Medical image processing apparatus

1. A medical image processing apparatus comprising processing circuitry configured to:

acquire volume data indicating a state of a three-dimensional region including a mass portion and blood vessels derived from the mass portion in a subject;

specify a region corresponding to the mass portion and the blood vessels in the volume data as a region of interest;

identify the mass portion, a center point of the mass portion, and each of the blood vessels in the region of interest;

assign a different display mode to at least one of the mass portion and the blood vessels;

identify a mass region representing the mass portion and a blood vessel region corresponding to the blood vessels based on a region growing process for extending a region from the center point of the mass portion in the volume data by iteratively appending to the center point of the mass portion a mass voxel of a connected region that belongs to the mass portion by determining that the mass voxel has a voxel value within a range of setting information for the mass portion;

iteratively extending the region by the region growing process by performing a thinning process for each iteration of the extending the region by the region growing process;

identify whether the region extends in less than all directions based on a number of voxels corresponding to the mass region and the blood vessel region among all neighboring voxels;

identify, when the region extends in less than all directions, a blood vessel voxel that is thinned by the thinning process in an image of a blood vessel as a center line of the blood vessel, the blood vessel extending in directions in which the region extends in the blood vessel region;

determine whether there is a branch in the blood vessel by determining that there is a branch in the center line of the blood vessel; and

end the region growing process when there is a branch in the blood vessel.

2. The medical image processing apparatus of claim 1 , wherein the processing circuitry is further configured to create a list of the blood vessels identified.

3. The medical image processing apparatus of claim 2 , wherein the processing circuitry is further configured to obtain at least one of length, diameter, and contrast agent concentration with respect to the each of the blood vessels identified, and display in the list the at least one of length, diameter, and contrast agent concentration obtained.

4. The medical image processing apparatus of claim 1 , wherein the processing circuitry is further configured to:

generate a two-dimensional image including the mass portion and the blood vessels based on the volume data;

receive a designated point for the mass portion in the two-dimensional image; and

identify substantially the center point of the mass portion based on a positional relationship between the two-dimensional image and the volume data and a position of the designated point in the volume data.

5. The medical image processing apparatus of claim 1 , wherein the processing circuitry is further configured:

store a threshold to identify a voxel corresponding to the mass portion or a blood vessel in the region growing;

obtain a value indicating a change in voxel value of neighboring voxels searched in the region growing; and

identify the voxel corresponding to the mass portion or the blood vessel based on the threshold and the value indicating a change.

6. The medical image processing apparatus of claim 1 , wherein the processing circuitry is further configured to obtain a departure angle of the each of the blood vessels from the mass portion,

wherein the medical image processing apparatus further comprises a storage configured to store display mode information corresponding to the departure angle, and wherein the processing circuitry is further configured to:

retrieve, from the storage, the display mode information corresponding to the departure angle obtained; and

assign the different display mode to a blood vessel region corresponding to the blood vessel having the departure angle based on the display mode information.

7. The medical image processing apparatus of claim 6 , wherein the processing circuitry is further configured to specify a base of the blood vessel on a side of the mass portion in the region of interest, and obtain as the departure angle an angle between part of the mass portion continuous with the base and the base.

8. The medical image processing apparatus of claim 7 , wherein the processing circuitry is further configured to specify beginning of the blood vessel on the side of the mass portion and end thereof in the region of interest, and obtain as the departure angle an angle between part of the mass portion near the beginning and a line segment connecting the beginning and the end.

9. The medical image processing apparatus of claim 6 , wherein the processing circuitry is further configured to:

identify a branch between the blood vessel region and the mass portion; and

obtain a three-dimensional angle of a line connecting the branch and a substantial center of the mass portion as the departure angle.

10. The medical image processing apparatus of claim 6 , wherein the processing circuitry is further configured to:

compare departure angles of the blood vessels to classify the blood vessels; and

vary the display mode according to the blood vessels classified.

11. The medical image processing apparatus of claim 6 , wherein the processing circuitry is further configured to:

obtain a difference between a first departure angle of one blood vessel and a second departure angle of another blood vessel; and

specify the blood vessel corresponding to the first departure angle as an inflow blood vessel to the mass portion, and the other blood vessel as an outflow blood vessel, when the difference is within a predetermined range.

12. The medical image processing apparatus of claim 6 , wherein the processing circuitry is further configured to:

compare departure angles of the blood vessels to specify a first blood vessel and a second blood vessel which extend in substantially opposite directions; and

specify one of the first blood vessel and the second blood vessel as an inflow blood vessel and another as an outflow blood vessel based on the departure angles thereof.

13. The medical image processing apparatus of claim 12 , wherein the processing circuitry is further configured to display the inflow blood vessel and the outflow blood vessel in different colors.

14. The medical image processing apparatus of claim 1 , wherein the processing circuitry is further configured to display the mass portion and the blood vessels in at least either one of different color and different transparency from other parts as the different display mode.

15. The medical image processing apparatus of claim 1 , wherein the processing circuitry is further configured to extract a contour of the mass portion and the blood vessels and highlight the contour to display at least one of blood vessel regions each corresponding to one of the blood vessels in the different display mode.