X-ray CT Scanner Pre-scan Timing Control
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Solution Overview
Problem
Conventional X-ray CT apparatuses face challenges in accurately determining the timing to start a main scan due to movement-related issues, such as heartbeat, breathing, or body movements, which can cause high CT value regions to enter or exit the region of interest (ROI) set in non-contrast images, leading to incorrect timing for starting the scan.
Innovation Solution
The X-ray CT apparatus includes a pre-scan control unit, image generating unit, region setting unit, and timing sensing unit to perform a pre-scan, set a larger region encompassing the ROI, and determine if high pixel values exist within this region, thereby accurately sensing the timing to start the main scan when the ROI's pixel value exceeds a threshold after contrast medium injection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If Real Prep is used to sense timing for main scan, then scan automation is improved, but measurement precision deteriorates due to body movement causing high CT value regions to enter or exit ROI
Solution Approach 1:
The system performs preliminary actions by setting a larger region around the ROI before the main scan to predict and account for potential movements of high CT value regions. This preliminary region definition allows the system to anticipate movement-related errors and adjust timing detection accordingly, resolving the contradiction between automation and precision.
2Ease of operation
If ROI is set on non-contrast image, then operation simplicity is improved, but reliability deteriorates due to inability to account for moving high CT value regions
Solution Approach 1:
The system extends the detection space by defining a larger region that encompasses the original ROI plus surrounding areas. This dimensional expansion allows the system to monitor for high CT value regions that may move into the original ROI during scanning, thereby maintaining operational simplicity while improving reliability through broader spatial monitoring.
3Measurement precision
If larger region is used for determining high pixel values, then timing accuracy is improved, but device complexity increases
Solution Approach 1:
The system segments the monitoring task by dividing the larger region into the original ROI and surrounding prediction zones. This segmentation allows the processing to focus on specific sub-regions with different purposes: the original ROI for primary measurement and the surrounding areas for movement prediction, thereby improving timing accuracy while managing processing complexity through structured division.
Data Source
AI summary
An X-ray CT apparatus has a scanner, a pre-scan control unit, an image generating unit, a region setting unit and a timing sensing unit. The pre-scan control unit controls an operation of the scanner to perform a pre-scan. The image generating unit generates image data of the object based upon the pre-scan. The region setting unit sets, on the basis of the image data, a region of interest, and a larger region encompassing the region of interest and a region around the region of interest and being used to determine whether or not a high pixel value region exists. The timing sensing unit senses, if the larger region does not include a pixel value higher than a first threshold, a timing to start a main scan, at which a pixel value of the region of interest exceeds a second threshold after injection of the contrast medium agent is started.