Volumetric Image Intensity Projection via Pixel Weighting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current rendering techniques for volumetric medical image data, such as VIP, can provide false impressions by altering vessel brightness based on distance from the viewing plane, and do not effectively visualize voxel depth, leading to misinterpretation of blood flow and structural visibility.
Innovation Solution
A system that computes initial pixel intensity using methods like MIP or CVP and adjusts it based on voxel location, using pixel weights to enhance foreground visibility and suppress background, allowing for more accurate visualization of volumetric data sets by incorporating a weight unit that computes pixel weights based on distance from the viewing plane.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If VIP technique is used to adjust vessel brightness based on distance from viewing plane, then visibility of foreground structures is enhanced, but false impression of blood flow is created and measurement precision deteriorates
Solution Approach 1:
Instead of adjusting voxel intensities to enhance foreground visibility (as in VIP), the patent inverts the approach by adjusting pixel intensities after the initial rendering. The transfer function modifies pixel values based on the distance of the determining voxel from the viewing plane, thereby achieving foreground enhancement without distorting the original voxel intensity relationships that represent blood flow.
Solution Approach 2:
The patent introduces an intermediary step between voxel intensity computation and final image display. A distance map is computed to store the distance of each pixel's determining voxel from the viewing plane, and this distance information is used as a mediator to modulate pixel intensities through a transfer function, separating the visibility enhancement function from the intensity representation function.
2Illumination intensity
If VIP technique adjusts voxel intensities based on distance, then foreground structure visibility is improved, but computational complexity increases
Solution Approach 1:
The patent performs preliminary computation of a distance map during the rendering process, storing the distance of each pixel's determining voxel from the viewing plane in a separate buffer. This preliminary action allows the subsequent pixel intensity adjustment to use pre-computed distance information, avoiding repeated distance calculations and reducing the computational complexity of the overall process.
3Speed
If current rendering techniques are used, then rendering speed is maintained, but voxel depth information is not visualized and reliability deteriorates
Solution Approach 1:
The patent adds a new dimension to the rendering process by computing and utilizing a distance map that stores the third dimension (distance from viewing plane) for each pixel. This additional dimensional information is then integrated into the pixel intensity computation through the transfer function, enabling depth visualization without sacrificing rendering speed since the distance information is computed once during the initial ray casting process.
Data Source
AI summary
The invention relates to a system (100) for rendering an image based on a volumetric image data set, the system comprising: a computation unit (110) for computing an initial pixel intensity of a pixel of the image, defined by a corresponding voxel intensity of a corresponding voxel comprised in the volumetric image data set; and an adjustment unit (120) for computing a final pixel intensity of the pixel, based on the initial pixel intensity and on a location of the corresponding voxel. Thus, the system of the invention enables new visualizations of volumetric image data sets. Advantageously, unlike a system using the VIP technique, which requires adjusting intensities of voxels comprised in the image data set, the system of the current invention is arranged to adjust intensities of pixels. This reduces the computational complexity of the rendering technique employed by the system relative to the computational complexity of the VIP technique.