Method and apparatus of scoring an arterial obstruction

A method of coronary artery calcification scoring comprising the steps of:

• (A) acquiring imaging data for a number of imaging slices of a patient;
• (B) identifying a set of pixels of the imaging data corresponding to calcium in a coronary artery of the patient;
• (C) determining an area of the calcium in each imaging slice;
• (D) determining a subset of pixels to be considered for calcification scoring;
• (E) determining a thickness of each imaging slice;
• (F) modifying the area of the calcium of each imaging slice by a corresponding slice thickness and determining a volume of the calcium in each imaging slice therefrom;
• (G) modifying each volume by a corresponding calibration factor for each imaging slice;
• and
• (H) summing the modified volumes to determine a total volume of the calcium in the coronary artery of the patient.

A computer readable storage medium having a computer program stored thereon and representing a set of instructions that when executed by a computer causes the computer to:

• initiate a multi-slice scan of a subject;
• acquire imaging data of the subject for a number of imaging slices;
• determine a portion of the imaging data corresponding to calcium;
• determine a maximum CT number of the portion;
• determine a maximum CT number for calcium in each imaging slice;
• determine a scaling factor for each imaging slice from the maximum CT number for calcium in each imaging slice and the maximum CT number of the portion;
• determine an area of the calcium in each imaging slice;
• modify each area by a corresponding slice thickness;
• and
• determine a weighted sum of each imaging area modified by the corresponding slice thickness and the quantification factor.

A radiation emitting imaging apparatus for acquiring imaging data of a subject and for determining a calcification score from the imaging data, the radiation emitting imaging apparatus comprising:

• a rotatable gantry having an opening therein to receive a subject to be scanned;
• an HF electromagnetic energy source configured to project HF electromagnetic energy toward the subject;
• a detector assembly configured to detect HF electromagnetic energy attenuated by the subject;
• a data acquisition system connected to the detector assembly and configured to receive electrical signals from the detector assembly indicative of the HF electromagnetic energy detected;
• and
• a computer programmed to:
• generate a set of imaging data from the electrical signals;
• arrange the imaging data to correspond to a number of imaging slices, each imaging slice having a slice thickness;
• determining a portion of the imaging data corresponding to calcium;
• determine a maximum CT number of the calcium;
• determine a maximum CT number of the calcium in each imaging slice;
• determine an area of the calcium in each imaging slice;
• modify each area by a slice thickness and a ratio of the maximum CT number of the calcium for a corresponding imaging slice and the maximum CT number of the calcium;
• and
• sum each modified area to determine a calcification score.

A CT imaging system comprising:

• means for acquiring imaging data of a coronary artery of a subject, the imaging data corresponding to a number of imaging slices;
• means for isolating a portion of the imaging data corresponding to a calcium obstruction in the coronary artery;
• means for determining a thickness of each imaging slice;
• means for determining an area of the calcium obstruction in each imaging slice;
• means for determining a maximum CT number of the calcium obstruction in each imaging slice;
• means for determining a maximum CT number of the calcium obstruction;
• means for weighting a product of the area of the calcium in each imaging slice and the thickness of each imaging slice by a ratio of the maximum CT number of the calcium obstruction in each imaging slice and the maximum CT number of the calcium obstruction;
• and
• means for summing the weighted products.