Medical Image Triage Using Two-Stage Normal Filtering

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Solution Overview

Problem

Existing AI-based medical image reading systems face inefficiencies due to high workload for normal images and low sensitivity in distinguishing between weak normal and abnormal cases, leading to increased reader fatigue and reduced overall performance.

Innovation Solution

Implement a two-stage analysis using an abnormality prediction model to filter out 'strong normal' images with high sensitivity and a classification model to differentiate between 'weak normal' and abnormal images, reducing unnecessary reader workload by excluding 'strong normal' images from the worklist.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If deep learning based image recognition is used to automatically detect abnormalities in medical images, then detection capability is improved, but misclassification of normal images as abnormal increases

Engineering Contradiction:
Improveabnormality detection capabilityVSAvoidclassification accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces an intermediary filtering system between image acquisition and reader review. Normal images are automatically filtered out by AI-based abnormality detection, while only suspicious images are forwarded to radiologists. This intermediary layer prevents direct misclassification errors from reaching the final diagnostic workflow, thereby maintaining high detection capability while improving overall reliability through layered verification.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system performs preliminary abnormality screening and classification before images reach the radiologist. By pre-processing images through automated anomaly detection and assigning priority levels, the system prepares images in advance for efficient human review. This preliminary action reduces the burden on radiologists and minimizes the impact of potential misclassifications by having multiple filtering stages ready beforehand.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If all medical images are reviewed by radiologists, then diagnostic accuracy is maintained, but work time and costs increase

Engineering Contradiction:
Improvediagnostic accuracyVSAvoidradiologist work time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts and removes clearly normal images from the radiologist's review workload through automated AI-based classification. By identifying and filtering out normal cases with high confidence, the system extracts only the abnormal or suspicious images that require human expert review. This dramatically reduces radiologist work time while maintaining diagnostic accuracy, as radiologists focus exclusively on cases that need their expertise.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system enables self-service processing where normal images are automatically handled by AI algorithms without requiring radiologist intervention. The automated triage system serves itself by routing images appropriately - normal images are processed and archived automatically, while only uncertain cases are escalated to human reviewers. This self-service approach minimizes time loss while preserving necessary human oversight.

Inventive Principle:
Principle #25Self-service

3Productivity

If priority sorting of images is implemented, then work efficiency is improved, but additional processing steps are required

Engineering Contradiction:
Improveimage review efficiencyVSAvoidsystem processing complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements priority sorting by changing the parameter of image classification from binary (normal/abnormal) to multi-level priority ratings. Images are assigned different priority levels based on the confidence and characteristics of AI detection results. This parameter change enables efficient workflow management where high-priority images are reviewed first, improving productivity without requiring complex additional hardware - only software-based classification layering.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4502830B1Method for filtering normal medical image, method for interpreting medical image, and computing device implementing the methods
Publication Date: 2026.05.13 LUNIT
  • EP4502830B1 patent drawingFigure 1
  • EP4502830B1 patent drawingFigure 2
  • EP4502830B1 patent drawingFigure 3A

AI summary

A computing device comprising: a memory; and at least one processor that executes instructions stored in the memory, wherein the processor is configured to: obtain an abnormality score of a medical image; classify the medical image into normal or abnormal using the abnormality score; and add the medical image to a worklist required to be checked by a reader depending on a classification result.