprise computed tomography image data.

3. The method of claim 2, wherein the computed tomography image data are cone-beam or fan-beam computed tomography image data.

4. The method of claim 1, wherein step (a) comprises taking the three-dimensional image data.

5. The method of claim 1, wherein step (a) comprises receiving the three-dimensional image data previously formed on a storage medium or over a communication medium.

6. The method of claim 1, wherein step (b) comprises receiving the library previously formed on a storage medium.

7. The method of claim 1, wherein step (b) comprises forming the library through scanning, reconstruction and information extraction performed on the sub-objects.

8. The method of claim 1, wherein step (e) comprises determining an amount of beam hardening caused by the sub-objects.

9. The method of claim 8, wherein step (e) further comprises calculating a polynomial function of a line integral of the beam hardening.

10. The method of claim 1, wherein the sub-objects comprise metal objects causing metal artifacts in the images.

11. The method of claim 1, wherein the optimization process is iterative.

12. A system for producing an image of a region of interest while correcting artifacts caused by sub-objects within the region of interest, the system comprising:

a device for receiving three-dimensional image data of the region of interest;

a device for receiving a library of shape information and imaging characteristics of the sub-objects;

a processor, having access to the three-dimensional image data and the library, the processor being configured for;

(i) using the three-dimensional image data and the library to produce images of the sub-objects in the region of interest;

(ii) performing an optimization process to produce segmented images of the sub-objects in the region of interest;

(iii) using the segmented images to produce error projections; and

(iv) using the error projections to produce the projection images of the region of interest such that the artifacts are corrected in the projection images; and

(v) obtaining tomographically-reconstructed image of the region of interest from the corrected projection images

an output for outputting the reconstructed image of the region of interest.

13. The system of claim 12, wherein the processor is configured such that the three-dimensional image data comprise computed tomography image data.

14. The system of claim 13, wherein the processor is configured such that the computed tomography image data are cone-beam or fan-beam computed tomography image data.

15. The system of claim 12, wherein the device for receiving the three-dimensional image data comprises a device for taking the three-dimensional image data.

16. The system of claim 12, wherein the device for receiving the three-dimensional image data comprises a device for receiving the three-dimensional image data previously formed on a storage medium or over a communication medium.

17. The system of claim 12, wherein the device for receiving the library comprises a device for receiving the library previously formed and provided on a storage medium.

18. The system of claim 14, wherein the processor is configured to determine an amount of beam hardening caused by the sub-objects.

19. The system of claim 18, wherein the processor is further configured to calculate a polynomial function of a line integral of the beam hardening.