Energy-Subtraction Radiography for Moving-Object Artifact Reduction
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Solution Overview
Problem
When digital subtraction angiography (DSA) is applied using images generated by a flat panel detector (FPD), artifacts are created due to the presence of moving objects such as stents or calcified substances in the mask image, leading to inaccuracies in the difference between the live and mask images.
Innovation Solution
A radiation imaging system and method that utilizes time-division driving of radiation energies, employing a two-dimensional detector to capture images at different energies within a single frame, followed by energy subtraction processing to separate images of bone and soft tissue, and then applying digital subtraction angiography to generate artifact-free difference images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If digital subtraction angiography is applied using images generated by FPD, then blood vessel imaging capability is improved, but artifact creation increases due to moving objects in mask image
Solution Approach 1:
The imaging process is segmented into multiple energy acquisitions (first energy and second energy) within a single frame period. By separating the energy acquisition timing and processing them differently, the patent reduces artifacts caused by moving objects in the mask image while maintaining blood vessel imaging capability.
Solution Approach 2:
The patent employs periodic acquisition of images at different energies within a frame period, using timing control to alternately capture first energy images and second energy images. This periodic action allows synchronization with the imaging sequence to minimize artifacts from moving objects.
2Adaptability or versatility
If images at different energies are acquired at different times, then energy subtraction processing capability is improved, but moving objects cause misalignment between images
Solution Approach 1:
The patent merges multiple energy acquisitions into a single frame period, capturing both first energy and second energy images within the same frame. This combining approach ensures temporal synchronization and eliminates misalignment issues caused by moving objects between separate acquisitions.
Solution Approach 2:
The patent adds an energy dimension to the imaging process by acquiring images at multiple energy levels within a single frame. This dimensional expansion allows energy subtraction processing while maintaining spatial alignment through simultaneous acquisition timing.
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 significantly reduces the creation of artifacts in the generated images, allowing for accurate diagnosis of blood vessels by imaging only the contrast agent, even in the presence of moving objects, by using time-division energy subtraction and DSA processing.
Implementation Method 1
a radiation generation apparatus that generates radiation
Implementation Method 2
a radiation imaging apparatus that images a subject by use of the generated radiation
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
An imaging control apparatus obtains a plurality of images at different radiation energies, generates an energy subtraction image by performing energy subtraction processing using the plurality of images, and generates a difference image between a mask image that is based on a plurality of energy subtraction images generated in a past and a live image that is based on a current energy subtraction image.