Ultrasonic image processing apparatus, ultrasonic diagnostic apparatus, and ultrasonic image processing method

1 . An ultrasonic image processing apparatus, comprising:

processing circuitry configured to:

acquire volume data based on ultrasonic signals collected by 3D color doppler mode, wherein each voxel value of the volume data includes at least a value of a velocity of a fluid and a value of a power representing an intensity of echo signals of the fluid;

generate a velocity rendering image by volume rendering the volume data using an opacity map in which a relationship between an opacity of the voxel and both the velocity and the power is defined,

wherein the processing circuitry is further configured to:

generate first opacity data that defines the relationship between the velocity and the opacity, and second opacity data that defines the relationship between the power and the opacity; and

generate the opacity map using the first opacity data and the second opacity data.

2 . The ultrasonic image processing apparatus according to claim 1 , wherein the processing circuitry is further configured to;

generate a velocity-based opacity map by determining, for each voxel, the opacity corresponding to the value of the velocity included in each voxel of the volume data with reference to the first opacity data,

generate a power-based opacity map by determining, for each voxel, the opacity corresponding to the value of the power contained in each voxel of the volume data with reference to the second opacity data, and

generate the opacity map by multiplying the velocity-based opacity map and the power-based opacity map for each voxel.

3 . The ultrasonic image processing apparatus according to claim 1 , further comprising a user interface configured to allow a user to specify a threshold index that defines a lower limit of the velocity to be displayed in the velocity rendering image and an opacity index that defines the relationship between the velocity and the opacity used for the volume rendering,

wherein the processing circuitry is further configured to generate the first opacity data and the second opacity data based on at least one of the threshold index and the opacity index specified via the user interface.

4 . The ultrasonic image processing apparatus according to claim 3 , wherein, when changing the first opacity data and the second opacity data based on the at least one of the threshold index and the opacity index, the processing circuitry is further configured to change the second opacity data preferentially over the first opacity data.

5 . The ultrasonic image processing apparatus according to claim 3 , wherein the processing circuitry is further configured to:

when the threshold index set via the user interface is a predetermined value or less, change the threshold value in the second opacity data based on the set threshold index, while leaving the threshold value in the first opacity data unchanged; and

when the threshold index set via the user interface is greater than the predetermined value, change the threshold in the first opacity data based on the difference between the set threshold index and the predetermined value, while leaving the threshold value in the second opacity data unchanged.

6 . The ultrasonic image processing apparatus according to claim 3 , wherein the processing circuitry is further configured to:

when the opacity index set via the user interface is a predetermined value or less, change the opacity in the second opacity data based on the set opacity index, while leaving the opacity in the first opacity data unchanged; and

when the opacity index set via the user interface is greater than the predetermined value, change the opacity in the first opacity data based on the difference between the set opacity index and the predetermined value, while leaving the opacity in the second opacity data unchanged.

7 . An ultrasonic image processing apparatus, comprising:

processing circuitry configured to:

acquire volume data based on ultrasonic signals collected by 3D color doppler mode, wherein each voxel value of the volume data includes at least a value of a velocity of a fluid and a value of a power representing an intensity of echo signals of the fluid;

generate a velocity rendering image by volume rendering the volume data using an opacity map in which a relationship between an opacity of the voxel and both the velocity and the power is defined,

wherein the processing circuitry is further configured to:

generate two-dimensional opacity data in which the relationship between the opacity and both the velocity and the power is defined; and

generate the opacity map using the two-dimensional opacity data.

8 . The ultrasonic image processing apparatus according to claim 7 , wherein the processing circuitry is further configured to:

determine, for each voxel, the opacity corresponding to the value of the velocity and the value of the power included in each voxel of the volume data by referring to the two-dimensional opacity data; and

generate the opacity map using the determined opacity for each voxel.

9 . The ultrasonic image processing apparatus according to claim 7 , further comprising a user interface configured to allow a user to specify a threshold index that defines a lower limit of the velocity to be displayed in the velocity rendering image and an opacity index that defines the relationship between the velocity and the opacity used for the volume rendering,

wherein the processing circuitry is further configured to generate the two-dimensional opacity data based on at least one of the threshold index and the opacity index specified via the user interface.

10 . The ultrasonic image processing apparatus according to claim 9 , wherein, when changing the two-dimensional opacity data based on the at least one of the threshold index and the opacity index, the processing circuitry is further configured to change the second opacity data preferentially over the first opacity data.

11 . An ultrasonic diagnostic apparatus, comprising the ultrasonic image processing apparatus according to claim 1 .

12 . An ultrasonic image processing method, comprising:

acquiring volume data based on ultrasonic signals collected by 3D color doppler mode, wherein each voxel value of the volume data includes at least a value of a velocity of a fluid and a value of a power representing an intensity of echo signals of the fluid;

generating a velocity rendering image by volume rendering the volume data using an opacity map in which a relationship between the opacity of the voxel and both the velocity and the power is defined, wherein the method further comprises

generating first opacity data that defines the relationship between the velocity and the opacity, and second opacity data that defines the relationship between the power and the opacity; and

generating the opacity map using the first opacity data and the second opacity data.

13 . An ultrasonic image processing method, comprising:

acquiring volume data based on ultrasonic signals collected by 3D color doppler mode, wherein each voxel value of the volume data includes at least a value of velocity of a fluid and a value of a power representing an intensity of echo signals of the fluid;

generating a velocity rendering image by volume rendering the volume data using an opacity map in which a relationship between the opacity of the voxel and both the velocity and the power is defined;

generate two-dimensional opacity data in which the relationship between the opacity and both the velocity and the power is defined; and

generate the opacity map using the two-dimensional opacity data.