Method and apparatus for volume scoring calcification concentrations of a CT scan

1. A method for volume scoring a concentration of calcification within a region of interest, comprising:

receiving a value for a first calcium lesion volume based on the concentration of calcification within the region of interest;

determining an intensity value of the concentration of calcification within the region of interest;

calculating the slope of a regression line based on the determined intensity value; and

calculating a second calcium lesion volume based on the first calcium lesion volume and the calculated slope of the regression line.

2. The method for volume scoring a concentration of calcification set forth in claim 1 , wherein said receiving a value for a first calcium lesion volume comprises:

acquiring projection data representing the calcium concentration of a CT scan of an object;

defining a calcified voxel within the region of interest based on the acquired projection data;

determining a slice thickness of the acquired projection data;

calculating a calcified voxel volume based on the pixel area of the calcified voxel and the slice thickness of the acquired projection data; and

calculating a first calcium lesion volume based on the calculated calcified voxel volume.

3. The method for volume scoring set forth in claim 1 , wherein said determining an intensity value further comprises:

determining a mean intensity value.

4. The method for volume scoring set forth in claim 1 , wherein said calculating a second calcium lesion volume further comprises:

calculating a second calcium lesion volume having a score accuracy error equal to or greater than about −10% and equal to or less than about +10%.

5. The method for volume scoring set forth in claim 2 , wherein said determining a slice thickness further comprises:

determining a slice thickness equal to or greater than about 1.25 millimeters and equal to or less than about 5 millimeters.

6. The method for volume scoring set forth in claim 5 , wherein said determining a slice thickness further comprises:

determining a slice thickness equal to or greater than about 1.25 millimeters and equal to or less than about 2.5 millimeters.

7. The method for volume scoring set forth in claim 2 , wherein said defining a calcified voxel within the region of interest further comprises:

defining a calcified voxel within the region of interest based on a signal attenuation threshold and a pixel connectivity value.

8. The method for volume scoring set forth in claim 7 , wherein said defining a calcified voxel within the region of interest further comprises:

defining a calcified voxel within the region of interest based on a signal attenuation of greater than about 130 Hounsfield Units and a pixel connectivity value of 2.

9. The method for volume scoring set forth in claim 2 , wherein said determining a slice thickness further comprises;

adjusting the slice thickness by the slice spacing for overlapping slices.

10. A method for volume scoring a concentration of calcification within a region of interest, comprising:

receiving a value for a first calcium lesion volume based on the concentration of calcification within the region of interest;

determining an intensity value of the concentration of calcification within the region of interest;

calculating the slope of a regression line based on the determined intensity value and according to a non-linear function (y); and

calculating a second calcium lesion volume based on the first calcium lesion volume and the calculated slope of the regression line.

11. The method for volume scoring set forth in claim 10 , wherein said calculating a second calcium lesion volume further comprises:

calculating a second calcium lesion volume according to the following equation

(second calcium lesion volume)=(first calcium lesion volume)/( y ).

12. The method for volume scoring set forth in claim 10 , wherein said calculating the slope of a regression line further comprises:

calculating the slope of a regression line based on measured data points and weighting data points.

13. A method for volume scoring a concentration of calcification within a region of interest, comprising:

receiving a value for a first calcium lesion volume based on the concentration of calcification within the region of interest;

determining an intensity value of the concentration of calcification within the region of interest;

calculating the slope of a regression line based on the determined intensity value and according to the following equation

y=− 1.13243+1.44 E− 02 *x− 2.65 E− 05 *x 2 +1.59 E− 08 *x 3

wherein x represents the mean intensity value of the concentration of calcification within the region of interest in Hounsfield Units and y represents the slope of the regression line; and

calculating a second calcium lesion volume based on the first calcium lesion volume and the calculated slope of the regression line.

14. The method for volume scoring set forth in claim 13 , wherein said calculating a second calcium lesion volume further comprises:

calculating a second calcium lesion volume according to the following equation

second calcium lesion volume=(first calcium lesion volume)/ y.

