X-ray diagnostic apparatus and image processing apparatus

1. An X-ray diagnostic apparatus, comprising:

an X-ray generator configured to generate X-rays;

a flat panel detector configured to detect the X-rays;

a grid provided between the X-ray generator and the flat panel detector; and

processing circuitry configured to

perform noise homogenization processing on original image data, obtained based on X-rays having passed through the grid and detected by the flat panel detector, to generate processed original image data in which pixel-value dependence of noise is reduced,

convert the processed original image data into a plurality of pieces of frequency band data,

remove interference fringes contained in at least one piece of frequency band data among the pieces of frequency band data,

reduce noise contained in the pieces of frequency band data,

generate image data by adding a plurality of pieces of the noise-reduced frequency band data,

perform noise homogenization reverse processing on the generated image data to generate processed image data, and

correct a scattered radiation component of the processed image data based on a difference between a scattered radiation component contained in the X-rays having passed through the grid and a scattered radiation component that results when the X-rays pass through a virtual grid that removes scattered radiation to a larger extent than the grid, wherein the virtual grid is not present when obtaining the original image data.

2. The X-ray diagnostic apparatus according to claim 1 , wherein the grid has a lattice density so that a frequency of the interference fringes is a frequency, within a range of a Nyquist frequency of the flat panel detector to half the Nyquist frequency, nearer to the Nyquist frequency.

3. The X-ray diagnostic apparatus according to claim 1 , wherein the grid is formed with a lattice ratio and of an intermediate substance that cause direct radiation contained in X-rays having passed through a subject to pass therethrough easily.

4. The X-ray diagnostic apparatus according to claim 2 , wherein the grid is formed with a lattice ratio and of an intermediate substance that cause direct radiation contained in X-rays having passed through a subject to pass therethrough easily.

5. The X-ray diagnostic apparatus according to claim 3 , wherein the grid has the lattice ratio represented as a ratio of foil interval to thickness, within a range of 1:6 to 1:10 and has fiber as an intermediate substance.

6. The X-ray diagnostic apparatus according to claim 4 , wherein the grid has the lattice ratio represented as a ratio of foil interval to thickness, within a range of 1:6 to 1:10 and has fiber as an intermediate substance.

7. The X-ray diagnostic apparatus according to claim 1 , wherein the processing circuitry is configured to reduce the noise contained in the pieces of frequency band data, the noise being homogenized so as to be constant regardless of a pixel value.

8. The X-ray diagnostic apparatus according to claim 2 , wherein the processing circuitry is configured reduce the noise contained in the pieces of frequency band data, the noise being homogenized so as to be constant regardless of a pixel value.

9. The X-ray diagnostic apparatus according to claim 3 , wherein the processing circuitry is configured to reduce the noise contained in the pieces of frequency band data, the noise being homogenized so as to be constant regardless of a pixel value.

10. The X-ray diagnostic apparatus according to claim 4 , wherein the processing circuitry is configured to reduce the noise contained in the pieces of frequency band data, the noise being homogenized so as to be constant regardless of a pixel value.

11. The X-ray diagnostic apparatus according to claim 5 , wherein the processing circuitry is configured to reduce the noise contained in the pieces of frequency band data, the noise being homogenized so as to be constant regardless of a pixel value.

12. The X-ray diagnostic apparatus according to claim 6 , wherein the processing circuitry is configured to reduce the noise contained in the pieces of frequency band data, the noise being homogenized so as to be constant regardless of a pixel value.

13. An image processing apparatus, comprising:

processing circuitry configured to

perform noise homogenization processing on original image data, obtained based on X-rays having passed through a grid and detected by a flat panel detector, to generate processed original image data in which pixel-value dependence of noise is reduced,

convert the processed original image data into a plurality of pieces of frequency band data,

remove interference fringes contained in at least one piece of frequency band data among the pieces of frequency band data,

reduce noise contained in the pieces of frequency band data,

generate image data by adding a plurality of pieces of the noise-reduced frequency band data,

perform noise homogenization reverse processing on the generated image data to generate processed image data, and

correct a scattered radiation component of the processed image data based on a difference between a scattered radiation component contained in the X-rays having passed through the grid and a scattered radiation component that results when the X-rays pass through a virtual grid that removes scattered radiation to a larger extent than the grid, wherein the virtual grid is not present when obtaining the original image data.

14. The image processing apparatus according to claim 13 , wherein the processing circuitry is configured to reduce the noise contained in the pieces of frequency band data, the noise being homogenized so as to be constant regardless of a pixel value.

15. An image processing apparatus, comprising:

processing circuitry configured to

perform noise homogenization processing on original image data, obtained based on X-rays having passed through a grid and detected by a flat panel detector, to generate processed original image data in which pixel-value dependence of noise is reduced,

convert the processed original image data into a plurality of pieces of frequency band data,

reduce noise contained in the pieces of frequency band data,

generate image data by adding a plurality of pieces of the noise-reduced frequency band data,

perform noise homogenization reverse processing on the generated image data to generate processed image data, and

correct a scattered radiation component of the processed image data based on a difference between a scattered radiation component contained in the X-rays detected by the flat panel detector and a scattered radiation component that results when the X-rays pass through a virtual grid that removes scattered radiation to a larger extent than the grid, wherein the virtual grid is not present when obtaining the original image data.

16. The image processing apparatus according to claim 15 , wherein the processing circuitry is configured to reduce the noise contained in the pieces of frequency band data, the noise being homogenized so as to be constant regardless of a pixel value.

17. An X-ray diagnostic apparatus, comprising:

an X-ray generator configured to generate X-rays;

a flat panel detector configured to detect the X-rays;

a grid provided between the X-ray generator and the flat panel detector: and

processing circuitry configured to

convert original image data based on X-rays having passed through the grid and detected by the flat panel detector into a plurality of pieces of frequency band data,

remove interference fringes contained in at least one piece of frequency band data among the pieces of frequency band data,

reduce noise contained in the pieces of frequency band data,

correct a scattered radiation component of the original image data, based on a difference between a scattered radiation component contained in the X-rays having passed through the grid and a scattered radiation component that results when the X-rays pass through a virtual grid that removes scattered radiation to a larger extent than the grid, wherein the virtual grid is not present when obtaining the original image data, and

generate image data by adding a plurality of pieces of frequency band data after being processed.

18. An image processing apparatus, comprising:

processing circuitry configured to

convert original image data based on X-rays having passed through a grid and detected by a flat panel detector into a plurality of pieces of frequency band data,

remove interference fringes contained in at least one piece of frequency band data among the pieces of frequency band data,

reduce noise contained the pieces of frequency band data,

correct a scattered radiation component of the original image data based on a difference between a scattered radiation component contained in the X-rays having passed through the grid and a scattered radiation component that results when the X-rays pass through a virtual grid that removes scattered radiation to a larger extent than the grid, wherein the virtual grid is not present when obtaining the original image data, and

generate image data by adding a plurality of pieces of frequency band data after being processed.

19. An image processing apparatus, comprising:

processing circuitry configured to

convert processed original image data based on X-rays having passed through a grid and detected by a flat panel detector into a plurality of pieces of frequency band data,

reduce noise contained in the pieces of frequency band data,

correct a scattered radiation component of the original image data based on a difference between a scattered radiation component contained in the X-rays having passed through the grid and a scattered radiation component that results when the X-rays pass through a virtual grid that removes scattered radiation to a larger extent than the grid, wherein the virtual grid is not present when obtaining the original image data, and

generate image data by adding a plurality of pieces of frequency band data after being processed.