Multiple X-ray Tube System for Cone Beam Artifact Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional CT scanners face issues with cone beam artifacts due to increased cone angles at the outer edges of the detector, leading to incomplete data sets and unstable image reconstruction, particularly in the cardiac region, and the complexity of aligning multiple x-ray tubes increases manufacturing costs.
Innovation Solution
A multiple x-ray tube system where two x-ray tubes are offset from the central axis in both the z-direction and circumferential direction, emitting overlapping fan-shaped x-ray beams to reduce cone beam artifacts and simplify the manufacturing process by ensuring complete data sets across the detector array.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the detector length is extended in the z-direction to cover the entire cardiac region, then the coverage is improved, but the cone angle increases leading to incomplete data sets and unstable reconstruction
Solution Approach 1:
The detector array is divided into multiple sub-arrays along the z-direction, each sub-array being imaged by a separate x-ray tube. This segmentation allows each detector sub-array to have a smaller effective cone angle while collectively covering the entire cardiac region, thus maintaining data completeness and reconstruction stability while achieving extended coverage.
2Manufacturing precision
If multiple x-ray tubes are spaced apart along the z-direction to decrease cone beam angles, then the cone beam artifacts are reduced, but the alignment and calibration complexity increases significantly
Solution Approach 1:
Multiple x-ray tubes are merged into a single rotating gantry assembly, where all tubes rotate synchronously around the patient. This combining approach maintains the benefits of multiple tubes (reduced cone angles) while simplifying alignment and calibration, as all tubes share a common rotational axis and can be calibrated relative to each other during the rotation process rather than requiring precise static alignment.
3Device complexity
If a single x-ray tube is used with a long detector, then the manufacturing complexity is reduced, but cone beam artifacts increase at the outer edges of the detector
Solution Approach 1:
The long detector is segmented into multiple shorter detector sub-arrays, each imaged by a dedicated x-ray tube. This segmentation reduces the effective cone angle for each detector sub-array, thereby minimizing cone beam artifacts at the edges while maintaining the ability to cover the entire cardiac region through the combined output of multiple tubes.
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 configuration reduces cone beam artifacts by ensuring complete data acquisition across the detector array, improving image stability and resolution, while simplifying the manufacturing process and reducing costs by eliminating the need for complex alignment of multiple x-ray tubes.
Implementation Method 1
The x-ray tube typically emits radiation, such as x-rays, toward the object
Implementation Method 2
Energy sensitive detectors may be used such that each x-ray photon reaching the detector is recorded with its photon energy
Data Source
AI summary
An imaging system includes a rotatable gantry having an opening therein to receive a subject to be scanned and configured to rotate about a central axis in a rotation direction. The imaging system also includes a first x-ray source coupled to the rotatable gantry at a first position, wherein the first position is offset from the central axis of the rotatable gantry by a first distance. Further, the imaging system includes a second x-ray source coupled to the rotatable gantry at a second position, wherein the second position is offset from the central axis of the rotatable gantry by a second distance, wherein the second position is offset from the first position in a direction coincident with the rotation direction, and wherein the second position is offset from the first position in a direction parallel to the central axis.