Super-resolution flow field reconstruction method and device thereof
Disclosed is a super-resolution flow field reconstruction method, including: superimposing a plurality of frames of contrast-enhanced ultrasound images that are in one time interval and each of which includes images of a plurality of microbubbles, to obtain a superimposed image including a plurality of microbubble trajectories of the plurality of microbubbles; performing straight line fitting on the plurality of microbubble trajectories, to obtain a plurality of microbubble trajectory straight lines of the plurality of microbubbles, respectively; determining directions and velocities of instantaneous movements of the plurality of microbubbles in the time interval; and reconstructing a super-resolution flow field. This method avoids localization and tracking process of the plurality of moving microbubbles, overcomes the limitations of current ultrasound super-resolution imaging strategies under the impact of motion artifacts and low signal-to-noise-ratio, and improving precision and efficiency of super-resolution flow field reconstruction.
1. A super-resolution flow field reconstruction method, comprising:
superimposing a plurality of frames of contrast-enhanced ultrasound images that are in one time interval and each of which comprises images of a plurality of microbubbles, to obtain a superimposed image comprising a plurality of microbubble trajectories of the plurality of microbubbles;
performing straight line fitting on the plurality of microbubble trajectories, to obtain a plurality of microbubble trajectory straight lines of the plurality of microbubbles, respectively;
determining, based on directions and lengths of the plurality of microbubble trajectory straight lines of the plurality of microbubbles and a quantity of superimposed frames and a frame rate of the plurality of frames of contrast-enhanced ultrasound images, directions and velocities of instantaneous movements of the plurality of microbubbles in the time interval; and
reconstructing a super-resolution flow field based on directions and velocities of instantaneous movements of the plurality of microbubbles in each of different time intervals; wherein
the superimposing a plurality of frames of contrast-enhanced ultrasound images that are in one time interval and each of which comprises images of a plurality of microbubbles, to obtain a superimposed image comprising a plurality of microbubble trajectories of the plurality of microbubbles comprises:
performing registration on the plurality of frames of contrast-enhanced ultrasound images that are in the one time interval and each of which comprises the images of the plurality of microbubbles, to obtain a plurality of frames of registered contrast-enhanced ultrasound images each comprising the images of the plurality of microbubbles; and
superimposing the plurality of frames of registered contrast-enhanced ultrasound images that are in the one time interval and each of which comprises the images of the plurality of microbubbles, to obtain the superimposed image comprising the plurality of microbubble trajectories of the plurality of microbubbles.
2. The super-resolution flow field reconstruction method according to claim 1 , wherein the performing registration on the plurality of frames of contrast-enhanced ultrasound images that are in the one time interval and each of which comprises the images of the plurality of microbubbles, to obtain a plurality of frames of registered contrast-enhanced ultrasound images each comprising the images of the plurality of microbubbles comprises:
performing, by using a multi-scale registration method, registration on the plurality of frames of contrast-enhanced ultrasound images that are in the one time interval and each of which comprises the images of the plurality of microbubbles, to obtain the plurality of frames of registered contrast-enhanced ultrasound images each comprising the images of the plurality of microbubbles.
3. The super-resolution flow field reconstruction method according to claim 2 , wherein the multi-scale registration method comprises global decomposition, local decomposition, and detail decomposition according to decomposition scale.
4. The super-resolution flow field reconstruction method according to claim 1 , wherein the superimposing a plurality of frames of contrast-enhanced ultrasound images that are in one time interval and each of which comprises images of a plurality of microbubbles, to obtain a superimposed image comprising a plurality of microbubble trajectories of the plurality of microbubbles comprises:
superimposing a plurality of consecutive frames of contrast-enhanced ultrasound images that are in the one time interval and each of which comprises the images of the plurality of microbubbles, to obtain the superimposed image comprising the plurality of microbubble trajectories of the plurality of microbubbles.
5. The super-resolution flow field reconstruction method according to claim 2 , wherein the superimposing a plurality of consecutive frames of contrast-enhanced ultrasound images that are in the one time interval and each of which comprises the images of the plurality of microbubbles, to obtain the superimposed image comprising the plurality of microbubble trajectories of the plurality of microbubbles comprises:
superimposing two, three, or four consecutive frames of contrast-enhanced ultrasound images that are in the one time interval and each of which comprises the images of the plurality of microbubbles, to obtain the superimposed image comprising the plurality of microbubble trajectories of the plurality of microbubbles.
6. The super-resolution flow field reconstruction method according to claim 1 , wherein the different time intervals comprise:
different time intervals that comprise a same quantity of frames and whose start frames have a same interval.
7. The super-resolution flow field reconstruction method according to claim 1 , wherein the superimposing a plurality of frames of contrast-enhanced ultrasound images that are in one time interval and each of which comprises images of a plurality of microbubbles, to obtain a superimposed image comprising a plurality of microbubble trajectories of the plurality of microbubbles comprises:
superimposing the plurality of frames of contrast-enhanced ultrasound images that are in the one time interval and each of which comprises the images of the plurality of microbubbles, to obtain a superimposed image comprising a plurality of preliminary microbubble trajectories of the plurality of microbubbles; and
separately performing skeleton extraction on the plurality of preliminary microbubble trajectories in the superimposed image of the plurality of preliminary microbubble trajectories of the plurality of microbubbles, to obtain the plurality of microbubble trajectories.
