Divergent Gradient Field for Real-Time MR-Guided Radiotherapy
Solution Overview
Problem
Magnetic resonance guided radiotherapy systems face challenges in generating real-time Beam's Eye View (BEV) images due to the computationally intensive processing required, leading to potential targeting errors and unnecessary radiation exposure, especially with MRI's higher data acquisition needs compared to CT.
Innovation Solution
An integrated MR-radiotherapy hybrid system with a radiation source and an MRI apparatus configured to generate a divergent gradient field matching the divergent geometry of the radiation beam, allowing for real-time imaging and accurate targeting decisions based on a divergent perspective.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If CT data is processed in real-time to generate BEV images, then real-time IGRT is achieved, but computational complexity becomes too intensive
Solution Approach 1:
The patent replaces the conventional mechanical approach of ray-tracing through 3D CT datasets with a mathematical projection method that directly calculates BEV images from 2D projection data, eliminating computationally intensive 3D reconstruction processes while maintaining real-time capability
Solution Approach 2:
The patent creates a simplified mathematical model that copies the essential geometric relationships of the divergent beam geometry without requiring full 3D dataset reconstruction, enabling real-time BEV image generation from projected data
2Productivity
If MRI data acquisition is performed with standard slice thickness, then data collection is efficient, but targeting precision decreases due to beam divergence mismatch
Solution Approach 1:
The patent changes the encoding gradient parameters in the direction of beam divergence to match the divergent geometry of the radiation beam, transforming standard MRI slice encoding into a divergent geometry-matched encoding scheme that improves targeting precision without reducing acquisition efficiency
Solution Approach 2:
The patent introduces asymmetric encoding gradient configurations that align with the asymmetric divergent beam geometry, where gradient strength varies along the beam path to match the increasing beam spread, improving the accuracy of beam path visualization
3Ease of operation
If standard MRI encoding gradients are used, then image acquisition is straightforward, but beam path visualization accuracy deteriorates
Solution Approach 1:
The patent modifies the encoding gradient parameters to create a divergent geometry-matched encoding scheme that maintains operational simplicity while improving beam path visualization accuracy through optimized gradient configurations
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
This configuration enables more precise targeting of tumor tissue while minimizing radiation to healthy tissues, reducing adverse side effects and improving the completeness of treatment by aligning image pixels with the divergent path of the treatment beam.
Implementation Method 1
an MR imaging (MRI) apparatus configured to generate a divergent gradient field shaped to match a divergent geometry of the radiation beam
Data Source
AI summary
A magnetic resonance (MR)-radiotherapy (RT) hybrid system for treating a patient is disclosed. The MR-RT hybrid system includes a radiation source for supplying a radiation beam to treat the patient and an MR imaging (MRI) apparatus for generating a divergent gradient field shaped to match a divergent geometry of the radiation beam of the radiation source.