Ultrasound diagnostic apparatus, medical image processing apparatus, and medical image processing method
An ultrasound diagnostic apparatus according to an embodiment includes processing circuitry. The processing circuitry derives a predefined image evaluation parameter with respect to a plurality of two-dimensional ultrasound images obtained by an ultrasound probe. Based on the derivation results of the image evaluation parameter, the processing circuitry selects a two-dimensional ultrasound image for registration purpose from among the plurality of two-dimensional ultrasound images. The processing circuitry performs image registration of a three-dimensional medical image and the two-dimensional medical image for registration purpose.
1 . An ultrasound diagnostic apparatus, comprising:
processing circuitry configured to:
derive a predefined image evaluation parameter with respect to a plurality of two-dimensional ultrasound images obtained by an ultrasound probe;
select a two-dimensional ultrasound image for registration purposes from among the plurality of two-dimensional ultrasound images, based on derivation results of the image evaluation parameter; and
perform image registration of a three-dimensional medical image and the two-dimensional ultrasound image for registration purposes,
wherein, as the image evaluation parameter, at least one of a landmark, a texture metric, an orthogonality metric, a coverage, or a Doppler blood flow image is used.
2 . The ultrasound diagnostic apparatus according to claim 1 , wherein
the processing circuitry is further configured to detect a landmark from the two-dimensional ultrasound image for registration purposes and from the three-dimensional medical image, and
based on a landmark in the three-dimensional medical image and based on the corresponding landmark in the two-dimensional ultrasound image for registration purposes, the processing circuitry is further configured to perform the image registration.
3 . The ultrasound diagnostic apparatus according to claim 1 , wherein the processing circuitry is further configured to display the derivation results along with the two-dimensional ultrasound images on a display.
4 . The ultrasound diagnostic apparatus according to claim 3 , wherein the processing circuitry is further configured to display the derivation results in different forms according to degrees of recommendation.
5 . The ultrasound diagnostic apparatus according to claim 1 , wherein the processing circuitry is further configured to display, in a highlighted manner, a particular two-dimensional ultrasound image for which the derivation result exceeds a predetermined threshold value.
6 . The ultrasound diagnostic apparatus according to claim 1 , wherein the processing circuitry is further configured to automatically select, as the two-dimensional ultrasound image for registration purposes, a particular two-dimensional ultrasound image for which the derivation result exceeds a predetermined threshold value.
7 . The ultrasound diagnostic apparatus according to claim 1 , wherein, when the texture metric is used as the image evaluation parameter, the processing circuitry is further configured to select the two-dimensional ultrasound image including a greater number of texture structures as the two-dimensional ultrasound image for registration purposes.
8 . The ultrasound diagnostic apparatus according to claim 1 , wherein, when the orthogonality metric is used as the image evaluation parameter, the processing circuitry is further configured to select particular two-dimensional ultrasound images, from among the plurality of two-dimensional ultrasound images, having scanning directions orthogonally closer, as the two-dimensional ultrasound images for registration purposes.
9 . The ultrasound diagnostic apparatus according to claim 1 , wherein, when the coverage is used as the image evaluation parameter, the processing circuitry is further configured to select, as the two-dimensional ultrasound image for registration purposes from among the plurality of two-dimensional ultrasound images, a particular two-dimensional ultrasound image that forms a closed region in three-dimensional space to account for a large portion of entire region of interest.
10 . The ultrasound diagnostic apparatus according to claim 1 , wherein, when the Doppler image is used as the image evaluation parameter, the processing circuitry is further configured to select a particular two-dimensional ultrasound image including blood flow information as the two-dimensional ultrasound image for registration purpose.
11 . The ultrasound diagnostic apparatus according to claim 1 , wherein, when a plurality of image evaluation parameters is used, the processing circuitry is further configured to select the two-dimensional ultrasound image for registration purposes based on weighting coefficients assigned to the plurality of image evaluation parameters.
