Motor-Driven Perfusion Phantom for CT Calibration
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Solution Overview
Problem
Static phantoms are inadequate for quality assurance and calibration of CT devices in capturing dynamically changing images, particularly in perfusion analysis where contrast agent progression is essential.
Innovation Solution
A perfusion phantom with modular design and motor-driven carriage system that moves sample rods through the CT device, simulating blood perfusion by varying CT numbers, allowing for accurate calibration and quality assurance of CT number time-density curves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If static phantoms are used for CT device quality assurance, then device calibration can be performed, but the phantom cannot simulate dynamically changing perfusion conditions
Solution Approach 1:
The patent transforms the static phantom into a dynamic system by introducing a motor-driven carriage that moves sample rods through the CT scan field. The carriage system includes a motor, drive mechanism, and positioning system that enables controlled movement of phantom components to simulate blood flow dynamics and contrast agent progression through vascular and tissue regions
Solution Approach 2:
The phantom is divided into multiple sample rods representing different tissue types and vascular structures. Each sample rod contains materials with specific CT numbers that simulate different perfusion characteristics. This segmentation allows independent movement and positioning of each rod to create complex perfusion patterns
2Adaptability or versatility
If a motor-driven carriage system is added to simulate dynamic perfusion, then perfusion pattern simulation capability is improved, but device complexity increases
Solution Approach 1:
The motor-driven carriage system serves multiple functions: it positions sample rods for different perfusion simulations, controls movement speed to match physiological flow rates, and can be programmed with different motion profiles for various tissue types. This multi-functionality reduces the need for separate phantoms for different perfusion scenarios
Solution Approach 2:
The system controls perfusion simulation by varying parameters such as carriage speed, acceleration, and position to match physiological blood flow characteristics. Different sample rods can be moved at different speeds and patterns to simulate arterial, venous, and capillary perfusion, as well as normal and abnormal perfusion conditions
3Measurement precision
If multiple sample rods representing different tissue types are used, then measurement precision of CT number time-density curves is improved, but manufacturing complexity increases
Solution Approach 1:
Each sample rod is constructed with specific materials and densities to represent different tissue types with characteristic CT numbers. The phantom includes rods with varying compositions (e.g., water-equivalent, soft tissue-equivalent, bone-equivalent materials) to simulate the unique attenuation properties of different anatomical structures during perfusion
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
Enables accurate calibration and quality assurance of CT devices in perfusion analysis by simulating normal and abnormal perfusion patterns, facilitating diagnostic insights and minimizing radiation exposure.
Implementation Method 1
motor-driven carriage system that moves sample rods through the CT device
Implementation Method 2
Computed tomography (CT) device... track the progression of the contrast agent through the region of interest (ROI)... determine a CT number of each of the ROIs in the successive CT images
Data Source
AI summary
A computed tomography perfusion phantom includes a scanned plane configured to align with an imaging plane of a CT device. A sample rod extends through the scan plane and includes a plurality of adjacent cells. The plurality of adjacent cells are each constructed of materials having predetermined CT numbers and the plurality of adjacent cells include cell of a plurality of CT numbers. A drive motor is coupled to the sample rod and the drive motor moves the sample rod through the scan plane. A method of calibrating a CT device with the perfusion phantom includes aligning the scan plane of the perfusion phantom with an imaging plane of the CT device. The drive motor moves the sample rod through the scan plane of the perfusion phantom. A plurality of CT number measurements of the sample rod are acquired through the scanned plane of the perfusion phantom.