Radiography Cross-Scatter Correction via Patient Modeling
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Solution Overview
Problem
Existing radiography methods struggle to produce high-quality images of overweight and obese patients due to excessive scattered x-rays, which lead to a high dose requirement and reduced signal-to-noise ratio.
Innovation Solution
A method of radiography that involves synchronous vertical scanning with two radiation sources and detectors, followed by a computed correction process to reduce cross-scattering between frontal and lateral raw images, using patient-specific modeling and radiation scattering representation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If scattering rejection grids and narrow collimation are used to reduce scattered x-rays, then scattered radiation rejection is improved, but the received radiation signal level on detectors deteriorates
Solution Approach 1:
The patent replaces mechanical scattering rejection grids and narrow collimation with a computational approach. A measured scatter kernel is convolved with an estimate of the scatter source distribution to calculate scatter rejection, eliminating the need for physical grids and narrow collimation while maintaining scatter rejection performance and preserving signal level.
Solution Approach 2:
The patent changes the approach from physical parameter optimization (grid design, collimation aperture size) to computational parameter optimization (scatter kernel convolution, scatter source distribution estimation). This allows scatter rejection without the signal loss inherent in mechanical approaches.
2Object-affected harmful factors
If very thin object and detector collimations are used to achieve efficient scattered x-ray rejection, then scattered radiation rejection is improved, but the useful dose rate fraction deteriorates
Solution Approach 1:
The patent replaces mechanical collimation systems with a computational scatter rejection method. By convolving a measured scatter kernel with the scatter source distribution, the system achieves scatter rejection without the dose rate fraction loss caused by narrow mechanical collimation apertures.
Solution Approach 2:
The patent introduces a computational intermediary (scatter kernel convolution process) between the x-ray source and detector. This computational mediator calculates and removes scatter contributions without physically blocking x-rays, thereby preserving the useful dose rate fraction while achieving scatter rejection.
3Object-affected harmful factors
If narrow collimation is used to achieve high scattering rejection rate, then scattered radiation rejection is improved, but the received radiation signal on detectors deteriorates
Solution Approach 1:
The patent substitutes mechanical narrow collimation with a computational scatter rejection algorithm. The measured scatter kernel is convolved with the scatter source distribution to calculate and remove scatter, achieving high scattering rejection rate without the signal attenuation caused by narrow physical collimation.
Solution Approach 2:
The patent creates a computational copy of the scatter distribution through kernel convolution and subtracts it from the measured signal. This allows scatter rejection without physically restricting the x-ray beam, thereby maintaining the received radiation signal level while achieving high scattering rejection rate.
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 the capability to produce clinical quality images with improved spatial resolution, signal-to-noise ratio, and contrast, while reducing the impact of cross-scattered and self-scattered radiation.
Implementation Method 1
x-ray emission source emitting x-ray spectra having a higher energy comprised between 20keV and 200keV
Implementation Method 2
the direct x-ray beam much attenuated
Implementation Method 3
the big amount of scattered x-rays created while the direct x-ray beam much attenuated
Data Source
Figure 1
Figure 2A~2D
Figure 3A
AI summary
This invention relates to a method of radiography of an organ of a patient, comprising: first vertical scanning and said second vertical scanning being performed synchronously, wherein a computed correction is processed on both first and second raw images, on at least part of patient scanned height, for at least overweight or obese patients, so as to reduce, between first and second corrected images, cross-scattering existing between said first and second raw images, and wherein said computed correction processing on both said first and second raw images comprises: a step (32, 33, 34) of making a patient specific modeling, using as patient specific data therefore at least both first and second raw images, preferably mainly both first and second raw images, more preferably only both first and second raw images, a step (34, 35) of determining a patient specific representation of radiation scattering by said patient specific modeling, a step (36) of processing said patient specific radiation scattering representation on both said first and second raw images so as to get said first and second corrected images.