Spectral CT Imaging Correction for K-Edge Contrast Distortion
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Solution Overview
Problem
Conventional CT scans with administered K-edge materials distort anatomical images due to displacement of native radiation-absorbing materials, making it difficult to differentiate between less dense tissue and contrast material, leading to erroneous interpretations.
Innovation Solution
A system and method that generates estimated native image data by using a correction factor to account for displaced native materials during spectral imaging procedures, allowing for the generation of images that resemble those taken without contrast agents, by administering a contrast agent with known K-edge energy and performing spectral imaging to determine the concentration and attenuation of displaced materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If K-edge material is administered to enhance spectral imaging capability, then spectral information and elemental composition detection are improved, but anatomical image accuracy deteriorates due to displacement of native radiation-absorbing material
Solution Approach 1:
The patent segments the imaging process into separate spectral bins (e.g., low energy and high energy photons) and processes each bin independently. By dividing the energy spectrum into discrete ranges, the system can analyze attenuation characteristics at different energy levels separately, enabling accurate material decomposition while maintaining anatomical fidelity in the reconstructed images.
Solution Approach 2:
The patent changes the energy parameter by acquiring and processing data at multiple energy levels (spectral imaging). By analyzing attenuation at different photon energy ranges and applying material decomposition algorithms, the system can distinguish between contrast material and native tissue based on their different spectral signatures, thereby recovering accurate anatomical attenuation values despite the presence of contrast agents.
2Illumination intensity
If contrast material is used to highlight vascular structures, then vascular visibility is improved, but differentiation between contrast and tissue density becomes difficult
Solution Approach 1:
The patent uses spectral information as an intermediary to mediate between contrast material enhancement and anatomical structure preservation. By analyzing the energy-dependent attenuation characteristics of photons, the system can identify and separate the contribution of contrast material from native tissue, effectively using spectral data as a mediator to recover accurate anatomical information while maintaining vascular visibility.
Solution Approach 2:
The patent replaces conventional single-energy attenuation-based imaging with spectral imaging that utilizes energy-resolved detection. Instead of relying solely on attenuation magnitude, the system substitutes in the use of energy spectrum analysis and material decomposition algorithms to distinguish between contrast and tissue, thereby preserving anatomical information that would otherwise be lost.
3Shape
If conventional CT imaging is used to maintain anatomical structure visibility, then anatomical detail is preserved, but spectral information is lost due to energy integration
Solution Approach 1:
The patent segments the energy spectrum into multiple discrete bins or ranges, allowing simultaneous preservation of anatomical structure visibility through spatial resolution and spectral information through energy resolution. Each energy bin is processed independently to maintain both structural detail and spectral characteristics.
Solution Approach 2:
The patent adds the energy dimension to conventional spatial imaging by performing spectral imaging. Instead of integrating over all energies, the system resolves the energy dimension and processes data in the energy domain, thereby preserving both anatomical structure (spatial dimension) and spectral characteristics (energy dimension) simultaneously through multi-dimensional data acquisition and reconstruction.
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
The system effectively corrects for the distortion caused by contrast agents, producing images with attenuation values more similar to native images, thereby improving diagnostic accuracy by distinguishing between tissue density and contrast material presence.
Implementation Method 1
The x-ray tube rotates around an examination region located between the x-ray tube and the one or more detectors and emits polychromatic radiation
Implementation Method 2
the absorption of a photon by a material is dependent on the energy of the photon traversing the material
Implementation Method 3
A spectral CT scanner includes an energy resolving detector that produces an electrical signal indicative of the energy of a detected photon
Implementation Method 4
high-Z elements tend to attenuate photons to a much higher extent above a particular energy, the K-edge energy of the given element, relative to attenuating photons just below the K-edge energy. The discontinuity in the attenuation can be detected.
Data Source
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AI summary
A system includes an image estimator (128) that generates estimated native image data from data acquired when a K-edge material is present in a scanned region during data acquisition, wherein the estimated native image data is indicative of native image data generated from data acquired when the K-edge material is not present in the scanned region during the data acquisition.