8. The super-resolution flow field reconstruction method according to claim 7 , wherein the separately performing skeleton extraction on the plurality of preliminary microbubble trajectories in the superimposed image of the plurality of preliminary microbubble trajectories of the plurality of microbubbles comprises:
separately performing, by using an iterative erosion algorithm, the skeleton extraction on the plurality of preliminary microbubble trajectories in the superimposed image.
9. The super-resolution flow field reconstruction method according to claim 7 , wherein the separately performing skeleton extraction on the plurality of preliminary microbubble trajectories in the superimposed image of the plurality of preliminary microbubble trajectories of the plurality of microbubbles comprises:
separately performing, by using a circumscribed rectangle-maximum grayscale integral axis extraction algorithm, the skeleton extraction on the plurality of preliminary microbubble trajectories in the superimposed image.
10. The super-resolution flow field reconstruction method according to claim 1 , wherein the determining, based on directions and lengths of the plurality of microbubble trajectory straight lines of the plurality of microbubbles and a quantity of superimposed frames and a frame rate of the plurality of frames of contrast-enhanced ultrasound images, directions and velocities of instantaneous movements of the plurality of microbubbles in the time interval comprises:
determining, based on the directions of the plurality of microbubble trajectory straight lines of the plurality of microbubbles, the directions of instantaneous movements of the plurality of microbubbles in the time interval; and
determining, based on a product of the frame rate and a ratio of the lengths of the microbubble trajectory straight lines of the plurality of microbubbles to the quantity of superimposed frames of the plurality of frames of contrast-enhanced ultrasound images, the velocities of instantaneous movements of the plurality of microbubbles in the time interval.
11. The super-resolution flow field reconstruction method according to claim 1 , wherein each microbubble trajectory straight line of each microbubble in the plurality of microbubble trajectory straight lines of the plurality of microbubbles comprises at least one pixel coordinate; and
the reconstructing a super-resolution flow field based on directions and velocities of instantaneous movements of the plurality of microbubbles in each of different time intervals comprises:
determining, based on the directions and velocities of instantaneous movements of the plurality of microbubbles in each of the different time intervals, directions and velocities of instantaneous movements of the plurality of microbubbles, in each of the different time intervals, corresponding to a plurality of pixel coordinates; and
reconstructing the super-resolution flow field based on the directions and velocities of instantaneous movements of the plurality of microbubbles, in each of the different time intervals, corresponding to the plurality of pixel coordinates.
12. The super-resolution flow field reconstruction method according to claim 11 , wherein a plurality of microbubble trajectories of the each microbubble comprise same pixel coordinates; and
the reconstructing the super-resolution flow field comprises:
calculating a frequency of occurrence of each of directions and velocities of instantaneous movements corresponding to the same pixel coordinates of the each microbubble, and selecting a direction and a velocity, having the highest frequency of occurrence, of instantaneous movements to reconstruct the super-resolution flow field.
13. The super-resolution flow field reconstruction method according to claim 11 , wherein a plurality of microbubble trajectories of the each microbubble comprise same pixel coordinates; and
the reconstructing the super-resolution flow field comprises:
calculating an average value of each of directions and velocities of instantaneous movements corresponding to the same pixel coordinates of the each microbubble, to reconstruct the super-resolution flow field.
14. The super-resolution flow field reconstruction method according to claim 11 , wherein a plurality of microbubble trajectories of the each microbubble comprise same pixel coordinates; and
the reconstructing the super-resolution flow field comprises:
calculating a maximum value of each of directions and velocities of instantaneous movements corresponding to the same pixel coordinates of the each microbubble to reconstruct the super-resolution flow field.
15. The super-resolution flow field reconstruction method according to claim 1 , wherein the performing straight line fitting on the plurality of microbubble trajectories, to obtain a plurality of microbubble trajectory straight lines of the plurality of microbubbles, respectively comprises:
performing, by using a Hough transform-based straight line detection method, straight line fitting on the plurality of microbubble trajectories, to obtain the plurality of microbubble trajectory straight lines of the plurality of microbubbles, respectively.
16. An electronic device, comprising:
a processor; and
a memory, wherein the memory stores computer program instructions, and when the computer program instructions are run by the processor, the processor is enabled to perform the super-resolution flow field reconstruction method according to claim 1 .
17. The electronic device according to claim 16 , wherein the superimposing a plurality of frames of contrast-enhanced ultrasound images that are in one time interval and each of which comprises images of a plurality of microbubbles, to obtain a superimposed image comprising a plurality of microbubble trajectories of the plurality of microbubbles comprises:
superimposing a plurality of consecutive frames of contrast-enhanced ultrasound images that are in the one time interval and each of which comprises the images of the plurality of microbubbles, to obtain the superimposed image comprising the plurality of microbubble trajectories of the plurality of microbubbles.
18. A non-transitory computer-readable storage medium storing computer program instructions for executing the super-resolution flow field reconstruction method according to claim 1 .