Resonance Raman MRI Contrast Agents for Multimodal Imaging
Solution Overview
Problem
Current methods face challenges in spatially correlating MRI and optical images due to tissue movement or changes during surgeries, and existing ionization techniques for laser plumes are inefficient for mass spectrometry analysis of fragile biological molecules.
Innovation Solution
A method utilizing a chelated ion MRI contrast agent for simultaneous MRI and optical imaging through resonance Raman spectroscopy, and a mass spectrometry system with atmospheric pressure chemical ionization to efficiently ionize laser plumes by intercepting them with an ionized gas jet containing dopant molecules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If frequent MRI scanning is performed to capture tissue position changes during surgery, then spatial correlation between MRI and optical images is improved, but imaging time and operational complexity increase significantly
Solution Approach 1:
The patent applies a dual-modal contrast agent that provides both MRI and Raman optical imaging contrast simultaneously. This allows the same agent to serve multiple imaging functions, enabling spatial correlation between MRI and optical images without requiring separate contrast agents or frequent re-scanning, thus resolving the contradiction between measurement precision and time loss
2Quantity of substance
If standard ionization techniques are used for laser ablation plumes, then molecular desorption is achieved, but excessive energy input causes fragmentation of fragile biological molecules
Solution Approach 1:
The patent introduces a buffer gas as an intermediary medium between the laser ablation plume and the ionization process. The buffer gas molecules absorb excess energy from the laser plume and transfer it gradually, preventing direct excessive energy input to fragile biological molecules while still achieving efficient molecular desorption and ionization
3Measurement precision
If existing multimodal contrast agents combining MRI and optical modalities are used, then spatial correlation between imaging modalities is improved, but device complexity and clinical translation uncertainty increase due to nanoparticle requirements
Solution Approach 1:
The patent employs conventional small-molecule chelated ion MRI contrast agents (such as gadolinium-based agents) that are already clinically approved and widely used, rather than complex nanoparticle-based contrast agents. These smaller molecules are easier to manufacture, have known safety profiles, and can be rapidly translated to clinical use while still providing both MRI and Raman optical imaging contrast
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
Enables precise spatial correlation of MRI and optical images, facilitating guided tumor resection and efficient analysis of molecular composition with minimal energy input, improving imaging accuracy and data correlation.
Implementation Method 1
illuminating the tissue with excitation light that has spectral components that are approximately tuned close to one of the charge-transfer electronic transitions of the contrast agent such that interaction of the excitation light with the charge-transfer electronic transitions produce Raman optical signals that are enhanced due to resonance effects
Implementation Method 2
a gas delivery system for delivering a gas jet to the ablation plume, wherein the gas jet contains dopant molecules; a metal object with a sharp tip placed in the vicinity of the gas jet. The system includes a high voltage generator that is electrically connected to the metal object thereby creating a corona discharge at the sharp tip, wherein the corona discharge ionizes the dopant molecules in the gas jet
Data Source
AI summary
Disclosed herein is a method for multimodal imaging during a medical procedure using magnetic resonance imaging (MRI) and Raman optical imaging which involves administering an MRI imaging contrast agent that a chemical structure having charge-transfer electronic transitions. The tissue is imaged using and MRI device and the tissue is illuminated with excitation light that has spectral components that are approximately tuned close to one of the charge-transfer electronic transitions thereby producing enhanced Raman optical signals which are analyzed to produce Raman imaging data followed by registering the MRI and Raman imaging data. The present disclosure also provides a method for ionizing laser plumes through atmospheric pressure chemical ionization.