Dual-Spectrum CT Voltage Modulation for Image Registration
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Solution Overview
Problem
Conventional dual energy CT scanning requires separate scans at different kVp levels, leading to mis-registration due to patient motion and cone angle effects, especially when resolving small details in moving body features.
Innovation Solution
A method and apparatus for acquiring imaging data at multiple energy states during a single scan by modulating the x-ray source between two voltage levels (e.g., 80 kVp and 140 kVp) at multiple-view intervals, minimizing patient motion and cone angle effects, allowing simultaneous data acquisition at both energy states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate scans are performed at different kVp levels, then dual energy imaging data can be acquired, but mis-registration occurs due to patient motion and cone angle effects
Solution Approach 1:
The patent combines multiple energy state data acquisition into a single scan by modulating the x-ray source voltage between different kVp levels (e.g., 80 kVp and 140 kVp) at multiple-view intervals. This merging of acquisitions into one temporal event eliminates patient motion and cone angle effects that cause mis-registration between separate scans, while maintaining the dual energy imaging capability.
Solution Approach 2:
The x-ray source voltage is modulated periodically between different kVp levels at multiple-view intervals during the scan. This periodic switching allows the system to acquire data at different energy states sequentially within a single rotation, enabling dual energy imaging without requiring separate scans, thus eliminating mis-registration while maintaining scan time efficiency.
2Measurement precision
If sequential scans are performed at different energy states, then material characterization can be achieved, but patient motion causes mis-registration
Solution Approach 1:
The patent merges sequential energy state acquisitions into a single scan by modulating the x-ray source voltage between different kVp levels at multiple-view intervals. This ensures that all material characterization data is acquired during the same temporal event, eliminating patient motion artifacts and ensuring image consistency while maintaining accurate material characterization.
3Measurement precision
If dual energy imaging is performed with separate scans, then energy discrimination is achieved, but cone angle effects introduce errors
Solution Approach 1:
The patent combines dual energy acquisitions into a single scan with voltage modulation at multiple-view intervals. This ensures that the cone angle geometry remains consistent for both energy states since they are acquired during the same spatial configuration, eliminating cone angle effects that would otherwise introduce errors in energy discrimination and imaging accuracy.
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 reduces mis-registration between dual energy image datasets, enabling enhanced contrast separation and accurate material characterization with minimal patient motion and cone angle effects, facilitating reliable imaging of moving body features.
Implementation Method 1
an x-ray source configured to project x-rays having multiple energies toward the subject, and a generator configured to energize the x-ray source to a first voltage and configured to energize the x-ray source to a second voltage
Implementation Method 2
a scintillator for converting x-rays to light energy adjacent the collimator
Implementation Method 3
photodiodes for receiving the light energy from the adjacent scintillator and producing electrical signals therefrom
Implementation Method 4
The intensity of the attenuated beam radiation received at the detector array is typically dependent upon the attenuation of the x-ray beam by the subject
Data Source
AI summary
A CT system includes a rotatable gantry having an opening for receiving a subject to be scanned, a rotatable gantry having an opening for receiving a subject to be scanned, an x-ray source configured to project x-rays having multiple energies toward the subject, and a generator configured to energize the x-ray source to a first voltage and configured to energize the x-ray source to a second voltage, the first voltage distinct from the second voltage. The system further includes a controller configured to cause the generator to energize the x-ray source to the first voltage for a first duration, acquire imaging data for at least one view during at least the first duration, after the first duration, cause the generator to energize the x-ray source to the second voltage for a second duration, and acquire imaging data for two or more views during at least the second duration.