Cascaded Diffusion Model for Synthetic Histological Slide Generation

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Solution Overview

Problem

Current machine learning models for cancer diagnostics require large and complete training datasets, which are difficult to assemble due to incomplete modality data, leading to inferior performance with incomplete records.

Innovation Solution

The system generates synthetic histological slide images from RNA-Seq data using a variational autoencoder and diffusion models, transforming RNA-Seq data into a latent space and upsampling to high-resolution images, creating a cascaded diffusion model (RNA-CDM) for multi-cancer RNA-to-image synthesis, which can produce a library of training data for deep learning models.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If large and complete training datasets are used for cancer diagnostics, then diagnostic accuracy is improved, but data availability deteriorates due to incomplete modality data

Engineering Contradiction:
Improvediagnostic accuracyVSAvoiddata availability
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent generates synthetic histological images that replicate the appearance and characteristics of real tissue samples. These synthetic copies are created from RNA-Seq data using diffusion models, providing artificial training data that mimics real-world patterns without requiring additional physical samples. This copying approach directly addresses the data availability problem by creating sufficient training data from existing molecular profiles.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The system performs preliminary data generation by creating synthetic images in advance before they are needed for training deep learning models. The diffusion models are pre-trained to generate realistic histological images from RNA-Seq data, so when training datasets are assembled, complete multi-modal data is already available. This preliminary action eliminates the bottleneck of waiting for complete real-world datasets to be collected.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If deep learning models are trained with incomplete modality data, then training efficiency is improved, but model performance deteriorates

Engineering Contradiction:
Improvetraining efficiencyVSAvoidmodel performance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent introduces synthetic histological images as an intermediary data modality that bridges RNA-Seq molecular data and traditional histological imaging. This intermediary allows deep learning models to be trained on complete multi-modal datasets by providing generated images that correspond to each RNA-Seq sample, enabling the model to learn relationships between molecular profiles and tissue morphology without requiring physical tissue samples for every case.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the parameter space by transforming RNA-Seq data (gene expression levels) into visual image data through the diffusion model. This parameter transformation allows the model to process and integrate multiple data types uniformly, improving training efficiency while maintaining model performance through the realistic generation of histological features from molecular profiles.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If synthetic images are generated from RNA-Seq data, then data completeness is improved, but computational complexity increases

Engineering Contradiction:
Improvedata completenessVSAvoidcomputational complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent segments the image generation process into two distinct computational stages: first, a low-resolution diffusion model generates coarse synthetic images quickly, then a second diffusion model refines these into high-resolution images. This segmentation allows the system to balance computational complexity by performing rough generation efficiently and applying more computationally intensive refinement only when needed, while still achieving complete datasets.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements partial action by generating images at different resolutions based on needs. The first diffusion model produces sufficient low-resolution images for many training purposes, while the second model provides high-resolution versions only when detailed analysis is required. This partial approach reduces overall computational complexity while maintaining data completeness for various application scenarios.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS20240193729A1Systems and Methods for Synthetic Image Generation based on RNA Expression
Publication Date: 2024.06.13 THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIV
  • US20240193729A1 patent drawing
  • US20240193729A1 patent drawing
  • US20240193729A1 patent drawing

AI summary

Systems and methods for synthetic image generation include a method of generating synthetic histological slide images that includes translating each of several RNA-Seq records into a latent space, training a first diffusion model to produce a first synthetic histological slide image at a lower resolution using the translated RNA-Seq records and associated histological slides, training a second diffusion model to upscale lower resolution synthetic histological slide images produced by the first diffusion model to higher resolution synthetic histological slide images, obtaining a given RNA-Seq record, translating the given RNA-Seq record into the latent space, providing the latent representation of the given RNA-Seq record to the trained first diffusion model to generate a given lower resolution synthetic histological slide image, and providing the given lower resolution synthetic histological slide image to the trained second diffusion model to generate a given higher resolution synthetic histological slide image.