Discrete Gamma Ray Sampling for CT Artifact Reduction

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Solution Overview

Problem

Medical imaging systems, such as computed tomography systems, face artifacts in reconstructed images due to limited-angle acquisition ranges, which result in unsampled angular regions and incomplete data.

Innovation Solution

The system employs an angularly discrete acquisition technique by dividing the angular range into multiple discrete continuous acquisition ranges separated by unsampled ranges, allowing for incomplete data collection and subsequent reconstruction without continuous scanning, using multiple detectors and practical features like patient supports to manage rotation and data sampling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If a limited-angle acquisition range is used, then the scanning time is reduced, but reconstruction artifacts appear in the images

Engineering Contradiction:

Improvescanning timeVSAvoidimage quality

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The angular range is divided into multiple discrete continuous acquisition ranges separated by unsampled angular ranges. This segmentation allows the system to acquire data in multiple segments rather than requiring a continuous full angular scan, thereby reducing total scanning time while managing the trade-off with image quality through selective sampling.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system performs partial angular sampling by acquiring data only in specific discrete angular ranges rather than continuously across the full angular range. This partial action approach reduces scanning time while the reconstruction algorithm compensates for the missing data through iterative methods that can handle incomplete sampling.

Inventive Principle:

Principle #16Partial or excessive action

2Measurement precision

If multiple discrete continuous acquisition ranges are used, then the angular sampling coverage is improved, but the device complexity increases

Engineering Contradiction:

Improveangular sampling coverageVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The angular range is segmented into multiple discrete continuous acquisition ranges that can be sequentially acquired. This segmentation improves angular sampling coverage by distributing measurements across multiple ranges while managing device complexity through a systematic approach to data acquisition and reconstruction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system employs periodic action by rotating through multiple discrete angular ranges in a structured sequence. This periodic acquisition pattern improves angular sampling coverage while maintaining manageable device complexity through regular, repeating measurement cycles that can be efficiently controlled and reconstructed.

Inventive Principle:

Principle #19Periodic action

3Adaptability or versatility

If the angular range is divided into discrete acquisition ranges, then the data acquisition flexibility is improved, but the manufacturing precision requirements increase

Engineering Contradiction:

Improvedata acquisition flexibilityVSAvoidangular positioning accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

Dividing the angular range into discrete continuous acquisition ranges provides flexibility in data acquisition by allowing selective sampling of specific angular regions. This segmentation improves adaptability while the system manages manufacturing precision requirements through consistent rotational positioning and systematic data collection protocols.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system changes acquisition parameters by selecting different discrete angular ranges for data collection. This parameter change approach improves data acquisition flexibility by adapting to different scanning requirements while maintaining manageable precision requirements through standardized measurement procedures and reconstruction algorithms.

Inventive Principle:

Principle #35Parameter changes

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 enables artifact-free image reconstruction up to specific angular frequencies, allowing for higher-frequency information acquisition and accommodating practical system constraints, such as limited rotation and multiple detector heads, while reducing the size of unsampled regions.

Implementation Method 1

a radiation detector that detects radiation from a source

Methodology Applied

Scientific EffectGamma ray detection: Absorption (EM radiation)

Data Source

PatentUS7668288B2Discrete sampling of gamma ray field over multiple portions using multiple heads with spaces between the different portions

Publication Date: 2010.02.23 DIGIRAD HEALTH INC

AI summary

A medical imaging system, e.g., a computed tomography system includes at least one radiation detector that is relatively rotatable with respect to an object of interest. The angular range is divided into discrete continuous acquisition ranges and unsampled angular ranges, wherein the discrete continuous acquisition ranges are separated by unsampled angular ranges.