Material-Specific Attenuation Maps for PET-MR Hardware Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current combined imaging systems face challenges in generating accurate attenuation maps, particularly when integrating MR hardware into PET systems, due to MR hardware causing attenuation within the PET field of view and the use of linear scaling factors that fail to account for non-organic materials, requiring point sources for spatial orientation.
Innovation Solution
A method and system that utilize CT scan data to identify materials in each voxel, calculate voxel attenuation values, and generate a material-specific attenuation map, which is then registered to the coordinate system of the second imaging modality, enhancing accuracy and correcting attenuation in PET imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a linear scaling factor is used to generate attenuation values for PET attenuation correction, then the process is simple and fast, but the accuracy is poor especially for non-organic materials
Solution Approach 1:
The patent changes the parameter representation from a single linear scaling factor to a multi-parameter material classification system. By identifying different material types (organic, non-organic, bone, soft tissue) and assigning specific attenuation coefficients to each, the system achieves both accuracy for diverse materials and computational efficiency through standardized coefficient values.
2Measurement precision
If point sources are attached to hardware elements for spatial orientation, then spatial alignment is achieved, but the system complexity increases
Solution Approach 1:
The imaging system performs self-alignment by using its own imaging components as reference objects. The attenuation map is generated from images of the imaging components themselves, eliminating the need for external point sources or separate alignment procedures. The system services its own spatial orientation needs through integrated attenuation mapping.
3Adaptability or versatility
If MR hardware is integrated into PET system, then combined imaging capability is improved, but attenuation within PET field of view increases
Solution Approach 1:
The patent converts the harmful attenuation effect of MR hardware into a beneficial feature by using the MR hardware itself as the reference object for generating the attenuation map. The same components that cause attenuation are used to characterize and correct for that attenuation, transforming a problem into a solution.
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
The method provides higher accuracy attenuation maps, especially for non-organic materials like metal implants, improving attenuation correction in combined imaging systems.
Implementation Method 1
receiving computed tomography scan data including an imaging component. The CT scan data comprises a plurality of voxels each having a scanned CT value
Implementation Method 2
The projection data may then be used to generate an attenuation map of the imaged object using a Beer-Lambert law based algorithm
Data Source
AI summary
Systems and methods of generating an attenuation map are disclosed. Computed tomography (CT) scan data for a CT scan including an imaging component is obtained. The CT scan data comprises a plurality of voxels each having a scanned CT value. A material in each voxel of the plurality of voxels is identified by comparing the scanned CT value for the voxel with predetermined CT values for a plurality of materials and a voxel attenuation value for each voxel is determined based on the predetermined CT value for the identified material. An attenuation map including the determined voxel attenuation value for each voxel is generated. The attenuation map is configured for attenuation correction of an imaging modality including the imaging component with a field of view of the imaging modality.