Grated Collimator for CT Perfusion Dose Reduction
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Solution Overview
Problem
Conventional perfusion CT imaging is limited by high radiation doses and the lack of standardized protocols, which restricts its clinical application in fields like stroke assessment, oncology, and cardiac and kidney function due to concerns about radiation exposure.
Innovation Solution
The implementation of a transverse dynamic collimator, grated collimator, adaptive sampling algorithm, or adaptive exposure algorithm to reduce the x-ray dose during CT perfusion scans without compromising clinical accuracy, allowing for the use of perfusion CT in applications previously limited by radiation concerns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional perfusion CT imaging is used to scan large volumes quickly, then scanning speed and coverage are improved, but radiation dose increases significantly
Solution Approach 1:
The patent divides the radiation beam into multiple discrete fan beams, each directed at a specific angle toward the volume of interest. Instead of using a single broad beam that exposes the entire body, multiple narrow beams are segmented and directed precisely at the target region, reducing unnecessary radiation exposure to surrounding tissues while maintaining scanning speed.
Solution Approach 2:
The patent implements localized radiation delivery by directing individual fan beams only at the volume of interest rather than using a broad beam. Each beam is tailored to its specific angular position, ensuring that radiation is concentrated where needed (the target volume) and minimized elsewhere, thus reducing overall radiation dose while maintaining diagnostic quality.
2Area of stationary object
If a broad radiation beam is used to cover large volumes, then scanning coverage is improved, but radiation exposure to non-target areas increases
Solution Approach 1:
The patent segments the broad radiation beam into multiple narrow fan beams, each directed at a specific angular position. This segmentation allows the system to cover a large volume by combining multiple targeted beams rather than using a single broad beam, thereby reducing radiation exposure to non-target areas while maintaining comprehensive scan coverage.
Solution Approach 2:
The patent introduces angular positioning as an additional dimension for beam direction. By controlling beams from multiple angular positions around the patient, the system achieves three-dimensional volume coverage through the combination of angular variation and axial translation, replacing the need for a single broad beam with multiple precisely directed narrow beams.
3Object-affected harmful factors
If multiple fan beams are directed at the volume of interest, then radiation dose is reduced, but system complexity increases
Solution Approach 1:
The patent employs a dynamic collimator system that can translate and rotate to position multiple fan beams at different angular positions and axial locations. This dynamic capability allows the system to adaptively configure the beam geometry for each scan, enabling precise radiation delivery while managing complexity through automated control rather than fixed mechanical structures.
Solution Approach 2:
The patent designs the collimator system to perform multiple functions: it can translate axially, rotate angularly, and direct multiple fan beams simultaneously. This multi-functionality allows a single collimator assembly to handle various scan configurations and patient anatomies, reducing the need for multiple specialized components and managing overall system complexity.
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
Significantly reduces the radiation dose delivered to patients, enabling the broader application of perfusion CT in diagnostic and therapeutic contexts while maintaining diagnostic accuracy, as demonstrated by reduced skin exposure in heart and kidney scans.
Implementation Method 1
each of the first and second gratings comprising a plurality of attenuating members with a plurality of secondary radiation delivery windows extending between adjacent attenuating members
Data Source
AI summary
A collimator for a computed tomography imaging device can include first and second leaves positioned on opposing sides of a primary radiation delivery window. The first and second leaves can include first and second gratings having a plurality of attenuating members with a plurality of secondary radiation delivery windows extending between adjacent attenuating members.