Dynamic Pre-Object Filter for CT Radiation Attenuation
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Solution Overview
Problem
Conventional CT imaging systems use pre-object filters that are not tailored to individual patient sizes or anatomical regions, leading to inefficient radiation dosage and image quality, particularly for patients outside average sizes.
Innovation Solution
A pre-object filter system that adjusts its profile of radiation attenuation in the fan-angle direction based on the patient's profile, allowing for translation, rotation, or oscillation to match the patient's size and shape, ensuring optimal radiation dosage and image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional pre-object filters are used for average patient sizes, then radiation dosage is reduced for average patients, but image quality deteriorates for patients outside average sizes
Solution Approach 1:
The pre-object filter is made dynamically adjustable through translation along the patient axis and rotation about the fan-angle direction, allowing the filter profile to be adapted to match different patient sizes and anatomical regions. This dynamic adjustment enables optimal radiation attenuation for each patient, resolving the contradiction between radiation reduction and image quality maintenance.
Solution Approach 2:
The filter position parameters (translation distance and rotation angle) are changed based on patient profile measurements to optimize radiation attenuation. By adjusting these parameters according to patient size and anatomy, the system maintains image quality while reducing radiation dosage for non-average patients.
2Manufacturing precision
If pre-object filters are tailored for individual patient sizes, then image quality is improved for all patients, but device complexity increases
Solution Approach 1:
A single pre-object filter assembly performs multiple functions by combining translation and rotation capabilities, replacing the need for multiple fixed filters. This universal filter can be adjusted to match any patient size or anatomical region, reducing device complexity while maintaining image quality.
Solution Approach 2:
The system automatically determines patient profile and calculates optimal filter position and orientation, then adjusts the filter accordingly. This self-service approach minimizes manual intervention and complex operational procedures while achieving personalized image optimization.
3Object-affected harmful factors
If radiation dosage is reduced using fixed pre-object filters, then patient exposure is minimized, but signal-to-noise ratio deteriorates for non-average patients
Solution Approach 1:
The filter attenuation parameters are changed based on patient profile to optimize the balance between radiation dosage and signal-to-noise ratio. For non-average patients, the adjusted parameters ensure sufficient photons reach the detector while minimizing unnecessary radiation exposure, maintaining measurement precision.
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 reduces radiation dosage while maintaining desired imaging specifications, mitigates pulse pile-up, and improves signal-to-noise ratio, resulting in better image quality and low-contrast detectability.
Implementation Method 1
a pre-object filter configured to shape a profile of radiation attenuation in a fan-angle direction as a function of a profile of an object being examined
Data Source
AI summary
Among other things, one or more systems and/or techniques are described for shaping a profile of radiation attenuation in a fan-angle direction via a pre-object filter (e.g., a bowtie filter) based upon a profile of an object. For example, a pre-object filter may be at least partially rotated about a filter axis and/or may be translated in a direction parallel to a direction of conveyance of the object under examination to adjust a profile of radiation attenuation in the fan-angle direction. Further, in one embodiment, the profile of radiation attenuation may be reshaped during rotation of the radiation source about the object to adjust an amount of radiation attenuation in the fan-angle direction (e.g., to adjust a profile of radiation attenuation as a shape of the object changes from a perspective of a radiation source as the radiation source is rotated about the object).