15. A system for volume scoring a concentration of calcification within a region of interest, said system comprising a computer programmed to:

receive a value for a first calcium lesion volume based on the concentration of calcification within the region of interest;

determine an intensity value of the concentration of calcification within the region of interest;

calculate the slope of a regression line based on the measured intensity value; and

calculate a second calcium lesion volume based on the first calcium lesion volume and the calculated slope of the regression line.

16. The system for volume scoring of claim 15 , wherein said system comprising a computer programmed to receive a value for a first calcium lesion volume comprises the computer programmed to:

acquire projection data representing the calcium concentration of a CT scan of an object;

define a calcified voxel within the region of interest based on the acquired projection data;

determine a slice thickness of the acquired projection data;

calculate a calcified voxel volume based on the pixel area of the calcified voxel and the slice thickness of the acquired projection data; and

calculate a first calcium lesion volume based on the calculated calcified voxel volume.

17. The system for volume scoring of claim 15 , wherein said system comprising a computer programmed to determine an intensity value further comprises the computer programmed to:

determine a mean intensity value.

18. The system for volume scoring of claim 15 , wherein said system comprising a computer programmed to calculate the slope of a regression line further comprises the computer programmed to:

calculate the slope of a regression line according to the following equation:

y=− 1.13243+1.44 E− 02 *x− 2.65 E− 05 *x 2 +1.59 E− 08 *x 3 ;

wherein x represents the mean intensity value of the concentration of calcification within the region of interest in Hounsfield Units and y represents the slope of the regression line.

19. The system for volume scoring of claim 18 , wherein said system comprising a computer programmed to calculate a second calcium lesion volume further comprises the computer programmed to:

calculate a second calcium lesion volume according to the following equation:

second calcium lesion volume=(first calcium lesion volume)/ y.

20. The system for volume scoring of claim 15 , wherein said system comprising a computer programmed to calculate a second calcium lesion volume further comprises the computer programmed to:

calculate a second calcium lesion volume having a score accuracy error equal to or greater than about −10% and equal to or less than about +10%.

21. The system for volume scoring of claim 16 , wherein said system comprising a computer programmed to determine a slice thickness further comprises the computer programmed to:

determine a slice thickness equal to or greater than about 1.25 millimeters and equal to or less than about 5 millimeters.

22. The system for volume scoring of claim 21 , wherein said system comprising a computer programmed to determine a slice thickness further comprises the computer programmed to:

determine a slice thickness equal to or greater than about 1.25 millimeters and equal to or less than about 2.5 millimeters.

23. The system for volume scoring of claim 16 , wherein said system comprising a computer programmed to define a calcified voxel within a region of interest further comprises the computer programmed to:

define a calcified voxel within a region of interest based on a signal attenuation threshold and a pixel connectivity value.

24. The system for volume scoring of claim 23 , wherein said system comprising a computer programmed to define a calcified voxel within a region of interest further comprises the computer programmed to:

define a calcified voxel within a region of interest based on a signal attenuation of greater than about 130 Hounsfield Units and a pixel connectivity value of 2.

25. The system for volume scoring of claim 16 , wherein said system comprising a computer programmed to determine a slice thickness further comprises the computer programmed to:

adjust the slice thickness by the slice spacing for overlapping slices.

26. A system for volume scoring a concentration of calcification within a region of interest, said system comprising a computer programmed to:

receive a value for a first calcium lesion volume based on the concentration of calcification within the region of interest;

determine an intensity value of the concentration of calcification within the region of interest;

calculate the slope of a regression line based on the measured intensity value and according to a non-linear function (y); and

calculate a second calcium lesion volume based on the first calcium lesion volume and the calculated slope of the regression line.

27. The system for volume scoring set forth in claim 26 , wherein said system comprising a computer programmed to calculate a second calcium lesion volume further comprises the computer programmed to:

calculate a second calcium lesion volume according to the following equation

(second calcium lesion volume)=(first calcium lesion volume)/( y ).

28. The system for volume scoring of claim 26 , wherein said system comprising a computer programmed to calculate the slope of a regression line further comprises the computer programmed to:

calculate the slope of a regression line based on measured data points and weighting data points.