CT Implant Artifact Detection via Voxel Clustering

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Solution Overview

Problem

X-ray computed tomography (CT) imaging often produces artifacts from implants like metals and ceramics, which obscure underlying anatomy and complicate critical assessments or therapy evaluations due to high attenuation coefficients and scatter effects, making existing artifact reduction methods computationally complex and difficult to implement in real-time imaging environments.

Innovation Solution

A system and method that identify implant artifacts in CT slices by comparing voxel characteristics with an implant database to determine a best-fit implant, overlaying a registered graphical image of the implant on the artifact for correction, which is performed as a post-processing operation using a processor and memory to enhance image clarity and accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional artifact reduction methods are used to correct implant-related artifacts in CT images, then image quality is improved, but computational complexity increases and real-time implementation becomes difficult

Engineering Contradiction:
Improveimage qualityVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system pre-scan the patient to identify implant locations and characteristics before the actual CT scan. This preliminary action allows the main scanning process to proceed without real-time artifact correction computations, thereby reducing computational complexity during the critical imaging phase while still achieving high image quality through subsequent processing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The artifact correction process is divided into separate stages: implant identification through pre-scan, artifact characterization, and final image reconstruction. This segmentation allows each stage to be optimized independently, reducing the computational burden on any single system component while maintaining overall image quality.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If real-time artifact correction is implemented during CT scanning, then image clarity is improved, but scanning time and system complexity increase

Engineering Contradiction:
Improveimage clarityVSAvoidscanning time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs implant identification and artifact characterization in a pre-scan phase before the main clinical CT scan. This preliminary action ensures that when the actual scan is performed, the artifact correction parameters are already determined, allowing for rapid processing without extending the critical scanning time.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If detailed implant identification is performed to accurately correct artifacts, then assessment accuracy is improved, but processing complexity increases

Engineering Contradiction:
Improveassessment accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses the implant's own characteristics (such as its artifact signature in the pre-scan) to identify and characterize itself. By analyzing the artifact pattern produced by the implant, the system automatically determines implant type, location, and orientation without requiring complex external identification procedures, thereby maintaining high assessment accuracy while reducing processing complexity.

Inventive Principle:
Principle #25Self-service

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 effectively corrects implant-related artifacts in 3D CT images, improving the assessment of implant positioning and underlying anatomy, facilitating more accurate surgical planning and evaluation by separating the correction process from real-time scanning, allowing for precise identification and visualization of implant positions and orientations.

Implementation Method 1

X-ray computed tomography (CT) imaging often produces artifacts from implants like metals and ceramics, which obscure underlying anatomy and complicate critical assessments or therapy evaluations due to high attenuation coefficients and scatter effects

Methodology Applied
Scientific EffectX-Ray attenuation: Absorption (EM radiation)

Implementation Method 2

A system and method that identify implant artifacts in CT slices by comparing voxel characteristics with an implant database to determine a best-fit implant, overlaying a registered graphical image of the implant on the artifact for correction

Methodology Applied
Scientific EffectImage Processing:

Data Source

PatentEP3486873B1Automatic implant detection from image artifacts
Publication Date: 2020.11.18 MEDTRONIC NAVIGATION INC
  • EP3486873B1 patent drawingFigure 1
  • EP3486873B1 patent drawingFigure 2~3
  • EP3486873B1 patent drawingFigure 4

AI summary

A computer-implemented method of implant detection includes receiving a three-dimensional (3D) image of an anatomy portion of a patient from computed tomography (CT) projections of the patient in an image processing computing system. A cluster of voxels forming an implant candidate is identified on a CT slice of the 3D image and the identified implant candidate is compared with artifacts of implants from an implant database stored in a memory of the computing system. A best-fit implant is selected from the implant database and a graphical image of the best-fit implant is overlaid on the CT slice on a display of the computing system.