Medical image processing apparatus and medical image processing method

1. A medical image processing apparatus comprising:

an image storage memory configured to store data of a plurality of images in different respiratory phases which represent a morphology of an object chest portion;

a calculation circuitry configured to calculate a motion amount of a region between the plurality of images for each pixel or area;

a level decision circuitry configured to decide a level concerning a severity of chronic obstructive pulmonary disease for each pixel or area based on a combination of at least two of the motion amount, a feature value obtained from pixel values of the image, and a change rate of a size of the area; and

an output interface circuitry configured to output information concerning the decided level.

2. The medical image processing apparatus according to claim 1 , wherein the feature value comprises the pixel value, a difference between the pixel values, a ratio of the number of pixels having pixel values less than a threshold to the number of pixels in the area, a variance of a pixel value distribution in the area, or an average value of pixel values in the area.

3. The medical image processing apparatus according to claim 1 , further comprising a generation circuitry configured to generate a two-dimensional or three-dimensional map concerning the decided level.

4. The medical image processing apparatus according to claim 1 , wherein the image comprises a two-dimensional image or a three-dimensional image.

5. The medical image processing apparatus according to claim of 1 , wherein the calculation circuitry calculates a vector for the each pixel or area.

6. The medical image processing apparatus according to claim 5 , wherein the motion amount is represented by one direction component or two direction components of the vector.

7. The medical image processing apparatus according to claim 5 , wherein the change rate of the size of the area is calculated from a ratio of an area or volume of an area defined by a plurality of pixels of another image, the plurality of pixels respectively corresponding to a plurality of adjacent pixels of one of the plurality of images via the vector, to an area or volume of an area defined by the plurality of adjacent pixels.

8. The medical image processing apparatus according to claim 1 , wherein the plurality of images include an inspiration image generated at the time of inspiration and an expiration image generated at the time of expiration, and

the motion amount, the feature value, and the change rate are calculated by using the inspiration image and the expiration image.

9. The medical image processing apparatus according to claim 1 , wherein a right lung area and a left lung area of lung fields are used as the areas.

10. The medical image processing apparatus according to claim 9 , wherein the right lung area and the left lung area are segmented into a plurality of lung lobe areas.

11. The medical image processing apparatus according to claim 10 , wherein each of the lung lobe areas is segmented into a plurality of lung segment areas.

12. The medical image processing apparatus according to claim 1 , wherein a block area as an aggregate of a predetermined number of adjacent voxels is used as the area.

13. The medical image processing apparatus according to claim 1 , further comprising a registration processing circuitry configured to register anatomical positions between the plurality of images,

wherein the calculation circuitry calculates a motion amount of a region between the registered images.

14. A medical image processing apparatus comprising:

a storage memory configured to store data of first volume data and second volume data in different respiratory phases which represent a morphology of an object chest portion;

a calculation circuitry configured to calculate a motion vector of a region between the first volume data and the second volume data for each pixel or area;

a level decision circuitry configured to decide a level concerning a severity of chronic obstructive pulmonary disease for each pixel or area based on a combination of at least two of the motion vector, a feature value obtained from pixel values of the first volume data and the second volume data, and a change rate of a size of the area; and

a generation circuitry configured to generate a map indicating a spatial distribution concerning the decided levels.

15. The medical image processing apparatus according to claim 14 , wherein the first volume data is acquired at the time of inspiration, and the second volume data is acquired at the time of expiration.

16. The medical image processing apparatus according to claim of 14 , wherein the level decision circuitry decides the level based on the feature value and one direction component concerning the motion vector.

17. The medical image processing apparatus according to claim 14 , wherein the level decision circuitry decides the level based on the feature value and two direction components concerning the motion vector.

18. The medical image processing apparatus according to claim 14 , wherein the feature value comprises the pixel value, a difference between the pixel values, a ratio of the number of pixels having pixel values less than a threshold to the number of pixels in the area, a variance of a pixel value distribution in the area, or an average value of pixel values in the area.

19. The medical image processing apparatus according to claim 14 , wherein as the motion vector, a vector indicating an average distance, a vector indicating an intermediate value of distances, or a vector indicating a median value of distances is selected from a plurality of vectors included in each of the areas.

20. The medical image processing apparatus according to claim 14 , wherein the first volume data and the second volume data are generated by an X-ray computed tomography apparatus or a magnetic resonance imaging apparatus.

21. The medical image processing apparatus according to claim 14 , wherein as the area, a lung field area is segmented into a right lung area and left lung area, the right lung area and the left lung area each are segmented into a plurality of lung lobe areas, and each of the lung lobe areas is segmented into a plurality of lung segment areas.

22. The medical image processing apparatus according to claim 14 , wherein the motion vector is differentiated into a Z-axis direction component indicating a diaphragm moving direction, a Y-axis direction component indicating a sternum moving direction, and an X-axis direction component perpendicular to the Z-axis and the Y-axis.

23. The medical image processing apparatus according to claim 14 , further comprising a registration processing circuitry configured to register anatomical positions between the plurality of images,

wherein the calculation circuitry calculates a motion vector of a region between the registered images.

24. The medical image processing apparatus according to claim 14 , wherein the change rate of the size of the area is calculated from a ratio of an area or volume of an area defined by a plurality of voxels on the second volume data, the plurality of voxels respectively corresponding to a plurality of adjacent voxels on the first volume data via the motion vector, to an area or volume of an area defined by the plurality of adjacent voxels.

25. A medical image processing method comprising:

anatomically registering first volume data and second volume data in different respiratory phases which represent a morphology of an object chest portion;

calculating a motion vector between the registered first volume data and second volume data for each voxel or area;

deciding a level concerning a severity of chronic obstructive pulmonary disease for each pixel or area based on a combination of at least two of the motion vector, a feature value obtained from pixel values of the first volume data and the second volume data, and a change rate of a size of the area; and

generating a map indicating a spatial distribution concerning the decided levels.