Adaptive Thresholding for FG Tissue Segmentation in Mammography

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Solution Overview

Problem

Current methods for fibro-glandular tissue segmentation in digital mammography face challenges due to varying breast densities and similarities in brightness patterns between FG tissues and other anatomic structures, leading to inaccurate segmentation, especially in low and high density breasts.

Innovation Solution

An automated method using a fuzzy logic framework that extracts global and specific features from mammography images, applies an unsharp mask and normalization, and configures a fuzzy logic module to compute an adaptive threshold for accurate FG tissue segmentation, accounting for varying breast densities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a constant threshold method is used for FG tissue segmentation, then the device complexity is low, but the segmentation accuracy deteriorates (67.4% accuracy)

Engineering Contradiction:
Improvesegmentation accuracyVSAvoidsegmentation method complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements an adaptive thresholding mechanism that dynamically adjusts segmentation thresholds based on local image characteristics and breast density estimates. Instead of using a fixed constant threshold, the system calculates density-specific thresholds that adapt to varying tissue densities across different regions of the mammogram, thereby improving segmentation accuracy while managing complexity through automated adaptation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the threshold parameter from a constant value to a density-dependent variable. By estimating breast density first and then selecting thresholds based on the estimated density category (fatty, glandular, or dense), the system optimizes segmentation accuracy for different tissue types. This parameter change allows the same segmentation algorithm to perform well across diverse breast densities.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If breast density variation is considered in segmentation, then segmentation accuracy improves, but the difficulty of detecting and measuring increases

Engineering Contradiction:
Improvesegmentation accuracy in low-density breastsVSAvoiddifficulty of FG tissue detection
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent performs preliminary breast density estimation before conducting FG tissue segmentation. By first categorizing the breast density (fatty, glandular, or dense) using global image features and histograms, the system prepares density-appropriate parameters and thresholds in advance. This preliminary action simplifies the subsequent segmentation step by providing density-specific guidance, thereby reducing the overall difficulty of detection despite considering density variations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces breast density estimation as an intermediary step between image acquisition and FG tissue segmentation. This intermediary process uses global image characteristics to determine tissue density, which then guides the segmentation process by providing density-specific thresholds and parameters. This mediator simplifies the complex task of segmenting across all densities by breaking it into manageable density-specific subtasks.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If fuzzy logic module is configured with manual settings, then the reliability of segmentation improves, but the ease of operation deteriorates

Engineering Contradiction:
Improvesegmentation reliabilityVSAvoidsystem configuration ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent implements automated configuration of the fuzzy logic module that performs self-calibration using training data. The system automatically learns optimal membership functions and rule parameters from labeled mammogram images, eliminating the need for manual expert configuration. This self-service approach maintains high reliability through data-driven optimization while significantly improving ease of operation by removing manual setup requirements.

Inventive Principle:
Principle #25Self-service

4Measurement precision

If feature extraction and fuzzy logic processing are applied, then segmentation accuracy improves, but processing time increases

Engineering Contradiction:
Improvesegmentation accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent divides the processing pipeline into distinct modular stages: breast density estimation, feature extraction, fuzzy logic inference, and final segmentation. Each stage processes specific features and produces intermediate results that feed into the next stage. This segmentation of processing allows for optimized computation at each step and enables parallel processing where applicable, reducing overall processing time while maintaining accuracy.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS9918686B2Automated fibro-glandular (FG) tissue segmentation in digital mammography using fuzzy logic
Publication Date: 2018.03.20 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • US9918686B2 patent drawing
  • US9918686B2 patent drawing
  • US9918686B2 patent drawing

AI summary

Embodiments of the present invention provide automated systems and methods for segmentation of fibro-glandular (FG) tissue in digital mammography. A classifier is trained for breast density without the prior knowledge for FG tissue. The classifier is then used for feature selection, where the selected features are fed into a fuzzy logic module, and an adaptive threshold is obtained. Post-processing is performed on the image in order to reduce regions which may have been misclassified during the FG segmentation.