Method and system for automatic analysis of blood vessel structures to identify calcium or soft plaque pathologies

• US 7,940,977 B2
• Filed: 11/22/2006
• Issued: 05/10/2011
• Est. Priority Date: 10/25/2006
• Status: Expired due to Fees

• Current Assignee: Rcadia Medical Imaging, Ltd.
• Original Assignee: Rcadia Medical Imaging, Ltd.
• Inventors: Begelman, Grigory, Walach, Eugene, Levanon, Shai, Ohayon, Shay, Goldenberg, Roman
• Primary Examiner(s): Perungavoor; Sath V
• Assistant Examiner(s): HEIDEMANN, JASON E
• Application Number:
  US11/562,906
• Publication Number:
  US 20080103389A1
• Time in Patent Office: 1,630 Days
• Field of Search: None
• US Class Current: 382/133
• CPC Class Codes: G06T 2207/10081 Computed x-ray tomography [CT]
• CPC Class Codes: G06T 2207/20044 Skeletonization; Medial axis transform
• CPC Class Codes: G06T 2207/30101 Blood vessel; Artery; Vein; Vascular
• CPC Class Codes: G06T 7/62 of area, perimeter, diameter or volume
• CPC Class Codes: Y10S 128/922 including image analysis

Abstract

A method of identifying a calcium and/or a soft plaque deposit in a blood vessel using imaging data of the blood vessel is provided. A first threshold is applied to a slice of three-dimensional imaging data of a blood vessel to define voxels above the first threshold. A maximum intensity of the blood vessel is identified from the defined voxels. A distance from the identified maximum intensity to a center of the blood vessel is calculated and is compared with a distance threshold. If the calculated distance is greater than the distance threshold, a calcium deposit is identified. A second threshold is applied to the slice to define voxels below the second threshold. If a calcium deposit is identified or if the defined voxels below the threshold have a half-moon shape, a soft plaque deposit is identified.

Claims

1. A method of identifying a calcium or a soft plaque deposit in a blood vessel using imaging data of the blood vessel, the method comprising:

(a) applying a first threshold to a slice of three-dimensional imaging data of a blood vessel to define voxels above the first threshold;

(b) identifying a maximum intensity of the blood vessel from the defined voxels above the first threshold;

(c) calculating a distance from the identified maximum intensity to a center of the blood vessel;

(d) comparing the calculated distance with a distance threshold;

(e) if the calculated distance is greater than the distance threshold, identifying a calcium deposit;

(f) applying a second threshold to the slice to define voxels below the second threshold;

(g) if a calcium deposit is identified, identifying a soft plaque deposit from the defined voxels below the second threshold;

(h) if a calcium deposit is not identified, determining if the defined voxels below the second threshold have a half-moon shape;

(i) if the defined voxels below the second threshold have a half-moon shape, identifying a soft plaque deposit;

(j) calculating a calcium area of the identified calcium deposit;

(k) calculating a plaque area of the identified soft plaque deposit; and

(l) calculating an obstruction parameter based on the calculated plaque area and on the calculated calcium area.

2. The method of claim 1, further comprising repeating (a)-(k) for a plurality of slices.

3. The method of claim 2, further comprising calculating an obstruction parameter based on a sum of the calculated plaque area and the calculated calcium area.

4. The method of claim 3, wherein calculating the obstruction parameter is further based on the sum divided by a total area of the blood vessel.

5. The method of claim 4, wherein an obstruction severity is determined based on the calculated obstruction parameter.

6. The method of claim 5, wherein the obstruction severity is labeled severe if the obstruction parameter is greater than a severity threshold for a plurality of slices.

7. The method of claim 6, wherein the severity threshold is approximately 0.5.

8. The method of claim 1, further comprising:

receiving imaging data including a heart region, a pulmonary artery region, an ascending aorta region, and a thoraco-abdominal aorta region of a patient;

identifying the heart region from the imaging data;

analyzing the identified heart region to detect a coronary pathology;

identifying an ascending aorta object from the ascending aorta region of the imaging data;

analyzing the identified ascending aorta object to detect an aortic dissection;

identifying an abdominal aorta object from the thoraco-abdominal aorta region;

analyzing the identified abdominal aorta object to detect an aortic dissection;

identifying a left main pulmonary artery object and a right main pulmonary artery object from the pulmonary artery region of the imaging data;

analyzing the identified left main pulmonary artery object and the identified right main pulmonary artery object to detect a pulmonary embolism; and

generating a report including any detected coronary pathology, any detected aortic dissection, and any detected pulmonary embolism.

9. The method of claim 8, wherein identifying the heart region comprises:

projecting the received imaging data into a first plane of three dimensions of the received imaging data;

applying a first threshold to the first plane of data, wherein the first threshold is selected to eliminate a first pixel associated with air;

identifying a largest first connected component from the first threshold applied data;

calculating a first center of mass of the identified largest first connected component to define a first coordinate and a second coordinate;

projecting the received imaging data into a second plane of the three dimensions, wherein the second plane is perpendicular to the first plane;

applying a second threshold to the second plane of data, wherein the second threshold is selected to eliminate a second pixel associated with air;

identifying a largest second connected component from the second threshold applied data; and

calculating a second center of mass of the identified largest second connected component to define a third coordinate;

wherein a center of a heart region is defined from the defined first coordinate, the defined second coordinate, and the defined third coordinate; and

further wherein the heart region has a width in each of the three dimensions.