Method for quantifying an object in a larger structure using a reconstructed image

• US 20070003122A1
• Filed: 06/29/2005
• Published: 01/04/2007
• Est. Priority Date: 06/29/2005
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Lehel, Peter, Sirohey, Saad, Mack, David, Le, Toan, Mohr, Kelly
• Granted Patent: US 7,702,141 B2
• Time in Patent Office: Days
• US Class Current: 382/131
• CPC Class Codes: G06T 2207/10072 Tomographic images
• CPC Class Codes: G06T 2207/30101 Blood vessel; Artery; Vein; Vascular
• CPC Class Codes: G06T 7/12 Edge-based segmentation
• CPC Class Codes: G06T 7/62 of area, perimeter, diameter or volume

Abstract

A computer-implemented method for quantifying an object in a larger structure using a reconstructed image obtained from an imaging apparatus includes identifying an object boundary in a region of interest of the image and a region of exclusion, and determining a mean value of intensity in a neighborhood of the object to estimate a background value, excluding the region of exclusion. The method further includes determining an interior region, a transition region, and a background region of the object using the object boundary and a transfer function of the imaging apparatus, and determining and displaying a measure of object quantification utilizing intensities of at least one of the determined interior region or the transition region a method for quantifying an object in a larger structure using a reconstructed image obtained from an imaging apparatus.

Claims

1. A computer-implemented method for quantifying an object in a larger structure using a reconstructed image obtained from an imaging apparatus, said method comprising:

identifying an object boundary in a region of interest of the image and a region of exclusion;

determining a mean value of intensity in a neighborhood of the object to estimate a background value, excluding the region of exclusion;

determining an interior region, a transition region, and a background region of the object using the object boundary and a transfer function of the imaging apparatus; and

determining and displaying a measure of object quantification utilizing intensities of at least one of the determined interior region or the transition region.

2. A method in accordance with claim 1 wherein the measure of object quantification is at least one of mass, volume, texture, or shape of the object.

3. A method in accordance with claim 1 wherein the larger structure is a patient'"'"'s body and the object is selected from the group consisting of lesions and vessel calcifications.

4. A method in accordance with claim 3 wherein said reconstructed image is an image including a heart of the patient, wherein said image is an image selected from the group consisting of a computed tomographic (CT) image, a magnetic resonance image, and an ultrasonic image.

5. A method in accordance with claim 1 wherein said identifying an object boundary further comprises displaying an image on a display screen, accepting an electronic input indicating a portion or point within the object boundary, and growing the mark indicating the portion or point within the object boundary to encompass an estimated entirety of the object.

6. A method in accordance with claim 5 wherein said selecting a region of exclusion further comprises accepting an electronic input mark indicating a box on the displayed image representing the region of exclusion.

7. A method in accordance with claim 6 wherein said selecting a region of exclusion further comprises accepting an electronic input mark indicating a portion or point within a region of exclusion, and growing the mark indicating the portion or point within the region of exclusion to encompass an estimated exclusion region.

8. A method in accordance with claim 1 wherein said identifying an object boundary in a region of interest of the image and a region of exclusion further comprises creating a connected component list (CCs) of objects and a list of regions of exclusion.

9. A method in accordance with claim 8 wherein said image is a 3-dimensional imaging comprising a plurality of image slices and further comprising determining adjacent CC lists in one or more neighboring slices to create volume CCs.

10. A method in accordance with claim 1 wherein the imaging system has a system resolution, and further comprising determining a volume of interest as a CC plus a number of surrounding voxels in accordance with the system resolution.

11. A method in accordance with claim 1 wherein the imaging system has a system resolution, wherein the measure of object quantification is at least one of mass or volume of the object, and wherein determining an interior region, a transition region, and a background region of the object using the object boundary and a transfer function of the imaging apparatus further comprises:

setting an upper intensity threshold and a lower intensity threshold;

and, while excluding voxels in the region of exclusion,

(a) determining voxels of the object in the image in accordance with at least one of the upper intensity threshold or the lower intensity threshold;

(b) determining an inner shell of the object and an outer shell of the object in accordance with the determined voxels of the object and the system resolution,

and further wherein to determine at least one of mass or volume of the object, said method further comprises using at least one of the determined inner shell or the determined outer shell to determine the mass or volume of the object.

12. A method in accordance with claim 11 further comprising adjusting at least one of the upper intensity threshold and the lower intensity threshold and repeating said determining steps (a) and (b) until an accuracy test is satisfied.

13. A method in accordance with claim 11 wherein a measure of the volume of the object is displayed, and determining the volume of the object comprises utilizing determined voxels of the object and determining the volume of the object in accordance with the number of voxels in the determined volume of the object and a size of each voxel.

