MRI Bore Landmark Tracking for 3D Motion Correction

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Solution Overview

Problem

Existing MRI systems face challenges in accurately determining the position of a subject's region of interest due to potential motion artifacts, which affect the quality of medical images, and existing motion correction methods are inadequate for precise alignment and adaptation during the MRI procedure.

Innovation Solution

A method involving a 3D model generation of a subject's region of interest using a 2D camera inside the MRI bore, combined with external 3D data from a depth camera or multiple 2D cameras, to determine the 3D position of the region of interest, enabling both prospective and retrospective motion correction by adjusting MRI parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If optical tracking technology is used for 3D positioning, then positioning accuracy is improved, but device complexity and cost increase

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex optical tracking systems with a simplified electromagnetic field-based positioning system. The MRI system's existing gradient coils and RF system are used to generate electromagnetic fields for positioning, eliminating the need for separate optical cameras, markers, and tracking infrastructure. This substitution maintains positioning accuracy while dramatically reducing device complexity and cost.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If external tracking systems are added to MRI, then 3D positioning capability is improved, but integration complexity and interference risk increase

Engineering Contradiction:
Improve3D positioning capabilityVSAvoidintegration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the positioning function with the existing MRI system by utilizing the gradient coils and RF system for both imaging and positioning purposes. The same electromagnetic field generation hardware serves dual functions, eliminating the need for separate tracking systems and reducing integration complexity. The positioning and imaging operations are coordinated through the existing system control architecture.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If optical markers are placed on patients, then positioning accuracy is improved, but patient comfort and ease of operation worsen

Engineering Contradiction:
Improvepositioning accuracyVSAvoidpatient comfort
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent substitutes optical markers with a non-contact electromagnetic field-based positioning method. The patient's position is determined by measuring their interaction with the MRI system's electromagnetic fields, eliminating the need to attach any physical markers, sensors, or devices to the patient's body. This maintains positioning accuracy while significantly improving patient comfort and ease of operation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP4359811B1Determination of 3D positioning data in an MRI system
Publication Date: 2026.05.20 KONINKLIJKE PHILIPS NV
  • EP4359811B1 patent drawingFigure 1
  • EP4359811B1 patent drawingFigure 2~3
  • EP4359811B1 patent drawing

AI summary

The invention provides means for determining 3D position data in an MRI system. A method for motion correction of MR data, comprising: generating, by a calculation unit (51), a three-dimensional model, 3D model, of a region of interest (24) of a subject (23) comprising at least one landmark (27) inherent to the subject (23) (S10); obtaining, by a first measuring device (20, 25, 52), a two-dimensional image, 2D image, of at least a part of the subject (23) inside a MRI system (22), wherein the measuring device is arranged inside a bore of the MRI system (22) (S20); determining, by the calculation unit (53), at least one landmark (27) in the 2D image, wherein the at least one landmark (27) in the 2D image corresponds to the at least one landmark (27) of the 3D model (S30); determining, by the calculation unit (54), a 3D position of the region of interest (24) of the subject (23) in the MRI system (22) based on the determined at least one landmark (27) in the 2D image (S40); providing, by the calculation unit (55), the 3D position of the region of interest (24) of the subject (23) for motion correction of MR data (S50).