ECG-Gated X-Ray Imaging for Myocardial Perfusion Quantification
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Solution Overview
Problem
Conventional X-ray diagnostic apparatuses face challenges in reducing radiation exposure and the amount of contrast medium required for both blood vessel morphology observation and myocardial perfusion imaging, which often necessitate prolonged radiography times, and lack the ability to quantitatively measure myocardial blood flow during coronary angiography.
Innovation Solution
The apparatus employs a pulse X-ray diagnostic system with ECG-gated mode and variable pulse rates to minimize radiation exposure, combined with image processing techniques to quantify myocardial perfusion, allowing for simultaneous observation of blood vessel morphology and myocardial perfusion with reduced contrast medium usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If radiography is performed for both blood vessel morphology observation and myocardial perfusion imaging, then comprehensive diagnostic information is obtained, but radiation exposure and contrast medium usage increase
Solution Approach 1:
The patent applies periodic pulsed X-ray irradiation synchronized with the cardiac cycle (ECG-gating), performing radiography at specific phases (diastole and systole) rather than continuous irradiation. This periodic action reduces total radiation exposure while capturing essential morphological and perfusion information at critical moments in the cardiac cycle
Solution Approach 2:
The patent dynamically adjusts the pulse rate and timing of X-ray irradiation based on the patient's heart rate and specific diagnostic needs. The system can switch between different pulse rates (e.g., 30fps for perfusion, lower for morphology) and adjust the radiography timing to optimize the balance between diagnostic quality and radiation dose
2Measurement precision
If radiography time is extended for myocardial perfusion imaging, then accurate perfusion measurement is achieved, but radiation exposure and contrast medium usage increase
Solution Approach 1:
The patent performs preliminary ECG-gated morphological imaging to establish baseline anatomical references and timing synchronization before perfusion imaging. This preliminary action allows the system to pre-calculate optimal radiography timing and pulse rates, enabling subsequent perfusion imaging to be more efficient and reduce contrast medium requirements
Solution Approach 2:
The patent uses real-time feedback from ECG signals and initial imaging data to dynamically adjust radiography timing and pulse rates during perfusion imaging. The system monitors contrast medium flow and adjusts the imaging protocol accordingly, reducing unnecessary exposures and optimizing contrast medium utilization
3Shape
If conventional X-ray angiography is used for blood vessel observation, then blood vessel morphology is visualized, but quantitative measurement of myocardial blood flow is not possible
Solution Approach 1:
The patent makes the X-ray angiography system multi-functional by integrating both morphological imaging and quantitative perfusion measurement capabilities into a single system. Through ECG-gating and dual-phase imaging (diastole for morphology, systole for perfusion), the system simultaneously achieves vessel visualization and blood flow quantification without requiring separate equipment
Solution Approach 2:
The patent changes key imaging parameters (pulse rate, timing, ECG synchronization) to transition between morphological imaging mode and perfusion measurement mode. By adjusting these parameters, the same hardware system can accurately capture both structural information and functional blood flow data
4Reliability
If separate radiographic cycles are performed for blood vessel morphology and myocardial perfusion, then each examination purpose is adequately addressed, but the amount of contrast medium injected doubles
Solution Approach 1:
The patent merges both morphological imaging and perfusion measurement into a single integrated radiographic cycle. By using ECG-gating to capture images at different cardiac phases within one contrast medium injection, the system combines the functionality of what would traditionally require two separate examinations, reducing contrast medium usage by approximately 50% while maintaining diagnostic quality
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 reduces radiation exposure and contrast medium usage while enabling accurate, quantitative measurement of myocardial blood flow, facilitating more efficient and effective coronary angiography procedures.
Implementation Method 1
an X-ray tube (20) and a high voltage generating unit (1)
Data Source
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AI summary
An image processing apparatus includes a storage unit (10) which stores the data of a plurality of images in an angiography sequence, and a computation unit (11) which generates a reference time density curve concerning a reference region set in a blood supply region to a blood supplied region and a plurality of time density curves concerning a plurality of local regions set in the blood supplied region on the basis of the data of a plurality of images, and computes a plurality of indexes respectively representing the correlations of the plurality of time density curves with respect to the reference time density curve.