14. A method in accordance with claim 11 wherein a measure of the mass of the object is displayed, and determining the mass of the object comprises determining an adjusted interior region of the object, determining an adjusted inner shell of the object and an adjusted outer shell of the object, and determining a mass of the object in accordance with the size of each voxel, the size of an adjusted interior region of the object, and a difference between representative intensities of the adjusted interior region of the object and of the adjusted outer shell of the object.

15. A method in accordance with claim 11 wherein a measure of at least one of mass or volume of the object is displayed, and determining the mass or volume of the object comprises determining an adjusted interior region of the object, an adjusted inner shell of the object and an adjusted outer shell of the object, and determining a mass of the object in accordance with the size of each voxel, the size of the adjusted inner shell of the object, and a difference between representative intensities of the adjusted inner shell of the object and of the adjusted outer shell of the object.

16. An imaging system comprising:

a radiation source;

a radiation detector configured to detect radiation emitted by the radiation source passing through an object in a larger structure, and provide signals indicative of the object;

a processor and a display configured to utilize said signals provided by said radiation detector to display an image of the object, said image comprised of voxels;

an input device configured to accept an identification of an object boundary in a region of interest of the image and a region of exclusion; and

said imaging system further configured to;

identify the object boundary in the region of interest of the image and the region of exclusion;

determine a mean value of intensity in a neighborhood of the object to estimate a background value, excluding the region of exclusion;

determine an interior region, a transition region, and a background region of the object using the object boundary and a transfer function of the imaging apparatus; and

determine and display a measure of object quantification utilizing intensities of at least one of the determined interior region or the transition region.

17. An imaging system in accordance with claim 16 wherein the measure of object quantification is at least one of mass, volume, texture, or shape of the object.

18. An imaging system in accordance with claim 16 wherein said imaging system is an imaging system selected from the group consisting of a computed tomographic (CT) imaging system, a magnetic resonance imaging system, and an ultrasonic imaging system.

19. An imaging system in accordance with claim 16 wherein to identify an object boundary, said imaging system further configured to display an image on the display, accept an electronic input mark indicative of the object, and alter the size of the accepted mark to encompass an estimated entirety of the object.

20. An imaging system in accordance with claim 16 wherein to select a region of exclusion, said imaging system further configured to accept an electronic input mark indicating a box on the displayed image representing the region of exclusion.

21. An imaging system in accordance with claim 16 further configured to set an upper intensity threshold and a lower intensity threshold and wherein the measure of object quantification is at least one of mass or volume of the object;

and, while excluding voxels of the in the region of exclusion said imaging system further configured to;

(a) determine voxels of the object in the image in accordance with at least one of the upper intensity threshold or the lower intensity threshold; and

(b) determine an inner shell of the object and an outer shell of the object in accordance with the determined voxels of the object, the system resolution,

and further wherein to display at least one of mass or volume of the object, said imaging system further configured to use at least one of the determined inner shell or the determined outer shell to determine displayed mass or volume.

22. A machine readable medium having instructions recorded thereon configured to instruct a processor to:

identify, in an image an object in a larger structure, an object boundary in a region of interest and identify a region of exclusion;

determine a mean value of intensity in a neighborhood of the object to estimate a background value, excluding the region of exclusion;

determine an interior region, a transition region, and a background region of the object using the object boundary and a transfer function of the imaging apparatus; and

determine and display a measure of object quantification utilizing intensities of at least one of the determined interior region or the transition region.

23. A machine readable medium in accordance with claim 22 wherein the measure of object quantification is at least one of mass, volume, texture, or shape of the object.

24. A machine readable medium in accordance with claim 22 wherein, to identify an object boundary in a region of interest and identify a region of exclusion, said instructions are further configured to instruct the processor to display an image including the object on a display, accept an electronic input mark indicative of the object to be identified, and alter the size of the accepted mark to encompass an estimated entirety of the object, and further to accept an electronic input mark indicating a box on the displayed image representing the region of exclusion.

25. A machine readable medium in accordance with claim 22 wherein the measure of object quantification is at least one of mass or volume of the object, and said instructions are further configured to instruct the processor to set an upper intensity threshold and a lower intensity threshold;

and, while excluding voxels of the image in the region of exclusion,

(a) determine voxels of the object in the image in accordance with at least one of the upper intensity threshold or the lower intensity threshold; and

(b) determine an inner shell of the object and an outer shell of the object in accordance with the determined voxels of the object, the system resolution,

and further wherein to display at least one of mass or volume of the object, said instructions are further configured to instruct the processor to use at least one of the determined inner shell or the determined outer shell to determine the displayed mass or volume.