Bowtie Filter Attenuation Map Visualization for CT Centering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In computed tomography (CT) imaging, the use of a bowtie filter to adjust x-ray beam attenuation is hindered when the anatomy of interest is not centered relative to the filter, leading to reduced image quality due to unnecessary beam attenuation.
Innovation Solution
A method is implemented to display a representation of the attenuation map of the bowtie filter overlaid on an image of the anatomy, prompting the operator to reposition the subject or change the filter to ensure the anatomy is aligned with the center of the bowtie filter, thereby minimizing unnecessary beam attenuation and improving image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a bowtie filter is used to adjust x-ray beam attenuation, then radiation dose on the periphery is reduced and signal amplitude is improved, but image quality deteriorates when anatomy is not centered relative to the filter
Solution Approach 1:
The system performs a scout scan before the main diagnostic scan to obtain preliminary anatomical information. Based on this preliminary data, the system automatically selects and positions the appropriate bowtie filter configuration, ensuring the anatomy is properly centered before the actual imaging occurs, thus preventing image quality degradation
Solution Approach 2:
The system uses the scout scan images as feedback to automatically adjust the bowtie filter positioning and selection. The feedback loop ensures that the filter is optimally positioned relative to the patient's anatomy before the diagnostic scan, resolving the contradiction between radiation protection and image quality
2Loss of time
If the anatomy is not centered relative to the bowtie filter, then setup time is reduced, but unnecessary beam attenuation occurs leading to reduced image quality
Solution Approach 1:
The system performs automatic bowtie filter positioning based on scout scan data without requiring manual operator intervention. The system automatically calculates the optimal filter position and configures it, enabling the system to serve itself in the positioning task, thus reducing setup time while maintaining image quality
Solution Approach 2:
The scout scan is performed in advance to gather anatomical information needed for automatic filter positioning. This preliminary action enables the system to pre-position the bowtie filter correctly before the diagnostic scan, eliminating the need for time-consuming manual adjustments while ensuring proper alignment
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 quality by ensuring that only non-attenuated beams are directed at the anatomy of interest, maintaining a uniform flux and reducing radiation exposure, thus improving the scan field of view and overall imaging performance.
Implementation Method 1
The x-ray beam passing through a portion of the bowtie filter may be attenuated with the attenuation increasing gradually towards the edge of the filter
Data Source
AI summary
Various methods and systems are provided for displaying to an operator an attenuation map of a filter relative to a current location of an anatomical feature of a subject; and in response to the anatomical feature being within a region of the attenuation map, prompting an operator to reposition the subject. In this way, centering of the anatomical feature relative to an attenuation system may be facilitated for improved image quality.