Detector Uniformity Map Calibration via Localized Flood Sources

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Solution Overview

Problem

In nuclear medicine imaging, detectors with large field of views face sensitivity variations due to inconsistencies in electronics, crystals, and collimators, making it inconvenient to update isotope-specific uniformity maps using large flood sources.

Innovation Solution

A method and system that utilize a smaller flood source to update uniformity maps by positioning it on a sub-portion of the detector surface, collecting counts, and normalizing local uniformity maps to replace adjustment portions of the existing map, allowing for efficient recalibration of detector portions without the need for a full detector recalibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a large flood source is used to update uniformity maps for the entire detector, then complete calibration coverage is achieved, but the calibration process becomes inconvenient and impractical

Engineering Contradiction:

Improveuniformity map calibration accuracyVSAvoidcalibration convenience

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent divides the detector surface into multiple sub-portions and uses a smaller flood source to calibrate each sub-portion separately. The uniformity map is updated in segments corresponding to these sub-portions, allowing practical calibration while maintaining complete coverage through multiple localized measurements

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of requiring a flood source larger than the entire detector, the patent uses a smaller flood source that covers only sub-portions of the detector at a time. By performing multiple partial calibrations across different sub-portions, the complete uniformity map is updated without needing an excessively large flood source

Inventive Principle:

Principle #16Partial or excessive action

2Ease of operation

If a smaller flood source is used to update only sub-portions of the detector, then calibration convenience is improved, but complete detector coverage is not achieved

Engineering Contradiction:

Improvecalibration convenienceVSAvoiduniformity map calibration accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The detector surface is divided into multiple sub-portions, each calibrated separately using the smaller flood source. The uniformity map is segmented and updated for each sub-portion, ensuring complete coverage while maintaining the convenience of using a smaller flood source

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The calibration process is performed in periodic steps, where the smaller flood source systematically moves to or is repositioned for different sub-portions of the detector. Each periodic action calibrates a specific sub-portion, and after all sub-portions are calibrated, the complete uniformity map is updated

Inventive Principle:

Principle #19Periodic action

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 simplifies and speeds up the calibration process, reduces costs, and improves ease of use by allowing on-site recalibration of detector portions, maintaining the integrity of the overall detector performance.

Implementation Method 1

collecting counts from the flood for the sub-portion of the detector surface area

Methodology Applied

Scientific EffectRadiation detection: Absorption (EM radiation)

Data Source

PatentUS11543546B2Systems and methods for localized calibration

Publication Date: 2023.01.03 GE PRECISION HEALTHCARE LLC

AI summary

A method is provided for updating a uniformity map of a detector. The detector defines a detector surface area. The method includes positioning a flood on a sub-portion of the detector surface area of the detector. The flood defines a flood area that is smaller than the detector surface area. Also, the method includes collecting counts from the flood for the sub-portion of the detector surface area. Further, the method includes updating an adjustment portion of the uniformity map using the counts collected for the sub-portion of the detector surface area, wherein the adjustment portion corresponds to at least a part of the sub-portion of the detector surface area.