Multi-Pass CT Scanning With Offset Detectors for Large FOV Imaging

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Solution Overview

Problem

Conventional CT imaging systems, particularly those used in radiotherapy, face challenges in achieving high-quality images with reduced artifacts and faster scanning times, especially when using helical scans, due to limitations in gantry rotation and detector configuration.

Innovation Solution

A multi-pass scan methodology utilizing a low-energy radiation source for imaging and a high-energy radiation source for therapy, combined with a helical scan trajectory, allows for continuous image acquisition with improved tissue contrast and reduced scatter, using a collimated beam and dynamic collimation to optimize detector exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a single large-diameter detector array is used to cover a wide area, then the field of view is improved, but the detector complexity and manufacturing difficulty increase significantly

Engineering Contradiction:
Improvedetector array areaVSAvoiddetector array complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent divides the detector array into multiple smaller detector arrays arranged in a curved configuration. Each detector array has a limited field of view, but collectively they cover a wide area through their curved arrangement. This segmentation reduces the complexity of individual detector arrays while achieving the same total coverage area.

Inventive Principle:
Principle #1Segmentation

2Area of stationary object

If multiple detector arrays are used to cover a wide area, then the field of view is improved, but the number of components and system complexity increase

Engineering Contradiction:
Improvedetector coverage areaVSAvoidnumber of detector arrays
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent combines multiple detector arrays into a single integrated curved detector array assembly. The multiple detector arrays are positioned and configured to work together as one unified detection system, with their individual fields of view overlapping or adjacent to cover a wide area. This merging approach maintains the wide coverage benefit while reducing system complexity compared to using completely separate detector systems.

Inventive Principle:
Principle #5Merging (Combining)

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

This approach enhances image quality and scanning speed, reducing artifacts and scatter, while optimizing workflow by segmenting scans into multiple passes to meet different image quality and dose requirements for registration and treatment planning.

Implementation Method 1

an X-ray tube to generate X-ray waves

Methodology Applied
Scientific EffectX-ray generation: X-Ray

Implementation Method 2

a detector array to detect the X-ray waves and generate a set of projection data

Methodology Applied
Scientific EffectX-ray attenuation detection: X-Ray

Data Source

PatentEP3886709B1Multi-pass computed tomography scans for improved workflow and performance
Publication Date: 2026.04.29 ACCURAY LLC
  • EP3886709B1 patent drawingFigure 1
  • EP3886709B1 patent drawingFigure 2
  • EP3886709B1 patent drawingFigure 3~5

AI summary

An x-ray imaging apparatus and associated methods are provided to execute multi-pass imaging scans for improved quality and workflow. An imaging scan can be segmented into multiple passes that are faster than the full imaging scan. Data received by an initial scan pass can be utilized early in the workflow and of sufficient quality for treatment setup, including while the another scan pass is executed to generate data needed for higher quality images, which may be needed for treatment planning. In one embodiment, a data acquisition and reconstruction technique is used when the detector is offset in the channel and/or axial direction for a large FOV during multiple passes.