Selective Size Imaging via Diffusion Times for Tumor Differentiation

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Solution Overview

Problem

Current imaging methods for brain tumors, such as those using gadolinium-based contrast agents, face challenges in accurately distinguishing tumors from radionecrosis and other lesions, particularly in patients with renal dysfunction, due to limitations in differentiating cell types and potential radiation damage during stereotactic radiosurgery treatment.

Innovation Solution

The Selective Size Imaging using Filters via Diffusion Times (SSIFT) method, which employs multiple diffusion MRI scans with varying diffusion times to calculate incremental area under curve values, allowing for the generation of images that differentiate cell sizes and effectively distinguish tumors from surrounding tissues and radionecrosis without the need for exogenous contrast agents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If gadolinium-based contrast agents are used for tumor imaging, then tumor visibility is improved, but patient safety deteriorates due to nephrogenic systemic fibrosis in renal dysfunction patients and gadolinium deposition in the brain

Engineering Contradiction:
Improvetumor visibilityVSAvoidpatient safety
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and eliminates the harmful gadolinium contrast agent from the imaging process, replacing it with a safe diffusion-based method that achieves tumor visualization without introducing toxic substances into the patient's body

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The method utilizes the natural diffusion properties of water molecules within tissue as the contrast mechanism, eliminating the need for external contrast agents. The biological system's own physical properties are harnessed to provide the necessary imaging contrast

Inventive Principle:
Principle #25Self-service

2Difficulty of detecting and measuring

If gadolinium-based contrast agents are used for tumor imaging, then tumor detection capability is improved, but diagnostic accuracy deteriorates because gadolinium-MRIs only identify cell growths that break the blood brain barrier

Engineering Contradiction:
Improvetumor detection capabilityVSAvoiddiagnostic accuracy
Core Design Contradiction:
Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The invention changes the imaging parameter from blood-brain barrier permeability (gadolinium enhancement) to water diffusion characteristics. By measuring diffusion coefficients and applying the diffusion filter, the method detects tumors based on their intrinsic diffusion properties rather than contrast agent uptake, enabling detection of tumors that do not break the blood-brain barrier

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If diffusion-weighted MRI is used to identify areas of interest, then tissue microstructure detection is improved, but differentiation between tumors and radionecrosis deteriorates

Engineering Contradiction:
Improvetissue microstructure detectionVSAvoidtissue type differentiation
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The invention introduces dynamic diffusion time variation to enhance tissue differentiation. By acquiring diffusion data at multiple time points and applying temporal filtering, the method exploits differences in how tumors and radionecrosis evolve over diffusion time, providing dynamic contrast that enables reliable tissue type identification

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The method uses the diffusion time dependency of the diffusion filter as a feedback mechanism to enhance contrast between tumor and radionecrosis. The filter responds differently to various tissue types based on their diffusion characteristics across time, providing feedback that improves differentiation capability

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

SSIFT provides high-resolution, non-invasive imaging capable of accurately differentiating tumors from radionecrosis and other brain etiologies, enhancing treatment planning and reducing unnecessary radiation exposure, while being suitable for patients with renal dysfunction and operating within existing clinical MRI hardware.

Implementation Method 1

mapping the diffusion of water molecules to generate contrast in MRI images and identify different tissue microstructures

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentUS10712419B2Selective size imaging using filters via diffusion times
Publication Date: 2020.07.14 VANDERBILT UNIV
  • US10712419B2 patent drawing
  • US10712419B2 patent drawing
  • US10712419B2 patent drawing

AI summary

Systems and methods for cell size imaging using MRI systems are provided. An exemplary method includes obtaining first diffusion MRI data for biological tissues of interest and at least one second diffusion MRI data for the biological tissues of interest having a different diffusion time than the first diffusion MRI data. The method also includes calculating, from the first and at least one second diffusion MRI data, incremental area under curve values of the first and at least one second diffusion MRI data for a chosen diffusion time range. Thereafter, an image for the biological tissues of interest is generated, wherein intensity values for each of the plurality of image voxels is based on a corresponding one of the incremental area under curve values.