FFR Estimation from CT Angiography Using Pixel-Wise Ratio Analysis

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Solution Overview

Problem

Current invasive coronary angiography (ICA) is costly and yields limited data, while non-invasive imaging technologies like Coronary Computed Tomography Angiography (CCTA) provide high sensitivity but may not offer real-time, accurate hemodynamic parameter estimation, particularly for fractional flow reserve (FFR) values.

Innovation Solution

A method using deep learning techniques and CT imaging to segment vasculature image data, determining a reference value based on the ascending aorta, and calculating FFR values on a pixel-by-pixel basis to generate an FFR image, which can be displayed quickly and accurately, applicable to various imaging modalities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If invasive coronary angiography (ICA) is used to obtain hemodynamic data, then data can be acquired through direct measurement, but the procedure becomes invasive and costly with limited data value

Engineering Contradiction:
Improvehemodynamic data accuracyVSAvoidinvasiveness and cost
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical/invasive measurement system (pressure catheter insertion) with a non-invasive imaging-based computational system. CT imaging captures vascular anatomy and contrast enhancement patterns, while computational algorithms estimate FFR values without physical intrusion into the vascular system, thereby eliminating procedural risks and costs associated with invasive catheterization.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces contrast media as an intermediary substance that enables non-invasive measurement. The contrast agent enhances vascular visibility in CT images and provides the necessary signal for computational FFR estimation, serving as a mediator between the imaging system and the hemodynamic parameters without requiring direct invasive measurement.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If non-invasive imaging technologies like CCTA are used, then patient morbidity is reduced, but real-time accurate hemodynamic parameter estimation is not provided

Engineering Contradiction:
Improvepatient morbidityVSAvoidhemodynamic parameter accuracy
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent segments the vascular system into distinct regions (reference vessel region and vessel region of interest) and processes image data at the pixel level. This segmentation enables precise localization of stenotic lesions and accurate calculation of FFR values for specific vascular segments while maintaining non-invasive imaging benefits.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transforms anatomical image parameters (pixel intensity values from CT scans) into functional hemodynamic parameters (FFR values). By establishing mathematical relationships between contrast enhancement patterns and blood flow dynamics, the system derives accurate hemodynamic information from non-invasive anatomical imaging data.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If traditional FFR measurement methods are used, then clinically-determined values are obtained, but the process is time-consuming and not suitable for real-time decision making

Engineering Contradiction:
Improveclinically-determined FFR valuesVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary processing of CT image data during the scanning process itself, extracting vascular geometry and contrast enhancement characteristics. This preliminary action prepares the data for rapid FFR calculation, enabling real-time or near-real-time hemodynamic assessment without requiring separate measurement procedures or prolonged processing times.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces time-consuming mechanical measurement procedures (invasive catheter-based pressure measurements) with rapid computational algorithms that process CT image data. This substitution dramatically reduces measurement time while maintaining clinical accuracy, enabling immediate diagnostic and treatment decisions.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS11744472B2Hemodynamic parameter estimation based on image data
Publication Date: 2023.09.05 GE PRECISION HEALTHCARE LLC
  • US11744472B2 patent drawing
  • US11744472B2 patent drawing
  • US11744472B2 patent drawing

AI summary

The present approach relates to determining a reference value based on image data that includes a non-occluded vascular region (such as the ascending aorta in a cardiovascular context). This reference value is compared on a pixel-by pixel basis with the CT values observed in the other vasculature regions. With this in mind, and in a cardiovascular context, the determined FFR value for each pixel is the ratio of CT value in the vascular region of interest to the reference CT value.