Axially Segmenting PET Data for Uniform Sensitivity
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Solution Overview
Problem
PET systems using the step-and-shoot method face non-uniform sensitivity issues, leading to inconsistent image quality due to uneven signal-to-noise ratios, which complicates image reconstruction across overlapping frames.
Innovation Solution
The method involves defining a scan window with two data bins and a transition region within a PET imaging system, where emission data is binned and reconstructed continuously during a continuous table motion scan, allowing for concurrent data storage and image reconstruction, thereby reducing reconstruction time and improving image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If step-and-shoot method is used to acquire emission data, then the PET system can acquire data at discrete axial positions, but the sensitivity profile becomes non-uniform resulting in inconsistent image quality
Solution Approach 1:
The patent divides the continuous scan window into multiple discrete axial segments (first axial segment, second axial segment, etc.), each with its own data bin. This segmentation allows the system to process data from different axial positions independently while maintaining uniform sensitivity across all segments, thereby resolving the image quality consistency issue.
Solution Approach 2:
The patent applies different processing characteristics to different axial segments by creating separate data bins for each segment. Each segment can be processed with appropriate local parameters while contributing to the overall uniform sensitivity profile, ensuring consistent image quality across the entire field of view.
2Area of stationary object
If emission data is acquired at different individual axial positions using step-and-shoot, then the PET system can cover the entire scan range, but a weighted average must be used for reconstruction at overlapping areas increasing processing complexity
Solution Approach 1:
The patent segments the scan window into discrete axial segments with defined overlaps, creating separate data bins for each segment. This segmentation allows simple additive combination of data bins during reconstruction, eliminating the need for complex weighted average calculations while maintaining full scan coverage.
Solution Approach 2:
The patent merges data from overlapping axial segments by combining their respective data bins directly. This simple merging approach replaces complex weighted averaging, reducing processing complexity while maintaining comprehensive scan coverage through the overlapping segment design.
3Productivity
If step-and-shoot mode is used, then the PET system acquires emission data sequentially, but image reconstruction must be performed frame by frame increasing reconstruction time
Solution Approach 1:
The patent performs preliminary organization of data into separate bins during the acquisition phase, preparing the data structure in advance. This preliminary binning enables parallel processing during reconstruction, allowing multiple frames to be reconstructed simultaneously rather than sequentially, thereby reducing total reconstruction time.
Solution Approach 2:
The patent creates a dynamic data organization system where data is continuously binned into appropriate axial segments during acquisition. This dynamic binning approach enables flexible parallel reconstruction of multiple frames simultaneously, transforming the sequential reconstruction process into a parallel one that significantly reduces reconstruction time.
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 image reconstruction efficiency by maintaining full sensitivity across data bins, enabling image reconstruction before the completion of the scan and allowing for gated acquisition only where needed, thus improving image quality and reducing noise.
Implementation Method 1
When a positron interacts with an electron by annihilation, the entire mass of the positron-electron pair is converted into two 511 keV photons
Implementation Method 2
The photons are emitted in opposite directions along a line of response. The annihilation photons are detected by detectors that are placed along the line of response on a detector ring
Data Source
AI summary
A method for generating a Positron Emission Tomography (PET) image includes defining a scan window having a predetermined length along an examination axis of a PET imaging system, the scan window corresponding to a region of interest to be continuously scanned by the PET imaging system, defining at least two data bins corresponding to two separate scan regions within the scan window, defining a transition region that overlaps a portion of each of the separate scan regions within the scan window, the transition region having a width that is shorter than a length of the scan window, binning emission data acquired within the transition region into the two data bins, binning emission data acquired from outside the transition region into one of the two data bins, and reconstructing an image using the emission data in the two data bins.