Guided Phase Zero Estimation for Ultrasound Elastography Displacement
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Solution Overview
Problem
Conventional ultrasound elastography methods for detecting tissue displacement in cancer detection face challenges in achieving high-quality strain images in real time due to high calculation requirements, phase aliasing, and neglecting lateral displacement, which affects contrast-to-noise ratio and frame rate.
Innovation Solution
The method employs guided phase zero estimation (GPZE) to rapidly determine displacement between down-sampled I/Q baseband echo signals, calculating longitudinal displacement and strain, thereby reducing computational load and improving image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If cross-correlation methods are used for displacement detection, then image quality is improved, but calculation amount increases and processing speed decreases
Solution Approach 1:
The patent segments the displacement detection process into two stages: first performing a coarse search using cross-correlation to identify the approximate displacement range, then performing fine measurement using phase shift methods within that restricted range. This segmentation allows the system to maintain measurement precision while significantly reducing the overall calculation amount and processing time.
Solution Approach 2:
The patent performs preliminary coarse displacement estimation using cross-correlation before conducting the final precise measurement. By预先 (in advance) determining the approximate displacement range, the system prepares the search space for the subsequent phase shift method, avoiding the need to perform computationally intensive cross-correlation calculations across the entire possible displacement range.
2Productivity
If phase shift methods are used for displacement detection, then processing speed is improved, but measurement precision deteriorates due to phase aliasing
Solution Approach 1:
The patent divides the measurement process into a coarse phase (using cross-correlation to establish the approximate displacement range) and a fine phase (using phase shift methods for precise measurement within the established range). This segmentation allows the phase shift method to operate in a restricted range where phase aliasing is minimized, thereby maintaining both speed and precision.
Solution Approach 2:
The patent performs preliminary coarse displacement estimation using cross-correlation to establish the search range before applying the phase shift method. This preliminary action provides the phase shift algorithm with prior knowledge of the displacement magnitude, enabling it to perform accurate measurements without suffering from phase aliasing that would occur if it had to search the entire possible range.
3Loss of information
If conventional displacement detection methods are used, then comprehensive displacement information is obtained, but calculation complexity increases
Solution Approach 1:
The patent segments the displacement detection into longitudinal and lateral components, applying different methods to each: cross-correlation for longitudinal displacement and phase shift for lateral displacement. This segmentation reduces calculation complexity by avoiding the application of computationally intensive cross-correlation to all displacement components while still capturing comprehensive displacement information.
Solution Approach 2:
The patent applies different detection methods to different displacement components based on their specific requirements: cross-correlation is applied to longitudinal displacement where high precision is needed, while phase shift is applied to lateral displacement where processing speed is more critical. This local quality approach optimizes the balance between information completeness and calculation complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach provides high-quality strain images while reducing calculation complexity, meeting clinical requirements in real time and being suitable for both small- and large-displacement cases, with enhanced signal-to-noise ratio and reduced phase aliasing.
Implementation Method 1
calculating a cross-correlation phase based on the cross-correlation phase calculation location; and calculating a longitudinal displacement based on the cross-correlation phase
Data Source
AI summary
Disclosed are a method and a device for detecting displacement in elastography. The method comprises: acquiring a target point, acquiring a cross-correlation phase calculation location of the target point in a second frame image; calculating a cross-correlation phase according to the cross-correlation phase calculation location; calculating a longitudinal displacement result according to the cross-correlation phase; and calculating a gradient of the displacement result to obtain a strain result. Through the elastography method and device, I/Q-channel echo baseband signals, obtained by downsampling, of two frames before and after compression are acquired, displace information between the two frames is rapidly detected by guiding phase estimation, and axial gradient calculation is performed to obtain strain information, which can not only obtain a strain image of high quality but also reduce the calculation amount, thereby satisfying the clinical real-time requirement.