Tomographic Imaging Detector Fractional Shift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional tomographic imaging systems face limitations in achieving high resolution due to detector size constraints and non-uniform sampling, leading to increased costs and complexity, especially in cone-beam and spiral scans.
Innovation Solution
The method involves shifting detectors or radiation sources by fractional values at each angular position during data acquisition, using iterative reconstruction techniques and Archimedean spiral sampling patterns to enhance resolution and accuracy, allowing for ultra-high resolution imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If detector size is reduced to improve resolution, then image resolution is improved, but device complexity and cost increase
Solution Approach 1:
The patent applies dynamics by making the detector system movable rather than fixed. The detector is shifted by a fractional value at each angular position during data acquisition, creating a dynamic sampling pattern that effectively reduces the required detector element size while maintaining resolution. This dynamic shifting approach allows larger detector elements to achieve the same resolution as smaller fixed detectors would provide.
Solution Approach 2:
The patent changes the sampling parameter by introducing a fractional shift value that varies with angular position. This parameter change transforms the sampling pattern from a regular grid to a non-uniform pattern, effectively increasing the sampling density and resolution without requiring physically smaller detector elements or more complex detector arrays.
2Measurement precision
If detector size is reduced to improve resolution, then image resolution is improved, but system cost increases
Solution Approach 1:
By implementing dynamic shifting of the detector during acquisition, the system achieves high resolution using larger, less expensive detector elements. The fractional shift approach allows the system to effectively sample at a finer resolution than the physical detector pitch would suggest, avoiding the need for costly small-pitch detector arrays.
Solution Approach 2:
The patent modifies the acquisition parameter by introducing angular-position-dependent fractional shifts. This parameter change enables the system to achieve ultra-high resolution through software-controlled sampling patterns rather than hardware-intensive detector configurations, significantly reducing system cost.
3Ease of operation
If regular polar coordinate grid sampling is used, then data acquisition is simple, but sampling density is insufficient for high resolution
Solution Approach 1:
The patent transforms the sampling pattern by applying a fractional shift parameter that varies with angular position. This changes the sampling from a regular polar grid to a non-uniform pattern that provides denser sampling in critical regions. The shift value is defined as a fraction of the detector size and varies according to the angular position, creating an optimized sampling density without complicating the acquisition process.
Solution Approach 2:
The sampling pattern becomes dynamic rather than static. The detector position is adjusted dynamically based on angular position, creating a time-varying sampling pattern that achieves higher effective sampling density. This dynamic approach maintains ease of operation while dramatically improving sampling density and resolution.
4Quantity of substance
If quarter-detector offset approach is used, then additional views are provided, but sampling in detector row direction is not improved
Solution Approach 1:
The patent applies fractional shifts in the detector row direction that vary with angular position. This parameter change creates non-uniform sampling density that specifically addresses the undersampling in the detector row direction. The shift value is calculated as a fraction of detector size and applied dynamically, providing improved sampling density where needed while maintaining the benefits of the quarter-detector offset approach.
Data Source
AI summary
A system and method for producing an image of a subject with a tomographic imaging system are provided. A tomographic imaging system is operated to rotate a radiation detector, radiation source, or both through a plurality of angular positions around a subject while acquiring data. As the radiation detector or source is rotated, the radiation detector or source is shifted at each angular position by a different shift value. An image of the subject is reconstructed from the acquired data using a reconstruction technique that incorporates the shifts applied to the detector, source, or both into a system matrix.