Adaptive Helical CT Scanner Cone Angle Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Helical computed tomography systems face challenges in achieving high temporal and spatial resolution while covering large volumes, often resulting in motion artifacts due to limited detector row usage and variable translation velocities, which can be inefficient and uncomfortable for subjects, especially in trauma cases.
Innovation Solution
A multi-slice computed tomography system with a processor-controlled device that adjusts the X-ray cone angle and tube current based on the position of the organ of interest within the examination volume, allowing for continuous transition and constant table feed, enabling high-resolution scans of organs like the heart within a single heartbeat without operator intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the number of detector rows is increased to cover large volumes, then the coverage is improved, but the temporal resolution deteriorates due to motion artifacts
Solution Approach 1:
The patent divides the detector array into multiple groups that can be independently controlled and illuminated. By selectively activating only the detector rows needed for the current scan region, the system achieves large volume coverage when needed while maintaining high temporal resolution by using fewer rows for focused organ scanning, thus resolving the contradiction between coverage and temporal resolution.
Solution Approach 2:
The system dynamically adjusts the number of illuminated detector rows based on the scanning requirements. The collimation is varied in real-time to match the organ region being scanned, allowing the system to transition between large-volume scanning and high-resolution organ imaging, thereby resolving the temporal resolution degradation that occurs with fixed large-row configurations.
2Productivity
If the translation velocity is increased for faster scanning, then the productivity is improved, but the motion artifacts increase reducing the image quality
Solution Approach 1:
The patent applies partial action by illuminating only the necessary portion of the detector rows corresponding to the organ region of interest. This reduces the total data acquisition burden and allows for faster scanning speeds without sacrificing image quality in the region of interest, as fewer detector elements need to be processed and synchronized with table motion.
Solution Approach 2:
The system provides different scanning qualities for different regions: high-resolution scanning for the organ of interest and reduced-resolution or overview scanning for surrounding areas. This local differentiation allows the table to move at higher speeds while maintaining high image quality where needed, resolving the contradiction between scanning speed and image quality.
3Volume of moving object
If the X-ray cone angle is increased to cover larger areas, then the coverage is improved, but the radiation dose increases
Solution Approach 1:
The patent implements local quality by adjusting the X-ray cone angle and collimation to match the specific organ region being scanned. Instead of maintaining a wide cone angle for entire large-volume coverage, the system narrows the cone angle to illuminate only the necessary detector rows for the current organ region, thereby reducing overall radiation exposure while maintaining adequate coverage for the region of interest.
Solution Approach 2:
The system uses partial action by activating only the portion of the X-ray beam and detector array needed for the current scan segment. This reduces the total radiation dose delivered to the patient while still achieving the necessary coverage for the organ being imaged, resolving the contradiction between coverage and radiation dose.
4Adaptability or versatility
If manual operator intervention is required for scan parameter adjustment, then the adaptability is improved, but the ease of operation deteriorates and time is lost
Solution Approach 1:
The patent implements self-service by providing automated detection and identification of organ regions from scout images. The system automatically determines the appropriate detector rows to illuminate and configures the scan parameters based on the detected organ position and size, eliminating the need for manual operator intervention while maintaining adaptability to different organs and scan requirements.
Solution Approach 2:
The system uses feedback from the scout image analysis to automatically adjust scan parameters. By detecting the organ region in the preliminary scout scan and using that information to configure the subsequent high-resolution scan, the system achieves adaptive optimization without requiring manual operator input, resolving the contradiction between adaptability and ease of operation.
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 allows for efficient, fast, and comfortable scanning of large volumes with reduced motion artifacts, enabling high temporal and spatial resolution images of organs of interest within a single operation, improving trauma response and operational efficiency.
Implementation Method 1
increasing an X-ray cone angle of the computed tomography system when the translation of the subject by the automated examination couch causes an organ region, which is defined on the computed tomography localizer radiograph and substantially delimits an organ of interest in the subject, to enter into the examination volume
Implementation Method 2
decreasing the X-ray cone angle when the translation of the subject causes the organ region to leave the examination volume
Implementation Method 3
acquired projection data for tomographic reconstruction
Data Source
AI summary
A device (10) for controlling an image acquisition of a multi-slice computed tomography system (1), MSCT, is disclosed. The device comprises an input (11) for receiving projection image data from the MSCT (1), an output (12) for controlling operation of the MSCT (1) and a processor (13). The processor (13) is adapted for controlling the MSCT to acquire a large volume localizer radiograph, and for defining an organ region in the localizer radiograph that delimits an organ of interest. The processor is adapted for acquiring a large volume helical CT scan of the subject, in which an X-ray cone angle is increased when the organ region in the subject is translated into the examination volume and decreased when the organ region is translated out of the examination volume.