Dynamic Collimator for CT Perfusion Dose Reduction
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Solution Overview
Problem
Conventional perfusion CT imaging is limited by high radiation doses and lack of standardized protocols, restricting 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
1Productivity
If conventional perfusion CT imaging is used to scan large volumes with multiple-slice detectors, then the ability to quickly scan whole or large portions of organs is improved, but the radiation dose delivered to the subject increases significantly
Solution Approach 1:
The patent implements dynamic collimation where the collimator aperture is continuously adjusted during the scan based on the position of the radiation beam. The aperture is opened wider when the beam is over regions of interest requiring perfusion imaging, and closed narrower when the beam is over non-critical regions, thereby dynamically optimizing the balance between diagnostic quality and radiation dose
Solution Approach 2:
The system applies different collimation settings to different spatial regions during the scan. Regions of interest (such as kidneys, pancreas, liver) receive full beam exposure for high-quality perfusion imaging, while non-critical regions receive reduced exposure through narrowed collimation, creating locally optimized radiation delivery
2Object-affected harmful factors
If the radiation dose is reduced to make perfusion CT clinically viable, then the safety and adaptability of the procedure is improved, but the image quality and diagnostic accuracy may deteriorate
Solution Approach 1:
The system performs a preliminary identification of regions of interest before the actual perfusion scan. Based on this preliminary information, the collimation strategy is pre-planned and optimized for each specific patient and organ, ensuring that radiation is concentrated on areas requiring diagnostic evaluation while minimizing exposure elsewhere
Solution Approach 2:
The system uses real-time feedback from the scanning process to adjust collimation dynamically. The control system monitors beam position and organ location, continuously optimizing the collimator aperture to maintain diagnostic quality in critical regions while reducing dose in non-critical regions throughout the scan
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 radiation dose during CT perfusion scans, enabling its broader application in diagnostic and therapeutic contexts while maintaining diagnostic accuracy, particularly in cardiac and kidney imaging.
Implementation Method 1
attenuating, between the primary and secondary windows, at least a third portion of the radiation
Data Source
AI summary
A method of contrast-enhanced computed tomography (CT) imaging can include repeatedly scanning a target region an applied power during a session. The applied power can be a first power for a first scan. After the first scan, the applied power for each of a plurality of scans can be selected based on an algorithm. The algorithm can be based on, for example, the attenuation indicated from a preceding scan in the session.