X-ray CT Control Unit Synchronizing Scan Speed with Contrast Agent Arrival
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Solution Overview
Problem
In X-ray CT apparatuses using multiple-channel or cone beam X-ray detectors, the increased helical pitch and detector width lead to faster scan speeds, potentially outpacing the movement of contrast agents in blood flow, resulting in inadequate contrast imaging.
Innovation Solution
An X-ray CT apparatus with a control unit that performs monitoring scans at multiple positions along the body axis to detect the arrival of a contrast agent, prioritizing image reconstruction at positions where the agent has arrived, and continuing the main scan only when the agent is present, ensuring proper contrast imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the helical pitch and detector width are increased to improve scanning speed and coverage, then the scan speed increases, but the scan speed becomes faster than the contrast agent movement speed, resulting in inadequate contrast imaging
Solution Approach 1:
The patent dynamically adjusts the scan progress speed based on real-time detection of contrast agent arrival. The control unit monitors contrast agent position and varies the helical scan speed accordingly - slowing down when the contrast agent is approaching the imaging region and speeding up when it has passed, thereby maintaining optimal imaging conditions throughout the scan
Solution Approach 2:
The system implements a feedback mechanism where the control unit continuously detects the contrast agent's arrival position during the helical scan and uses this information to adjust the scan speed in real-time. This closed-loop control ensures the scan speed remains synchronized with the contrast agent movement, resolving the contradiction between high scan speed and imaging quality
2Measurement precision
If a monitoring scan is performed to detect contrast agent arrival, then contrast agent arrival can be detected, but the scan time increases
Solution Approach 1:
Instead of performing continuous monitoring scans throughout the entire imaging range, the patent performs monitoring scans only at specific predetermined positions where contrast agent arrival is expected. This partial monitoring approach provides sufficient detection accuracy while significantly reducing the time penalty compared to continuous monitoring
Solution Approach 2:
The system performs preliminary monitoring scans at predetermined positions before the main imaging scan to detect contrast agent arrival in advance. This allows the main scan to be optimized and accelerated once the contrast agent position is known, reducing overall scan time while maintaining detection accuracy
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 effective contrast imaging by synchronizing scan speeds with contrast agent movement, ensuring accurate image reconstruction and improved diagnostic quality.
Implementation Method 1
an imaging unit for reconstructing an image on the basis of projection data obtained by scanning a subject in which a contrast agent is injected with an X ray
Implementation Method 2
The control unit monitors arrival of the contrast agent by detecting the contrast agent by using an image obtained by reconstructing a slice image in the monitoring position. The contrast agent is detected on the basis of a CT number in the region of interest.
Data Source
AI summary
The present invention is directed to realize an X-ray CT apparatus for properly performing contrast imaging. An X-ray CT apparatus includes an imaging unit and a control unit for controlling the imaging unit. The control unit includes: a first control unit for performing a monitoring scan to monitor arrival of a contrast agent at a region of interest in a start position of a main scan in an imaging range of the main scan that is set along the body axis of the subject or a first monitoring position that is set before the start position in a scan progress direction and, on arrival of the contrast agent, starting the main scan; and a second control unit for monitoring whether or not the contrast agent has reached a region of interest in a second monitoring position provided on the forward side of the start position of the main scan in the imaging range in the scan progress direction on arrival of the main scan at the second monitoring position, when the contrast agent has reached the second monitoring position, continuing the main scan and, when the contrast agent has not reached the second monitoring position yet, performing a monitoring scan for monitoring arrival of the contrast agent.