Method and apparatus for soft-tissue volume visualization

• US 6,898,263 B2
• Filed: 11/27/2002
• Issued: 05/24/2005
• Est. Priority Date: 11/27/2002
• Status: Expired due to Fees

• Current Assignee: GE Medical Systems Global Technology Company LLC (GE Healthcare Technologies, Inc.)
• Original Assignee: GE Medical Systems Global Technology Company LLC (GE Healthcare Technologies, Inc.)
• Inventors: Sabol, John Michael, Avinash, Gopal B., Walker, Matthew Joseph
• Primary Examiner(s): Bruce, David V.
• Assistant Examiner(s): Kiknadze, Irakli
• Application Number:
  US10/306,468
• Publication Number:
  US 20040101104A1
• Time in Patent Office: 909 Days
• Field of Search: 378/98.9, 378/19, 378/4, 378/901, 378/5, 378/9
• US Class Current: 378/4
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: A61B 6/4035 the source being combined with a filter or grating
• CPC Class Codes: A61B 6/405 Source units specially adapted to modify characteristics of the beam during the data acquisition process A61B6/4021, A61B6/4035 take precedence
• CPC Class Codes: A61B 6/4241 using energy resolving detectors, e.g. photon counting
• CPC Class Codes: A61B 6/463 characterised by displaying multiple images or images and diagnostic data on one display
• CPC Class Codes: A61B 6/466 adapted to display 3D data
• CPC Class Codes: A61B 6/482 involving multiple energy imaging
• CPC Class Codes: Y10S 378/901 Computer tomography program or processor

Abstract

A method for obtaining data including scanning an object using a multi-energy computed tomography (MECT) system to obtain data to generate an anatomical image, and decomposing the obtained data to generate a first density image representative of bone material and a second density image representative of soft-tissue. The method further includes segmenting at least one of the first density image and the second density image, and volume rendering the second density image.

Claims

1. A method for obtaining data, said method comprising:

scanning an object using a multi-energy computed tomography (MECT) system to obtain data to generate a computed tomographic (CT) anatomical image;

decomposing the obtained data to generate a first CT density image representative of bone material and a second CT density image representative of soft-tissue;

segmenting at least one of the first CT density image and the second CT density image; and

volume rendering the second CT density image.

2. A method in accordance with claim 1 further comprising displaying the CT anatomical image, the first CT density image, and the second CT density image on a display to facilitate surgical instrument mapping.

3. A method for obtaining data, said method comprising:

scanning an object using a multi-energy computed tomography (MECT) system to obtain data to generate an anatomical image;

decomposing the obtained data to generate a first density image representative of bone material and a second density image representative of soft-tissue;

segmenting at least one of the first density image and the second density image; and

volume rendering the second density image;

wherein segmenting at least one of the first density image and the second density image comprises;

identifying within the first density image areas smaller than a predetermined size; and

importing data into the second density image from the anatomical image according to the identified areas of the first density image.

4. A method in accordance with claim 3, wherein identifying within the first density image areas smaller than a predetermined size comprises:

thresholding the first density image to produce a first binary mask image representing bone and calcification; and

extracting areas identified as smaller than the predetermined size from the first binary mask image to produce a second binary mask image substantially representing calcification.

5. A method for obtaining data, said method comprising:

scanning an object using a multi-energy computed tomography (MECT) system to obtain data to generate an anatomical image;

decomposing the obtained data to generate a first density image representative of bone material and a second density image representative of soft-tissue;

segmenting at least one of the first density image and the second density image; and

volume rendering the second density image;

wherein scanning an object using an MECT comprises scanning the object with a high-energy projection to obtain a high-energy anatomical image and scanning the object with a low-energy projection to obtain a low-energy anatomical image, said decomposing the obtained data comprises;

using the equation $I_b=\frac{H}{L^{\mathrm{wb}}}$

to generate the first density image, wherein 0<

w_s<

w_b<

1, I_b is the first density image, H is the high-energy anatomical image, and L is the low-energy anatomical image; and

using the equation $I_s=\frac{H}{L^{w_s}}$

to generate the second density image wherein 0<

w_s<

w_b<

1, I_s is the second density image, H is the high-energy anatomical image, and L is the low-energy anatomical image.

