X-RAY COMPUTED TOMOGRAPHY APPARATUS AND IMAGE PROCESSING APPARATUS

• US 20090028409A1
• Filed: 07/22/2008
• Published: 01/29/2009
• Est. Priority Date: 07/24/2007
• Status: Active Grant

• Current Assignee: Toshiba Medical Systems Corporation (Canon Inc.)
• Original Assignee: Toshiba Medical Systems Corporation (Canon Inc.), Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: TSUKAGOSHI, Shinsuke, Fujisawa, Yasuko
• Granted Patent: US 7,715,519 B2
• Time in Patent Office: Days
• US Class Current: 382/131
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/481 involving the use of contrast agents
• CPC Class Codes: A61B 6/504 for diagnosis of blood vessels, e.g. by angiography
• CPC Class Codes: A61B 6/507 for determination of haemodynamic parameters, e.g. perfusion CT
• CPC Class Codes: A61B 6/5235 combining images from the same or different ionising radiation imaging techniques, e.g. PET and CT
• CPC Class Codes: Y10S 378/901 Computer tomography program or processor

Abstract

An X-ray tube generates X-rays. An X-ray detector detects X-rays generated from the X-ray tube and transmitted through an object to be examined. A rotating frame continuously rotates the X-ray tube and the X-ray detector around the object. A reconstruction unit reconstructs a plurality of first volume data sets with different scan times for the same scan area of the object on the basis of an output from the X-ray detector. An image processing unit generates single second volume data set corresponding to a maximum value, an average value, a median value, or minimum value of the plurality of reconstructed first volume data sets in the temporal direction.

Claims

1. An X-ray computed tomography apparatus comprising:

an X-ray tube which generates X-rays;

an X-ray detector which detects X-rays generated from the X-ray tube and transmitted through an object to be examined;

a rotating mechanism unit which continuously rotates the X-ray tube and the X-ray detector around the object;

a reconstruction unit which reconstructs a plurality of first volume data sets with different scan times for the same scan area of the object on the basis of an output from the X-ray detector; and

an image processing unit which generates single second volume data set corresponding to one of a maximum value, an average value, a median value, and minimum value of the plurality of reconstructed first volume data sets in a temporal direction.

2. The apparatus according to claim 1, further comprising:

a tomogram generation unit which generates data of a tomogram on the basis of the second volume data set;

a blood vessel extraction unit which extracts a blood vessel portion from the generated tomogram by threshold processing; and

a display unit which superimposes and displays the extracted blood vessel portion and a functional image for an index representing a blood flow dynamic state.

3. The apparatus according to claim 2, further comprising a color information assignment unit which assigns different pieces of color information to a blood vessel portion and a tissue portion which are included in the second volume data set.

4. The apparatus according to claim 1, wherein the image processing unit generates the second volume data set by setting one of a maximum value, an average value, a median value, and a minimum value of voxel values of a plurality of voxels at the same position in the plurality of first volume data sets as a voxel value of a voxel at the same position in the second volume data set.

5. The apparatus according to claim 1, wherein the image processing unit generates the second volume data set on the basis of first volume data sets, of the plurality of first volume data sets, which concerns a predetermined period of time.

6. The apparatus according to claim 5, wherein the predetermined period of time is determined on the basis of a time density curve for a predetermined area of the plurality of first volume data sets.

7. The apparatus according to claim 1, wherein a length of the object in the scan area in a body axis direction is not less than 8 cm.

8. The apparatus according to claim 1, further comprising a control unit which controls the X-ray tube, the X-ray detector, and the rotating mechanism unit to continuously scan the same scan area of the object.

9. The apparatus according to claim 1, further comprising a selection unit which causes the image processing unit to selectively execute projection processing for a temporal direction or projection processing for a spatial direction.

10. The apparatus according to claim 1, further comprising a designation unit which designates at least one of a time range in projection processing for a temporal direction and a space range in projection processing for a spatial direction with respect to the image processing unit.

11. An X-ray computed tomography apparatus comprising:

an X-ray tube which generates X-rays;

an X-ray detector which detects X-rays generated from the X-ray tube and are transmitted through an object to be examined;

a rotating mechanism unit which continuously rotates the X-ray tube and the X-ray detector around the object;

a reconstruction unit which reconstructs a plurality of first volume data sets with different scan times for the same scan area of the object on the basis of an output from the X-ray detector; and

an image processing unit which generates single second volume set data by processing the plurality of reconstructed first volume data sets.

12. An X-ray computed tomography apparatus comprising:

an X-ray tube which generates X-rays;

an X-ray detector which detects X-rays generated from the X-ray tube and are transmitted through an object to be examined;

a rotating mechanism unit which continuously rotates the X-ray tube and the X-ray detector around the object;

a first projection data generation unit which generates a plurality of first projection data sets with different scan times for the same scan area of the object on the basis of an output from the X-ray detector;

a second projection data generation unit which generates a single second projection data set corresponding to one of a maximum value, an average value, a median value, and a minimum value of the plurality of generated first projection data sets in a temporal direction; and

a reconstruction unit which reconstructs volume data set on the basis of the generated second projection data set.

13. The apparatus according to claim 12, wherein the projection data processing unit generates the second projection data set by setting one of a maximum value, an average value, a median value, and a minimum value of a plurality of projection data values of the plurality of projection data sets at the same position as a projection data value at the same position in the second projection data set.

14. An image processing apparatus comprising:

a storage unit which stores a plurality of first volume data sets with different scan times for the same scan area of an object to be examined; and

an image processing unit which generates single second volume data set corresponding to one of a maximum value, an average value, a median value, and a minimum value of the plurality of first volume data sets in a temporal direction.

15. An image processing apparatus comprising:

a storage unit which stores a plurality of first projection data sets with different scan times which are generated by continuously scanning the same scan area of an object to be examined;

a projection data processing unit which generates a single second projection data set corresponding to one of a maximum value, an average value, a median value, and a minimum value of the plurality of first projection data sets in a temporal direction; and

a reconstruction unit which reconstructs volume data set for the object on the basis of the generated second projection data set.