Verena Ruhlmann1, Philipp Heusch2, Hilmar Kühl3, Karsten Beiderwellen3, Gerald Antoch2, Michael Forsting3, Andreas Bockisch4, Christian Buchbender2, Harald H Quick5,6. 1. Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany. verena.ruhlmann@uk-essen.de. 2. Department of Diagnostic and Interventional Radiology, Medical Faculty, University of Dusseldorf, 40225, Dusseldorf, Germany. 3. Department of Diagnostic and Interventional Radiology and Neuroradiology, University of Duisburg-Essen, 45147, Essen, Germany. 4. Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany. 5. Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, 45141, Essen, Germany. 6. High Field and Hybrid MR Imaging, University Hospital Essen, 45147, Essen, Germany.
Abstract
OBJECTIVE: To evaluate the influence of Gadolinium contrast agent on image segmentation in magnetic resonance (MR)-based attenuation correction (AC) with four-segment dual-echo time Dixon-sequences in whole-body [18F]-fluorodeoxyglucose positron emission tomography (PET)/MR imaging, and to analyze the consecutive effect on standardized uptake value (SUV). MATERIALS AND METHODS: Hybrid imaging with an integrated PET/MR system was performed in 30 oncological patients. AC was based on MR imaging with a Dixon sequence with subsequent automated image segmentation. AC maps (µmaps) were acquired and reconstructed prior to (µmap-gd) and after (µmap+gd) Gd-contrast agent application. For quantification purposes, the SUV of organs and tumors based on both µmaps were compared. RESULTS: Tissue classification based on µmap-gd was correct in 29/30 patients; based on µmap+gd, the brain was falsely classified as fat in 12/30 patients with significant underestimation of SUV. In all cancerous lesions, tissue segmentation was correct. All concordant µmaps-gd/+gd resulted in no significant difference in SUV. CONCLUSION: In PET/MR, Gd-contrast agent potentially influences fat/water separation in Dixon-sequences of the head with above-average false tissue segmentation and an associated underestimation of SUV. Thus, MR-based AC should be acquired prior to Gd-contrast agent application. Additionally, integrating the MR-based AC maps into the reading-routine in PET/MR is recommended to avoid interpretation errors in cases where tissue segmentation fails.
OBJECTIVE: To evaluate the influence of Gadolinium contrast agent on image segmentation in magnetic resonance (MR)-based attenuation correction (AC) with four-segment dual-echo time Dixon-sequences in whole-body [18F]-fluorodeoxyglucose positron emission tomography (PET)/MR imaging, and to analyze the consecutive effect on standardized uptake value (SUV). MATERIALS AND METHODS: Hybrid imaging with an integrated PET/MR system was performed in 30 oncological patients. AC was based on MR imaging with a Dixon sequence with subsequent automated image segmentation. AC maps (µmaps) were acquired and reconstructed prior to (µmap-gd) and after (µmap+gd) Gd-contrast agent application. For quantification purposes, the SUV of organs and tumors based on both µmaps were compared. RESULTS: Tissue classification based on µmap-gd was correct in 29/30 patients; based on µmap+gd, the brain was falsely classified as fat in 12/30 patients with significant underestimation of SUV. In all cancerous lesions, tissue segmentation was correct. All concordant µmaps-gd/+gd resulted in no significant difference in SUV. CONCLUSION: In PET/MR, Gd-contrast agent potentially influences fat/water separation in Dixon-sequences of the head with above-average false tissue segmentation and an associated underestimation of SUV. Thus, MR-based AC should be acquired prior to Gd-contrast agent application. Additionally, integrating the MR-based AC maps into the reading-routine in PET/MR is recommended to avoid interpretation errors in cases where tissue segmentation fails.
Entities:
Keywords:
Attenuation correction (AC); MR-based tissue segmentation; PET/MR; SUV
Authors: Sune H Keller; Søren Holm; Adam E Hansen; Bernhard Sattler; Flemming Andersen; Thomas L Klausen; Liselotte Højgaard; Andreas Kjær; Thomas Beyer Journal: MAGMA Date: 2012-09-21 Impact factor: 2.310
Authors: Vincent Keereman; Yves Fierens; Tom Broux; Yves De Deene; Max Lonneux; Stefaan Vandenberghe Journal: J Nucl Med Date: 2010-05 Impact factor: 10.057
Authors: Daniel H Paulus; Harald H Quick; Christian Geppert; Matthias Fenchel; Yiqiang Zhan; Gerardo Hermosillo; David Faul; Fernando Boada; Kent P Friedman; Thomas Koesters Journal: J Nucl Med Date: 2015-05-29 Impact factor: 10.057
Authors: N M Rofsky; V S Lee; G Laub; M A Pollack; G A Krinsky; D Thomasson; M M Ambrosino; J C Weinreb Journal: Radiology Date: 1999-09 Impact factor: 11.105
Authors: Axel Martinez-Möller; Michael Souvatzoglou; Gaspar Delso; Ralph A Bundschuh; Christophe Chefd'hotel; Sibylle I Ziegler; Nassir Navab; Markus Schwaiger; Stephan G Nekolla Journal: J Nucl Med Date: 2009-03-16 Impact factor: 10.057
Authors: Philipp Heusch; Christian Buchbender; Karsten Beiderwellen; Felix Nensa; Verena Hartung-Knemeyer; Thomas C Lauenstein; Andreas Bockisch; Michael Forsting; Gerald Antoch; Till A Heusner Journal: Eur J Radiol Date: 2013-02-08 Impact factor: 3.528