CT Projection Data Contrast Enhancement via Synthetic Low-Energy Transformation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional CT imaging systems face challenges in enhancing contrast levels without increasing contrast or radiation dosage, particularly for non-spectral CT imaging systems.
Innovation Solution
The method involves modifying projection data based on the absorption behavior of materials at a selected energy, acquired at a higher energy, to simulate lower energy acquisition, and blending images reconstructed from these modified datasets to enhance contrast while reducing beam-hardening artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dual energy systems are used to enhance contrast levels, then contrast differentiation is improved, but device complexity and cost increase
Solution Approach 1:
The patent creates a virtual copy of low-energy projection data by mathematically transforming high-energy projection data using basis material decomposition and synthetic projection techniques. This copied data mimics the characteristics of actual low-energy acquisition without requiring physical low-energy x-ray sources, thereby achieving dual-energy contrast differentiation while maintaining single-energy system simplicity
Solution Approach 2:
The patent introduces basis material decomposition as an intermediary process that mediates between high-energy projection data and the desired low-energy image characteristics. By decomposing the high-energy data into basis materials and reconstructing synthetic projections, the system bridges the gap between single-energy acquisition and dual-energy imaging capabilities
2Measurement precision
If contrast dosage is increased to enhance contrast levels, then contrast visibility is improved, but patient exposure to contrast agents increases
Solution Approach 1:
The patent changes the energy parameter of the x-ray photons by mathematically transforming high-energy projection data into synthetic low-energy projections. This parameter transformation enhances the attenuation differences of contrast agents without requiring increased contrast dosage, as the contrast enhancement is achieved through energy domain transformation rather than increased contrast agent concentration
3Measurement precision
If radiation dosage is increased to enhance contrast levels, then signal-to-noise ratio is improved, but patient radiation exposure increases
Solution Approach 1:
The patent creates synthetic copies of low-energy projection data from high-energy acquisition, preserving the signal-to-noise characteristics of the original high-energy data while achieving the contrast enhancement typically associated with low-energy imaging. This eliminates the need to increase radiation dosage to improve signal quality
Solution Approach 2:
The patent replaces the mechanical approach of acquiring actual low-energy data with multiple x-ray sources or increasing radiation dosage with a computational approach. By using basis material decomposition and synthetic projection algorithms, the system achieves contrast enhancement through mathematical transformation rather than physical dose increase
4Device complexity
If single energy acquisition is used to simplify the system, then device complexity is reduced, but contrast differentiation capability deteriorates
Solution Approach 1:
The patent makes the single-energy CT system universally capable of producing both high-energy and low-energy style images through computational transformation. The system maintains its simple single-energy hardware configuration while gaining the functional capability of dual-energy imaging through basis material decomposition and synthetic projection techniques
Solution Approach 2:
The patent creates virtual low-energy projection data by copying and transforming the information contained in high-energy projection data. This synthetic data copying process preserves the simplicity of single-energy acquisition while achieving the contrast differentiation characteristics of low-energy imaging through mathematical transformation
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 allows for enhanced contrast in reconstructed images without increasing x-ray or contrast dosage, while minimizing beam-hardening artifacts, effectively mimicking dual-energy imaging benefits without the associated dose increases.
Implementation Method 1
technologies such as computed tomography (CT) use various physical principles, such as the differential transmission of x-rays through the target volume
Implementation Method 2
the attenuation of x-rays by such contrast agents depends on the energy of the x-rays. For conventional CT imaging systems that acquire projection data at a single energy, it may be difficult to distinguish contrast-filled regions
Data Source
AI summary
Methods and systems are provided for boosting the contrast levels in an image reconstructed from projection data acquired at a single energy. In one embodiment, a method comprises modifying projection data corresponding to a material based on an absorption behavior of the material at a selected energy, wherein the projection data is acquired at an energy higher than the selected energy. In this way, contrast levels may be enhanced in an image reconstructed from projection data acquired at a typical single energy as though the image were reconstructed from projection data acquired at a lower energy.