title: Simultaneous carotid PET/MR: feasibility and improvement of magnetic resonance-based attenuation correction.
abstract: Errors in quantification of carotid positron emission tomography (PET) in simultaneous PET/magnetic resonance (PET/MR) imaging when not incorporating bone in MR-based attenuation correction (MRAC) maps, and possible solutions, remain to be fully explored. In this study, we demonstrated techniques to improve carotid vascular PET/MR quantification by adding a bone tissue compartment to MRAC maps and deriving continuous Dixon-based MRAC (MRACCD) maps. We demonstrated the feasibility of applying ultrashort echo time-based bone segmentation and generation of continuous Dixon MRAC to improve PET quantification on five subjects. We examined four different MRAC maps: system standard PET/MR MRAC map (air, lung, fat, soft tissue) (MRACPET/MR), standard PET/MR MRAC map with bone (air, lung, fat, soft tissue, bone) (MRACPET/MRUTE), MRACCD map (no bone) and continuous Dixon-based MRAC map with bone (MRACCDUTE). The same PET emission data was then reconstructed with each respective MRAC map and a CTAC map (PETPET/MR, PETPET/MRUTE, PETCD, PECDUTE) to assess effects of the different attenuation maps on PET quantification in the carotid arteries and neighboring tissues. Quantitative comparison of MRAC attenuation values for each method compared to CTAC showed small differences in the carotid arteries with UTE-based segmentation of bone included and/or continuous Dixon MRAC; however, there was very good correlation for all methods in the voxel-by-voxel comparison. ROI-based analysis showed a similar trend in the carotid arteries with the lowest correlation to PETCTAC being PETPETMR and the highest correlation to PETCTAC being PETCDUTE. We have demonstrated the feasibility of applying UTE-based segmentation and continuous Dixon MRAC maps to improve carotid PET/MR vascular quantification.
authors.affiliation: Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, P. O. Box 1234, New York, NY, 10029, USA.|Department of Biomedical Engineering, The City College of New York, New York, NY, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Bini
authors.affiliation: Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, P. O. Box 1234, New York, NY, 10029, USA.|Department of Biomedical Engineering, The City College of New York, New York, NY, USA.
authors.forename: Mootaz
authors.initials: M
authors.lastname: Eldib
authors.affiliation: Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, P. O. Box 1234, New York, NY, 10029, USA.|Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: Philip M
authors.initials: PM
authors.lastname: Robson
authors.affiliation: Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, P. O. Box 1234, New York, NY, 10029, USA.|Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: Claudia
authors.initials: C
authors.lastname: Calcagno
authors.affiliation: Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, P. O. Box 1234, New York, NY, 10029, USA. zahi.fayad@mssm.edu.|Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA. zahi.fayad@mssm.edu.|Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josée and Henry R. Kravis Cardiovascular Health Center, Icahn School of Medicine at Mount Sinai, New York, NY, USA. zahi.fayad@mssm.edu.
authors.forename: Zahi A
authors.initials: ZA
authors.lastname: Fayad
mesh_terms: D000465:Algorithms; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000473:pathology*; D002340:Carotid Artery Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D005240:Feasibility Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D018810:Magnetic Resonance Angiography; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013131:Spine / Q000000981:diagnostic imaging / Q000473:pathology
keywords: Attenuation correction; Carotid arteries; Dixon; PET/MR; Ultrashort echo time