CT System ED and EI Detector Data Recovery
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Solution Overview
Problem
Computed tomography (CT) systems with energy discriminating (ED) detectors face limitations in high-flux applications due to photon counting rate limitations, leading to loss of data and image artifacts, especially when operating at different kilovoltage potentials, which restricts effective field of view and material decomposition accuracy.
Innovation Solution
A CT system that employs a combination of energy discriminating (ED) and energy integrating (EI) detectors, where the EI detector measures and patches missing data for the ED detector by using a correlation function between projections acquired at different spectra, enabling effective recovery of missing projection data and improving material decomposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If energy discriminating (ED) detectors are used to enable material decomposition, then material composition information can be obtained, but data loss and image artifacts occur due to photon counting rate limitations in high-flux applications
Solution Approach 1:
An energy integrating (EI) detector is introduced as an intermediary component to capture complete projection data that is lost by the ED detector due to photon saturation. The EI detector serves as a mediator that records all incident photons regardless of energy, providing a backup data source that complements the energy-resolved but flux-limited ED detector measurements.
Solution Approach 2:
The system merges the capabilities of two different detector types: the ED detector that provides energy discrimination for material decomposition, and the EI detector that provides complete flux measurement without saturation. By combining their respective strengths, the system achieves both material decomposition accuracy and data completeness in high-flux conditions.
2Measurement precision
If multiple distinct incident energy spectra are used for material decomposition, then material composition information improves, but the system complexity and data processing requirements increase
Solution Approach 1:
The energy integrating detector performs multiple functions: it serves as a backup for flux measurement, provides total intensity data for normalization, and enables reconstruction of missing energy-bin data. This multi-functionality reduces the need for additional specialized components while maintaining material decomposition capabilities.
3Measurement precision
If different kilovoltage potentials are used to create distinct spectra, then material decomposition capability is achieved, but the effective field of view is restricted due to missing data in secondary detector
Solution Approach 1:
The system creates a complete data copy at the EI detector that captures all photons across the full field of view without energy-bin saturation. This complete data copy is then used to reconstruct missing information in the ED detector's energy bins, effectively extending the usable field of view to match the geometric FOV of the scanner.
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 enhances data recovery and reduces image artifacts, allowing for accurate material decomposition and improved imaging performance even at high flux conditions, by utilizing the ED and EI detectors in tandem to compensate for photon saturation and incomplete data sets.
Implementation Method 1
an exemplary detector that comprises an energy discriminating (ED) detector and an energy integrating (EI) detector... Each scintillator of a scintillator array converts x-rays to light energy
Implementation Method 2
Each photodiode detects the light energy and generates a corresponding electrical signal
Data Source
AI summary
A CT system in an example comprises one or more high frequency electromagnetic energy sources, a detection assembly, a data acquisition system (DAS), and a computer. The one or more high frequency electromagnetic energy sources emit one or more beams of high frequency electromagnetic energy toward an object to be imaged. The detection assembly is capable of measuring a plurality of projection data at a same projection path that corresponds to a plurality of distinct incident energy spectra. The detection assembly comprises one or more energy discriminating (ED) detectors and/or one or more energy integration (EI) detectors that receive high frequency electromagnetic energy emitted by the one or more high frequency electromagnetic energy sources. The data acquisition system (DAS) is operably connected to the one or more ED detectors and/or the one or more EI detectors. The computer is operably connected to the DAS.