Adaptive SPECT Pixel Adjustment to Reduce Penetrating Photon Artifacts
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Solution Overview
Problem
High-energy photons penetrating the shielding of SPECT detectors cause artifacts and reduce image quality, leading to reduced visibility of internal structures and misinterpretation by reconstruction algorithms.
Innovation Solution
Adaptive pixel zeroing method where a reconstruction algorithm is selectively applied to a first portion of pixels in projection views, ignoring a second portion including artifacts, with the number of ignored pixels varying based on detector sweep angles to mitigate the effects of penetrating photons.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If shielding is added around detector sides to prevent photons from outside the specified angle range, then detection accuracy is improved, but high-energy photons can penetrate the shielding and cause artifacts
Solution Approach 1:
The patent converts the harmful penetrating photons into a detectable signal by using the same detector to measure both collimated and non-collimated photons. The system then uses image processing algorithms to identify and remove artifacts caused by penetrating photons, effectively converting the harmful penetration effect into useful information that can be corrected.
Solution Approach 2:
The patent segments the detected photons into two categories: collimated photons (from the specified angle range) and non-collimated photons (penetrating photons from outside the angle range). By separating these two types of photons through angular discrimination and image processing, the system can selectively use the valid collimated photons for accurate imaging while identifying and removing artifacts from penetrating photons.
2Loss of information
If all pixels in projection views are used for image reconstruction, then image data completeness is improved, but artifacts from penetrating photons reduce image quality
Solution Approach 1:
The patent applies local quality by treating different regions of the projection views differently. Specifically, it identifies regions containing artifacts from penetrating photons and applies different processing weights to these regions versus regions with valid collimated photon data. This allows the system to maintain high image quality by giving less weight to artifact-prone regions while preserving useful information from valid regions.
Solution Approach 2:
The patent uses partial action by selectively excluding certain pixels or regions from image reconstruction when those regions contain significant artifacts from penetrating photons. Rather than using all available pixel data uniformly, the system applies a weighting scheme or masking approach that partially excludes problematic data, thereby improving overall image quality at the cost of using slightly less information.
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 method effectively reduces artifacts in reconstructed SPECT images, enhancing image quality and visibility of internal structures, allowing for more accurate diagnosis and treatment planning.
Implementation Method 1
The radioactive substance emits photons, which are collimated and detected by a detector subsystem. Detectors of the subsystem may generate output electrical signals
Data Source
AI summary
Methods and systems are provided for increasing a quality of images generated by a single photon emission computed tomography (SPECT) imaging system. Photons penetrating a protective shielding around detector heads of the SPECT system may not be handled correctly by a reconstruction algorithm used to reconstruct an image from a plurality of projection views acquired by the SPECT imaging system, generating artifacts and reducing a quality of the image. In one embodiment, the artifacts may be reduced or eliminated by selectively applying the reconstruction algorithm to a first portion of pixel columns of the projection views not including the artifacts, and not applying the reconstruction algorithm to a second portion of pixel columns of the projection views including the artifacts. A number of the second portion of pixel columns may be based on a sweep angle of a detector acquiring a projection view.