Automatic detection and quantification of coronary and aortic calcium

An automatic method to measure coronary calcium in a volumetric portion of a living subject using x-ray computed tomography (CT) by acquiring a volumetric set of CT images containing pixels representing x-ray attenuation of the subject, the method comprising:

• processing the set of CT images in a computer to automatically identify boundaries of the heart of the subject;
• processing the set of CT images in the computer to automatically identify a location of at least one coronary artery;
• using the computer to place a three-dimensional region of interest (ROI) surrounding the artery location to select a volume;
• analyzing the three-dimensional ROI with the computer to automatically identify pixels in the volume above a threshold value;
• and
• processing the pixels in the volume above the threshold value with the computer to automatically determine a calcium content of at least a portion of the coronary artery in the volume.

A volumetric method to measure calcium in arteries of the human body using computed tomography (CT) by acquiring CT images containing pixels representative of x-ray attenuation in the body, the method comprising:

• calibrating the CT images with a computer to provide calibrated CT images;
• processing the CT images with the computer to identify a location of at least one artery automatically;
• processing the CT images in a volume including the at least one artery with the computer to identify calcium within the volume automatically;
• and
• processing the calibrated CT images within the volume with the computer to quantify the calcium within the volume.

A volumetric system for quantifying calcium in coronary arteries of the body using x-ray computed tomography (CT), the system comprising:

• means for acquiring images of the arteries, the images being calibrated;
• means for determining an approximate location of at least one coronary artery automatically;
• means for automatically positioning a three-dimensional search ROI which surrounds the coronary artery location in at least one image;
• means for evaluating image elements within said three-dimensional search ROI to locate calcium;
• and
• means for quantifying the calcium in a volume of the coronary artery to generate a calcium measure.

A volumetric system to determine calcium in at least one artery of a living subject using x-ray computed tomography images, the system comprising:

• means for locating a position of an artery on images;
• means for placing three-dimensional regions of interest (ROI) surrounding the artery;
• means for locating calcium within the three-dimensional ROI;
• means for automatically locating calcium within the three-dimensional ROI attributable to bones;
• and
• means for quantifying the calcium within the three-dimensional ROI not attributed to the bones within the three-dimensional ROI.

An automated volumetric method for quantifying calcium in the aorta of a living subject from at least one computed tomography image, the method comprising:

• (a) processing the at least one computed tomography image with a computer to locate a vertebral body in an image;
• (b) processing the at least one computed tomography image with the computer to locate the aorta in the image;
• (c) defining a three-dimensional search region with the computer, the search region defined to be smaller than the image and to contain a section of the aorta;
• (d) processing the image with the computer to exclude bone of the vertebral body from the three-dimensional search region;
• (e) processing the image with the computer to identify calcified regions of the aorta within the three-dimensional search region having density values above a threshold value;
• and
• (f) processing the image with the computer to quantify calcium in the identified calcified regions.

An automatic method for measuring calcification in a volume of the aorta of a living subject, the method comprising:

• receiving into a computer an image comprising image elements representing densities of body structures in the image;
• processing the image with the computer to locate image elements representing bone;
• defining a three-dimensional search region of interest (ROI) with the computer, the three-dimensional region of interest positioned proximate to the bone;
• processing the image elements with the computer to automatically locate boundaries of the aorta in the three-dimensional region of interest;
• processing the image elements within the boundaries of the aorta with the computer to identify a calcified region within the boundaries of the aorta having densities above a threshold value;
• and
• processing the image elements within the calcified region with the computer to measure a calcium content within the calcified region.

A volumetric method for measuring coronary artery calcification of a living body having a heart, an aorta, coronary arteries, and heart valves, the method comprising:

• providing a plurality of non invasive internal images of the body as data to a computer, each image comprising image elements indicative of densities of corresponding body structures;
• processing the image elements with the computer to identify boundaries of the heart within the plurality of images, the boundaries defining a heart volume;
• processing the image elements in the heart volume with the computer to divide the heart volume into an inferior region, a middle region, and a superior region;
• processing the image elements within the inferior region of the heart volume with the computer to automatically locate calcium within the inferior region and attributing the inferior region calcium to calcification of the coronary arteries;
• processing the image elements within the middle region of the heart volume with the computer to automatically locate calcium within the middle region and attributing a portion of the middle region calcium to calcification of the coronary arteries and a remaining portion of the middle region calcium to calcification of the heart valves;
• and
• processing the image elements within the superior region of the heart volume with the computer to automatically locate calcium within the superior region and attributing a portion of the superior region calcium to calcification of the coronary arteries and a remaining portion of the superior region calcium to calcification of the aorta.

A volumetric method for measuring coronary artery calcification of a living body having a heart, the method comprising:

• providing a plurality of noninvasive internal images to a computer, each image comprising image elements indicative of densities of corresponding body structures;
• processing the image elements with the computer to identify boundaries of the heart within the plurality of images, the boundaries defining a heart volume;
• processing the image elements with the computer to define a shell volume at the identified boundaries of the heart, the shell volume having a thickness greater than a diameter of a coronary artery;
• and
• processing the image elements within the shell volume to identify a calcified region within the shell volume having density values above a threshold value.