Automatic indentification of anatomical features of interest from data acquired in nuclear medicine studies and automatic positioning of scintillation cameras to carry out such studies at optimal positions

• US 5,381,791 A
• Filed: 03/10/1992
• Issued: 01/17/1995
• Est. Priority Date: 03/10/1992
• Status: Expired due to Term

• Current Assignee: Siemens Gammasonics Incorporated
• Original Assignee: Siemens Medical Systems, Inc. (Siemens AG)
• Inventors: Qian, Jianzhong
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): Casler, Brian L.
• Application Number:
  US07/848,769
• Time in Patent Office: 1,043 Days
• Field of Search: 128/653.1, 128/654, 128/659, 382/6, 382/26, 378/20, 378/62, 250/363.01, 250/363.02, 250/363.10, 250/362
• US Class Current: 600/436
• CPC Class Codes: G06T 2207/10108 Single photon emission computed tomography [SPECT]
• CPC Class Codes: G06T 2207/20132 Image cropping
• CPC Class Codes: G06T 2207/30048 Heart; Cardiac
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G06T 7/12 Edge-based segmentation
• CPC Class Codes: G06T 7/64 of convexity or concavity
• CPC Class Codes: G06T 7/73 using feature-based methods

Abstract

A nuclear medicine image is scanned and pixels of maximum and minimum intensity are identified and correlated with each other using constraints which are empirically determined to relate to the feature of interest (such as the heart). The information thus obtained is used to define a region of interest in which an anatomical feature of interest may be located, and to position a scintillation camera detector to carry out a nuclear medicine study at optimal positions.

Claims

1. A method of identifying, from image data acquired in a nuclear medicine study of a patient'"'"'s body, an anatomical feature of interest, comprising:

conducting a nuclear medicine study and thereby acquiring an image of the feature, said image including, for each image pixel, an intensity representing a number of detected scintillation events which corresponds to the location of that pixel in the patient'"'"'s body;

establishing, on the basis of the feature to be identified, a scan curve and a scan direction;

scanning the image with the scan curve along the scan direction and registering, for each location of the scan curve, the pixels with local intensity maxima and minima;

grouping together, in accordance with their connectedness, some of such registered pixels, to form maxima line segments composed exclusively of pixels with local intensity maxima and minima line segments composed exclusively of pixels with local intensity minima; and

determining which of said line segments correspond with the feature by identifying whether said line segments satisfy constraints which have been empirically determined to relate to the feature.

2. The method of claim 1, wherein the feature is the interventricular septum of the heart, the scan curve is a straight line which is generally normal to the interventricular septum and the scanning direction is generally parallel to the interventricular septum.

3. The method of claim 1, further comprising the step of creating, from the line segments which have been determined to correspond to the feature, a region of interest within the image.

4. The method of claim 3, further comprising the step of searching the region of interest for at least one predetermined anatomical feature.

5. The method of claim 4, wherein the feature is the boundary of the left ventricle.

6. A method of identifying, from image data acquired in a nuclear medicine study of a patient'"'"'s body, an anatomical feature of interest, comprising:

conducting a nuclear medicine study and thereby acquiring an image of the feature, said image including, for each image pixel, an intensity representing a number of detected scintillation events which corresponds to the location of that pixel in the patient'"'"'s body;

mapping the image to a local curvature image wherein only pixels with local intensity maxima and minima have non-zero values;

grouping together, in accordance with their connectedness, at least some of such non-zero value pixels, to form maxima line segments composed exclusively of pixels with local intensity maxima and minima line segments composed exclusively of pixels with local intensity minima; and

determining which of said line segments correspond with the feature by identifying whether said line segments satisfy constraints which have been empirically determined to relate to the feature.

7. A method of optimizing the position of a scintillation camera detector with respect to a target organ within the body of a patient and thereby optimizing image data acquired in a nuclear medicine study, comprising:

acquiring a first image of the target organ at an initially preferred position of the detector with respect to the patient'"'"'s body, said first image including, for each image pixel, an intensity representing a number of detected scintillation events which corresponds to the location of that pixel in the patient'"'"'s body;

establishing, on the basis of the target organ, a scan curve and a scan direction;

scanning the first image with the scan curve along the scan direction and registering, for each location of the scan curve, the pixels with local intensity maxima and minima;

grouping together, in accordance with their connectedness, some of such registered pixels, to form maxima line segments composed exclusively of pixels with local intensity maxima and minima line segments composed exclusively of pixels with local intensity minima;

determining which of said line segments correspond with anatomical features of the target organ by identifying whether said line segments satisfy constraints which have been empirically determined to relate to said features;

ascertaining, from the line segments which have been so determined to correspond to the feature, a current position of the scintillation camera detector with respect to said target organ;