12 . The ultrasound diagnostic apparatus according to claim 1 , wherein the processing circuitry is further configured to display normalized numerical values as the derivation results.
13 . The ultrasound diagnostic apparatus according to claim 1 , wherein the three-dimensional medical image is either one of a three-dimensional ultrasound image, a three-dimensional computer tomography image, and a three-dimensional magnetic resonance image.
14 . The ultrasound diagnostic apparatus according to claim 2 , wherein the landmark represents a body part having anatomically distinctive features.
15 . The ultrasound diagnostic apparatus according to claim 2 , wherein
the processing circuitry is further configured to generate a conversion parameter indicating a correspondence relationship between a landmark in a three-dimensional medical image and corresponding landmark in a particular two-dimensional ultrasound image, and
the processing circuitry is further configured to perform the registration based on the conversion parameter.
16 . The ultrasound diagnostic apparatus according to claim 1 , wherein, the processing circuitry is further configured to select an additional two-dimensional ultrasound image, among the plurality of two-dimensional ultrasound images, for registration purposes, and the processing circuitry is further configured to perform the registration using the selected two-dimensional ultrasound images and the three-dimensional medical image.
17 . The ultrasound diagnostic image according to claim 1 , wherein the processing circuitry is further configured to select an additional two-dimensional ultrasound image, among the plurality of two-dimensional ultrasound images, for registration purposes, and
the processing circuitry is further configured to reconstruct a three-dimensional medical image based on the selected two-dimensional ultrasound images and perform the registration using the reconstructed three-dimensional medical image and the three-dimensional medical image.
18 . The ultrasound diagnostic apparatus according to claim 17 , wherein the processing circuitry is further configured to:
select, as the selected two-dimensional ultrasound images, a reference two-dimensional ultrasound image, which represents a particular two-dimensional ultrasound image having the image evaluation parameter to be largest, and a predetermined number of two-dimensional ultrasound images arranged before and after the reference two-dimensional ultrasound image,
with respect to the derivation results of the image evaluation parameter of the selected two-dimensional ultrasound images, assign weights in such a way that, farther a two-dimensional ultrasound image is from the reference two-dimensional ultrasound image, smaller is assigned weight,
derive an overall image evaluation parameter of the selected two-dimensional ultrasound images based on the derivation results and the weights, and
when the overall image evaluation parameter is equal to or greater than a setting image evaluation parameter, select the selected two-dimensional ultrasound images as the two-dimensional ultrasound images for registration purpose.
19 . The ultrasound diagnostic apparatus according to claim 18 , wherein, when a texture metric is used as the image evaluation parameter, the image evaluation parameter is based on at least one of a luminance gradient and a luminance difference in the selected two-dimensional ultrasound images.
20 . A medical image processing apparatus, comprising:
processing circuitry configured to:
derive a predefined image evaluation parameter with respect to a plurality of two-dimensional ultrasound images obtained by an ultrasound probe;
select a two-dimensional ultrasound image for registration purposes from the plurality of two-dimensional ultrasound images, based on derivation results of the image evaluation parameter; and
perform image registration of a three-dimensional medical image and the two-dimensional ultrasound image for registration purposes,
wherein, as the image evaluation parameter, at least one of a landmark, a texture metric, an orthogonality metric, a coverage, or a Doppler blood flow image is used.
21 . A medical image processing method, comprising:
deriving a predefined image evaluation parameter with respect to a plurality of two-dimensional ultrasound images obtained by an ultrasound probe;
selecting, based on derivation results of the image evaluation parameter, a two-dimensional ultrasound image for registration purposes from the plurality of two-dimensional ultrasound images; and
performing image registration of a three-dimensional medical image and the two-dimensional ultrasound image for registration purposes,
wherein, as the image evaluation parameter, at least one of a landmark, a texture metric, an orthogonality metric, a coverage, or a Doppler blood flow image is used.