MRI-PET Attenuation Map Generation via Localized Sequence Adaptation
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Solution Overview
Problem
Current MRI-PET systems face challenges in creating accurate attenuation maps due to limitations in the MRI magnetic gradient field and B0 field homogeneity, leading to distorted images and prolonged scan times, especially when imaging patients with extremities outside the maximum field of view.
Innovation Solution
The method involves acquiring and merging projection data in axial directions to adapt sequence parameters for MRI scans, allowing for patient-specific mapping and distortion correction, thereby enhancing image quality and reducing scan duration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the scan region is extended to include patient extremities in the peripheral region, then the coverage area is improved, but image distortion increases due to B0 field inhomogeneity and gradient non-linearity
Solution Approach 1:
The patent divides the scan region into a central region and a peripheral region, applying different sequence parameters to each. The central region uses standard parameters while the peripheral region uses adapted parameters to compensate for distortion, allowing extended coverage without sacrificing image quality in critical areas.
Solution Approach 2:
The patent implements location-specific sequence parameter adaptation where the MRI sequence parameters are modified based on the spatial location within the field of view. Peripheral regions experiencing distortion receive corrected parameters while central regions maintain standard parameters, optimizing image quality locally across the entire scan region.
2Area of stationary object
If the maximum field of view is used to cover the entire patient body, then the coverage is improved, but image quality deteriorates in peripheral regions
Solution Approach 1:
The patent applies different sequence parameters to different spatial locations within the field of view. Central regions use standard parameters for optimal image quality while peripheral regions use adapted parameters to compensate for distortion effects, enabling full body coverage without sacrificing image quality anywhere.
Solution Approach 2:
The patent dynamically adapts sequence parameters based on the patient's anatomy and position. The system determines patient-specific mapping and adjusts parameters in real-time during the imaging process, allowing the scan to accommodate varying patient geometries while maintaining image quality across the entire field of view.
3Manufacturing precision
If patient-specific mapping and parameter adaptation are implemented, then image quality is improved, but processing complexity increases
Solution Approach 1:
The patent performs patient-specific mapping and determines optimal sequence parameters in advance, before the actual attenuation map generation. This preliminary processing allows the system to pre-calculate distortion corrections and parameter adaptations, reducing real-time processing complexity while maintaining high image quality.
Solution Approach 2:
The system automatically determines patient anatomy and adapts parameters without requiring manual intervention. The patient-specific mapping is generated autonomously from the imaging data, and the sequence parameter optimization is performed self-service by the system's processing algorithms, reducing operator burden despite increased processing requirements.
Data Source
AI summary
A method is for providing an attenuation map of a patient, suitable for correcting PET data of the patient acquired with combined magnetic resonance/positron emission tomography imaging in a magnetic resonance/positron emission tomography system. In an embodiment, the method includes acquiring magnetic resonance data with at least one imaging scan in the magnetic resonance/positron emission tomography system; determining the attenuation map of the patient using the magnetic resonance data and providing the attenuation map of the patient for correcting the PET data of the patient acquired with combined magnetic resonance/positron emission tomography imaging.