establishing a second preferred position of the scintillation camera detector with respect to the target organ;

acquiring a second image of the target organ at said second preferred position of the detector with respect to the patient'"'"'s body, said second image including second image pixels and for each second image pixel, an intensity representing that number of detected scintillation events which correspond to the location of that pixel in the patient'"'"'s body;

scanning the second image with the scan curve along the scan direction and registering, for each location of the scan curve, the second image pixels with local intensity maxima and minima;

grouping together, in accordance with their connectedness, some of such registered second image pixels, to form second image maxima line segments composed exclusively of second image pixels with local intensity maxima and second image minima line segments composed exclusively of second image pixels with local intensity minima;

determining which of said second image line segments correspond with anatomical features of the target organ by identifying whether said second image line segments satisfy constraints which have been empirically determined to relate to said features; and

ascertaining, from the second image line segments which have been so determined to correspond to the feature, a current position of the scintillation camera detector with respect to said target organ.

8. The method of claim 7, further comprising the step of determining which of the first and second positions is better for conducting the study.

9. The method of claim 7, further comprising the step of automatically moving the scintillation camera detector to an optimized position determined by comparing information acquired at the first position with information acquired at the second position.

10. A method of identifying a patient'"'"'s cardiac ventricles and interventricular septum from image data acquired in a gated cardiac bloodpool study of the patient'"'"'s heart, comprising:

acquiring a nuclear medicine image of the heart wherein the interventricular septum extends generally vertically from the top of the image to the bottom of the image, said image including, for each image pixel, an intensity representing a number of detected scintillation events which corresponds to the location of that pixel in the patient'"'"'s heart;

scanning the image with a horizontally extending line which is moved in a direction that is generally parallel to the patient'"'"'s interventricular septum and registering, for each vertical location of the horizontally extending scan line, the pixels with local intensity maxima and minima;

grouping together, in accordance with their connectedness, some of such registered pixels, to form maxima line segments composed exclusively of pixels with local intensity maxima and minima line segments composed exclusively of pixels with local intensity minima;

identifying S-patterns wherein a minima line segment intervenes, along the horizontally extending scan line, between two maxima line segments; and

extracting, from all such identified S-patterns, and in accordance with constraints which have been empirically determined to relate to the interventricular septum and the cardiac ventricles, that single S-pattern which best corresponds to the long axes of the ventricles and the intervening interventricular septum.

11. The method of claim 10, wherein said scanning and registration step includes the step of mapping the image to a local curvature image in which only local maxima and minima have non-zero values.

12. The method of claim 10, further comprising the steps of determining, within the image and from the line segments in said single S-pattern, a region of interest which includes only the left ventricle.

13. The method of claim 12, further comprising the steps of adaptively segmenting the left ventricle within the region of interest and creating a graphical plot of the boundary of the left ventricle.

14. The method of claim 13, further comprising the step of superposing the plot upon the image.

15. Apparatus for identifying a patient'"'"'s cardiac ventricles and interventricular septum from image data acquired in a gated cardiac bloodpool study of the patient'"'"'s heart, comprising:

scintillation camera means for acquiring and storing a nuclear medicine image of the heart wherein the interventricular septum extends generally vertically from the top of the image to the bottom of the image, said image including, for each image pixel, an intensity representing the number of detected scintillation events which correspond to the location of that pixel in the patient'"'"'s heart; and

computer means, said computer means comprising

means for scanning the image with a horizontally extending line which is moved in a direction that is generally parallel to the patient'"'"'s interventricular septum and registering, for each vertical location of the horizontally extending scan line, the pixels with local intensity maxima and minima,

means for grouping together, in accordance with their connectedness, some of such registered pixels, to form maxima line segments composed exclusively of pixels with local intensity maxima and minima line segments composed exclusively of pixels with local intensity minima,

means for identifying S-patterns wherein a minima line segment intervenes, along the horizontally extending scan line, between two maxima line segments, and

means for extracting, from all such identified S-patterns, and in accordance with constraints which have been empirically determined to relate to the interventricular septum and the cardiac ventricles, a single S-pattern which best corresponds to the long axes of the ventricles and the intervening interventricular septum.

16. The apparatus of claim 15, wherein said computer means further includes means for mapping the image to a local curvature image in which only local maxima and minima have non-zero values.

17. The apparatus of claim 15, wherein said computer means further includes means for determining, within the image and from the line segments in said single S-pattern, a region of interest which includes only the left ventricle.

18. The apparatus of claim 17, wherein said computer means further includes means for adaptively segmenting the left ventricle within the region of interest and creating a graphical plot of the boundary of the left ventricle.

19. The apparatus of claim 18, further comprising a display and means for displaying, upon the display, a superposition of the plot and the image.