PD-L1 Cell Classification via Nuclear and Contextual Metrics

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Solution Overview

Problem

Automated identification of biological structures in histopathology images, particularly the classification and quantification of PD-L1 tumor cells, is challenging due to the large size of whole slide images and the complexity of detecting and distinguishing between different cell types and staining patterns, which is difficult for pathologists to perform manually.

Innovation Solution

A computer system that classifies cells in tissue samples stained for the PD-L1 biomarker by computing nuclear features and deriving contextual information metrics from image texture features surrounding the nucleus, using methods such as Haralick features, texton histograms, and gradient orientation, to improve classification accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual assessment of cells in whole slide images is performed by pathologists, then diagnostic accuracy can be maintained, but the process becomes extremely time-consuming and impractical due to the large number of cells (order of 10^4) present in whole slide tissue images

Engineering Contradiction:
Improveclassification speedVSAvoidclassification accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent segments the classification task into two distinct stages: (1) extracting nuclear features from individual cell nuclei, and (2) deriving contextual information metrics from image texture features surrounding each nucleus. This segmentation allows automated processing of large numbers of cells while maintaining diagnostic accuracy by preserving both individual cell characteristics and their spatial relationships.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from analyzing only individual nuclear features to incorporating a second dimension of analysis by deriving contextual information metrics from the spatial arrangement and texture patterns of surrounding cells. This dimensional expansion enables the system to capture tissue architecture information that improves classification accuracy while maintaining high throughput.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If only nuclear features are used for cell classification, then the classification process remains simple and fast, but classification accuracy is insufficient for distinguishing between different cell types in complex tissue contexts

Engineering Contradiction:
Improveclassification accuracyVSAvoidfeature extraction complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by deriving contextual information metrics specifically from the local neighborhood surrounding each nucleus rather than analyzing the entire image uniformly. This localized approach captures tissue architecture and cellular arrangement patterns that are relevant to each specific cell's classification while keeping computational complexity manageable through focused analysis.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent adds a second analytical dimension by incorporating image texture features and spatial arrangement information alongside traditional nuclear features. This multi-dimensional feature space includes both intrinsic nuclear properties and extrinsic contextual information, enabling more accurate classification of complex cell types without excessive complexity increase.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If automated analysis is implemented using only simple nuclear feature extraction, then processing speed increases, but the system cannot accurately distinguish between different cell types and staining patterns in complex tissue environments

Engineering Contradiction:
Improvecell type differentiation accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments the feature extraction process into efficient nuclear feature extraction (maintaining speed) and contextual information derivation (improving accuracy). By processing these segments in a structured pipeline and utilizing computational optimizations, the system achieves both rapid processing and accurate cell type differentiation in complex tissue environments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the parameters of analysis by incorporating multiple types of features (nuclear morphology, staining intensity, spatial arrangement, texture patterns) rather than relying on a single parameter set. This multi-parameter approach enables accurate differentiation of cell types while maintaining processing efficiency through optimized computational methods.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3218843B1Classifying nuclei in histology images
Publication Date: 2024.04.24 VENTANA MEDICAL SYSTEMS INC
  • EP3218843B1 patent drawingFigure 1A
  • EP3218843B1 patent drawingFigure 1B
  • EP3218843B1 patent drawingFigure 1C

AI summary

Disclosed is a computer device (14) and computer-implemented method of classifying cells within an image of a tissue sample comprising (1) providing the image of the tissue sample as input; (2) computing (111) nuclear feature metrics from features of nuclei within the image; (3) computing (112) contextual information metrics based on nuclei of interest with the image; (4) classifying (113) the cells within the image using a combination of the nuclear feature metrics and contextual information metrics.