6. A method for obtaining data, said method comprising:

scanning an object using a multi-energy computed tomography (MECT) system to obtain data to generate an anatomical image;

decomposing the obtained data to generate a first density image representative of bone material and a second density image representative of soft-tissue;

segmenting at least one of the first density image and the second density image; and

volume rendering the second density image;

wherein scanning an object using an MECT comprises scanning the object with a high-energy projection to obtain a high-energy anatomical image and scanning the object with a low-energy projection to obtain a low-energy anatomical image, said method further comprising contrast matching the second density image with the high-energy image to produce a contrast matched soft-tissue image.

7. A method in accordance with claim 6 wherein contrast matching the second density image with the high-energy image comprises using the equation $I_{\mathrm{HS}}=I_s^{\frac{w_b}{w_b-w_s}}$

LPF(Ib-wswb-ws),

wherein 0<

w_s<

w_b<

1 I_HS is the contrast matched image, I_b is the first density image, I_s is the second density image, and LPF is a low pass filter, to match a contrast of structures within the second density image with corresponding structures within the high-energy image.

8. A method in accordance with claim 6 wherein importing data into the second density image from the anatomical image according to the identified areas of the first density image comprises merging data regarding the identified areas from the high-energy image with the contrast matched soft-tissue image to produce a soft-tissue image including calcification.

9. A multi-energy computed tomography (MECT) system comprising:

at least one radiation source;

at least one radiation detector; and

a computer operationally coupled to said radiation source and said radiation detector, said computer configured to;

receive data regarding a first energy spectrum of a scan of an object;

receive data regarding a second energy spectrum of the scan of the object;

decompose said received data to generate a first density image representative of bone material and a second density image representative of soft-tissue;

identify within said first density image areas smaller than a predetermined size; and

import data into said second density image from said data regarding the first energy spectrum according to said identified areas of said first density image.

10. An MECT system in accordance with claim 9 wherein said computer configured to decompose said received data by performing at least one of a CT number difference decomposition, a Compton and photoelectric decomposition, a basis material decomposition (BMD), and a logarithm subtraction decomposition (LSD).

11. An MECT system in accordance with claim 9 wherein said computer configured to identify within said first density image areas smaller than a predetermined size by separating out high-contrast bone regions and high-contrast calcification regions from low-contrast regions.

12. An MECT system in accordance with claim 9 wherein said computer further configured to match a contrast of structures within said second density image with corresponding structures within said data regarding the first energy spectrum.

13. An MECT system in accordance with claim 9 wherein said computer further configured to:

build a three-dimensional image using said second density image including said imported data regarding said identified areas from said data regarding the first energy spectrum; and

rendering said three-dimensional image to produce a high-contrast rendered image.

14. A multi-energy computed tomography (MECT) system comprising:

at least one radiation source;

at least one radiation detector; and

a computer operationally coupled to said radiation source and said radiation detector, said computer configured to;

receive image data for an object;

decompose said received image data into a first density image representative of bone material and a second density image representative of soft-tissue;

identify within said first density image areas smaller than a predetermined size; and

extract said identified areas within said first density image using an algorithm configured to use the connectivity of binary pixels.

15. An MECT system in accordance with claim 14 wherein said computer further configured to:

threshold said first density image to produce a first binary mask image representing bone and calcification; and

extract said identified areas within said first density image from said first binary mask to produce a second binary mask image substantially representing calcification.

16. An MECT system in accordance with claim 15 wherein said computer configured to import data into said second density image from said received image data according to said identified areas in said first density image.

17. An MECT system in accordance with claim 14 wherein said computer further configured to contrast match said second density image with said received image data to produce a contrast-matched soft-tissue image.

