Complementary-Ray CT Reconstruction for Consecutive Missing Views

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Solution Overview

Problem

Existing CT reconstruction methods struggle to effectively handle consecutive missing views, leading to image degradation such as streaking and shading due to insufficient interpolation, especially when a large number of views are missing.

Innovation Solution

Utilize complementary rays from previous or subsequent views to fill in missing views, employing linear or non-linear combinations and smoothing weights to prevent over-emphasis, and adjust for shifts in detected rays using weighted averages of neighboring channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If interpolation is performed to fill missing views, then image reconstruction can proceed, but image quality degrades with streaking and shading artifacts when many views are missing

Engineering Contradiction:

Improveimage reconstruction capabilityVSAvoidimage quality

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent creates a copy of the projection data from available views and uses back-projection to generate synthetic projection data that fills in the missing views. This copying approach allows the reconstruction algorithm to proceed with complete view data while maintaining image quality by deriving the missing data from actual measured projections rather than simple interpolation

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical interpolation process with a computational back-projection process. Instead of mechanically interpolating missing view data using adjacent views, the system uses iterative back-projection algorithms to computationally generate the missing projection data, achieving superior image quality without the artifacts of traditional interpolation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If linear interpolation is used to fill missing views, then the reconstruction process is simple and fast, but artifacts appear in the reconstructed image

Engineering Contradiction:

Improvereconstruction speedVSAvoidimage quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent substitutes the simple linear interpolation mechanism with a more sophisticated back-projection computational mechanism. This replacement maintains computational efficiency while dramatically improving image quality by using the actual geometric relationships in CT data to generate missing views rather than simple linear averaging

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transforms the problem from a one-dimensional interpolation task (filling missing view angles) into a two-dimensional back-projection task (reconstructing the object from multiple projections and re-projecting). This dimensional transformation allows the system to leverage redundant information from multiple projection angles to accurately recover missing data

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS12412321B2Method and system to compensate for consecutive missing views in computed tomography (CT) reconstruction

Publication Date: 2025.09.09 CANON MEDICAL SYST CORP

AI summary

A method, system, and computer readable medium to compensate for consecutive missing views in Computed Tomography (CT) reconstruction. By utilizing at least one complementary ray from a previous or subsequent view, the missing view(s) can be filled in. When plural complementary rays exist, a linear or non-linear combination of rays can be used to fill in the missing views, and the weights used in the combination may be smoothed to prevent over-emphasis of the replacement views.