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Hybrid PET/MRI: An algorithm to reduce metal artifacts from dental implants in dixon-based attenuation map generation using a mavric sequence


Burger, Irene A; Wurnig, Moritz C; Becker, Anton; Kenkel, David; Gaspar, Delso; Veit-Haibach, Patrick; Boss, Andreas (2015). Hybrid PET/MRI: An algorithm to reduce metal artifacts from dental implants in dixon-based attenuation map generation using a mavric sequence. Journal of Nuclear Medicine, 56(1):93-97.

Abstract

It was the aim of this study to implement an algorithm, modifing Dixon-based magnetic resonance imaging (MRI) datasets for attenuation correction in hybrid PET/MRI with a Multi-Acquisition Variable Resonance Image Combination (MAVRIC) sequence to reduce metal artifacts.
METHODS: After ethics approval, in eight oncological patients with dental implants data were acquired in a trimodality setup with PET/CT and MRI. The protocol included a whole-body 3D dual gradient-echo sequence (Dixon) used for MRI based PET attenuation correction (AC), and a high resolution MAVRIC sequence, applied in the oral area compromised by dental implants. An algorithm was implemented correcting the Dixon-based µMaps by using the MAVRIC in areas of Dixon signal voids. Artifact size of the corrected µMaps was compared to the uncorrected MRI µMaps.
RESULTS: The algorithm was robust in all patients. There was a significant reduction in mean artifact size of 70.5% between uncorrected and corrected µMaps from 697±589mm(2) to 202±119mm(2) (P = 0.016).
CONCLUSION: The proposed algorithm could improve MRI based attenuation correction in critical areas, when standard AC is hampered by metal artifacts, using a MAVRIC.

It was the aim of this study to implement an algorithm, modifing Dixon-based magnetic resonance imaging (MRI) datasets for attenuation correction in hybrid PET/MRI with a Multi-Acquisition Variable Resonance Image Combination (MAVRIC) sequence to reduce metal artifacts.
METHODS: After ethics approval, in eight oncological patients with dental implants data were acquired in a trimodality setup with PET/CT and MRI. The protocol included a whole-body 3D dual gradient-echo sequence (Dixon) used for MRI based PET attenuation correction (AC), and a high resolution MAVRIC sequence, applied in the oral area compromised by dental implants. An algorithm was implemented correcting the Dixon-based µMaps by using the MAVRIC in areas of Dixon signal voids. Artifact size of the corrected µMaps was compared to the uncorrected MRI µMaps.
RESULTS: The algorithm was robust in all patients. There was a significant reduction in mean artifact size of 70.5% between uncorrected and corrected µMaps from 697±589mm(2) to 202±119mm(2) (P = 0.016).
CONCLUSION: The proposed algorithm could improve MRI based attenuation correction in critical areas, when standard AC is hampered by metal artifacts, using a MAVRIC.

Citations

6 citations in Web of Science®
6 citations in Scopus®
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Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > University Hospital Zurich > Clinic for Diagnostic and Interventional Radiology
04 Faculty of Medicine > University Hospital Zurich > Clinic for Nuclear Medicine
Dewey Decimal Classification:610 Medicine & health
Language:English
Date:2015
Deposited On:30 Dec 2014 10:32
Last Modified:05 Apr 2016 18:41
Publisher:Society of Nuclear Medicine
ISSN:0161-5505
Free access at:Publisher DOI. An embargo period may apply.
Publisher DOI:https://doi.org/10.2967/jnumed.114.145862
PubMed ID:25500830

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