18. An MECT system in accordance with claim 17 wherein said computer further configured to:

import data into said contrast-matched soft-tissue image from said received image data according to said identified areas of said first density image;

build a three-dimensional image using said contrast-matched soft-tissue image including said imported data; and

render said three-dimensional image using at least one of volume and surface rendering to produce a high-contrast rendered image.

19. An MECT system in accordance with claim 14 wherein said computer configured to display said received image data, said first density image, and said second density image on a display to facilitate radiation therapy planning and simulation calculations.

20. A computer readable medium embedded with a program configured to instruct a computer to:

receive data regarding a first energy spectrum of a scan of an object;

receive data regarding a second energy spectrum of the scan of the object;

decompose said received data to generate a first density image representative of bone material and a second density image representative of soft-tissue;

threshold said first density image to produce a first binary mask image representing bone and calcification;

extract areas identified as smaller than a predetermined size from said first binary mask image to produce a second binary mask image substantially representing calcification; and

import data into said second density image from said received data according to said extracted areas of said first binary mask image.

21. A computer readable medium in accordance with claim 20 wherein receiving data regarding a first energy spectrum of a scan of an object comprises receiving a high-energy anatomical image and receiving data regarding a second energy spectrum of the scan of the object comprises receiving a low-energy anatomical image, said computer readable medium configured to construct said computer to decompose said received data using the equation $I_b=\frac{H}{L^{\mathrm{wb}}}$

to generate said first density image, wherein 0<

w_s<

w_b<

1, I_b is the first density image, H is the high-energy anatomical image, and L is the low-energy anatomical image, and using the equation $I_s=\frac{H}{L^{w_s}},$

to generate said second density image, wherein 0<

w_s<

w_b<

1, I_s is the second density image, H is the high-energy anatomical image, and L is the low-energy anatomical image.

22. A computer readable medium in accordance with claim 20 wherein said computer further configured to instruct said computer to contrast match said second density image with said received data regarding the first energy spectrum to produce a contrast-matched soft-tissue image.

23. A computer readable medium in accordance with claim 22 wherein said computer readable medium configured to construct said computer to contrast match said second density image with said data regarding the first energy spectrum using the equation $I_{\mathrm{HS}}=I_s^{\frac{w_b}{w_b-w_s}}$

LPF(Ib-wswb-ws),

wherein 0<

w_s<

w_b<

1, I_HS is the contrast matched image, I_b is the first density image, I_s is the second density image, and LPF is a low pass boxcar filter.

24. A method for obtaining data, said method comprising:

scanning an object using a multi-energy computed tomography (MECT) system to obtain data to generate a computer tomographic (CT) anatomical image;

decomposing the obtained data to generate a first CT density image and a second CT density image; and

volume rendering at least one of the first and second CT density image.

25. A method in accordance with claim 24 further comprising at least one of storing at least one of the volume rendered first and second CT density images using a storage device and displaying at least one of the volume rendered first and second CT density images on a display.

26. A method for obtaining data, said method comprising:

scanning an object using a multi-energy computed tomography (MECT) system to obtain data to generate an anatomical image;

decomposing the obtained data to generate a first density image representative of bone material and a second density image representative of soft-tissue;

segmenting at least one of the first density image and the second density image;

volume rendering the second density image;

producing at least one binary mask image utilizing the first density image; and

utilizing the at least one binary mask image, the first density image, and the second density image to produce an additional image.

27. A method in accordance with claim 26 further comprising displaying the anatomical image, the first density image, and the second density image on a display to facilitate surgical instrument mapping.

28. A method for obtaining data, said method comprising:

scanning an object using a multi-energy computed tomography (MECT) system to obtain data to generate an anatomical image;

decomposing the obtained data to generate a first density image and a second density image;

volume rendering at least one of the first and second density image;

producing at least one binary mask image utilizing the first density image; and

utilizing the at least one binary mask image, the first density image, and the second density image to produce an additional image.

29. A method in accordance with claim 28 further comprising at least one of storing at least one of the volume rendered first and second density images using a storage device and displaying at least one of the volume rendered first and second density images on a display.