Dual-energy computed tomography - How accurate is gemstone spectrum imaging metal artefact reduction: its application to orthopedic metal implants

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Objective: To assess the accuracy and suitability of dual-energy computed tomography (DECT) in scanningmetals used in orthopedic implants. Materials and Methods: Four metal phantoms (Cobalt Chrome, Titanium Grade 5, Stainless Steel 316, and Stainless Steel 630), commonly usedmaterials in orthopedic implants, were scanned by conventional, polychromatic CT as well as Gemstone Spectrum Imaging (GSI) DECT, with and without metal artefact reduction software (MARS). Scans were assessed for artefact based on Hounsfield unit values; and surfaces generated, based on a Canny edge detection algorithm. Two separate metal implants were also scanned and assessed for dimensional accuracy. Results: Conventional, polychromatic CT, and GSI DECT (without MARS) scans displayed major beam hardening in the presence of all four metals. The GSI DECTwith MARS showed very clear and reproducible boundaries with minimal noise surrounding the metal phantoms. However, geometric analysis found overestimation of the dimensions, volume, and surface area for most of the metal phantoms. Titanium displayed the least artefact, compared to the other metals, in all scan scenarios. Conclusions: Although metal artefact reduction using GSI DECT looks superior to conventional CT, when measured objectively, it was shown to overestimate geometries and skew dimensions. The GSI DECT with MARS should be used with caution, especially when assessing questions of implant shape or wear.

LanguageEnglish
Pages925-935
Number of pages11
JournalJournal of Computer Assisted Tomography
Volume39
Issue number6
DOIs
Publication statusPublished - 2015

Fingerprint

Artifacts
Orthopedics
Metals
Tomography
Software
Stainless Steel
Titanium
Cobalt
Noise

Cite this

@article{7ab71c78f96d46eeba43f1de6bc3b804,
title = "Dual-energy computed tomography - How accurate is gemstone spectrum imaging metal artefact reduction: its application to orthopedic metal implants",
abstract = "Objective: To assess the accuracy and suitability of dual-energy computed tomography (DECT) in scanningmetals used in orthopedic implants. Materials and Methods: Four metal phantoms (Cobalt Chrome, Titanium Grade 5, Stainless Steel 316, and Stainless Steel 630), commonly usedmaterials in orthopedic implants, were scanned by conventional, polychromatic CT as well as Gemstone Spectrum Imaging (GSI) DECT, with and without metal artefact reduction software (MARS). Scans were assessed for artefact based on Hounsfield unit values; and surfaces generated, based on a Canny edge detection algorithm. Two separate metal implants were also scanned and assessed for dimensional accuracy. Results: Conventional, polychromatic CT, and GSI DECT (without MARS) scans displayed major beam hardening in the presence of all four metals. The GSI DECTwith MARS showed very clear and reproducible boundaries with minimal noise surrounding the metal phantoms. However, geometric analysis found overestimation of the dimensions, volume, and surface area for most of the metal phantoms. Titanium displayed the least artefact, compared to the other metals, in all scan scenarios. Conclusions: Although metal artefact reduction using GSI DECT looks superior to conventional CT, when measured objectively, it was shown to overestimate geometries and skew dimensions. The GSI DECT with MARS should be used with caution, especially when assessing questions of implant shape or wear.",
author = "Dan{\`e} Dabirrahmani and John Magnussen and Appleyard, {Richard Charles}",
year = "2015",
doi = "10.1097/RCT.0000000000000300",
language = "English",
volume = "39",
pages = "925--935",
journal = "Journal of Computer Assisted Tomography",
issn = "0363-8715",
publisher = "Lippincott Williams and Wilkins",
number = "6",

}

TY - JOUR

T1 - Dual-energy computed tomography - How accurate is gemstone spectrum imaging metal artefact reduction

T2 - Journal of Computer Assisted Tomography

AU - Dabirrahmani, Danè

AU - Magnussen, John

AU - Appleyard, Richard Charles

PY - 2015

Y1 - 2015

N2 - Objective: To assess the accuracy and suitability of dual-energy computed tomography (DECT) in scanningmetals used in orthopedic implants. Materials and Methods: Four metal phantoms (Cobalt Chrome, Titanium Grade 5, Stainless Steel 316, and Stainless Steel 630), commonly usedmaterials in orthopedic implants, were scanned by conventional, polychromatic CT as well as Gemstone Spectrum Imaging (GSI) DECT, with and without metal artefact reduction software (MARS). Scans were assessed for artefact based on Hounsfield unit values; and surfaces generated, based on a Canny edge detection algorithm. Two separate metal implants were also scanned and assessed for dimensional accuracy. Results: Conventional, polychromatic CT, and GSI DECT (without MARS) scans displayed major beam hardening in the presence of all four metals. The GSI DECTwith MARS showed very clear and reproducible boundaries with minimal noise surrounding the metal phantoms. However, geometric analysis found overestimation of the dimensions, volume, and surface area for most of the metal phantoms. Titanium displayed the least artefact, compared to the other metals, in all scan scenarios. Conclusions: Although metal artefact reduction using GSI DECT looks superior to conventional CT, when measured objectively, it was shown to overestimate geometries and skew dimensions. The GSI DECT with MARS should be used with caution, especially when assessing questions of implant shape or wear.

AB - Objective: To assess the accuracy and suitability of dual-energy computed tomography (DECT) in scanningmetals used in orthopedic implants. Materials and Methods: Four metal phantoms (Cobalt Chrome, Titanium Grade 5, Stainless Steel 316, and Stainless Steel 630), commonly usedmaterials in orthopedic implants, were scanned by conventional, polychromatic CT as well as Gemstone Spectrum Imaging (GSI) DECT, with and without metal artefact reduction software (MARS). Scans were assessed for artefact based on Hounsfield unit values; and surfaces generated, based on a Canny edge detection algorithm. Two separate metal implants were also scanned and assessed for dimensional accuracy. Results: Conventional, polychromatic CT, and GSI DECT (without MARS) scans displayed major beam hardening in the presence of all four metals. The GSI DECTwith MARS showed very clear and reproducible boundaries with minimal noise surrounding the metal phantoms. However, geometric analysis found overestimation of the dimensions, volume, and surface area for most of the metal phantoms. Titanium displayed the least artefact, compared to the other metals, in all scan scenarios. Conclusions: Although metal artefact reduction using GSI DECT looks superior to conventional CT, when measured objectively, it was shown to overestimate geometries and skew dimensions. The GSI DECT with MARS should be used with caution, especially when assessing questions of implant shape or wear.

UR - http://www.scopus.com/inward/record.url?scp=84947611574&partnerID=8YFLogxK

U2 - 10.1097/RCT.0000000000000300

DO - 10.1097/RCT.0000000000000300

M3 - Article

VL - 39

SP - 925

EP - 935

JO - Journal of Computer Assisted Tomography

JF - Journal of Computer Assisted Tomography

SN - 0363-8715

IS - 6

ER -