RT Journal Article SR Electronic T1 A Path to Qualification of PET/MR Scanners for Multicenter Brain Imaging Studies: Evaluation of MR-based Attenuation Correction Methods Using a Patient Phantom JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP jnumed.120.261881 DO 10.2967/jnumed.120.261881 A1 Ciprian Catana A1 Richard Laforest A1 Hongyu An A1 Fernando Boada A1 Tuoyu Cao A1 David Faul A1 Bjoern Jakoby A1 Floris P Jansen A1 Brad J Kemp A1 Paul E. Kinahan A1 Peder E. Z. Larson A1 Michael A Levine A1 Piotr Maniawski A1 Osama Mawlawi A1 Jonathan McConathy A1 Alan McMillan A1 Julie C. Price A1 Abhejit Rajagopal A1 John Sunderland A1 Patrick Veit-Haibach A1 Kristen A Wangerin A1 Chunwei Ying A1 Thomas A. Hope YR 2021 UL http://jnm.snmjournals.org/content/early/2021/07/22/jnumed.120.261881.abstract AB Positron emission tomography and magnetic resonance imaging (PET/MRI) scanners cannot be qualified in the manner adopted for hybrid PET and computed tomography (CT) devices. The main hurdle with qualification in PET/MRI is that attenuation correction (AC) cannot be adequately measured in conventional PET phantoms due to the difficulty in converting the MRI images of the physical structures (e.g., plastic) into electron density maps. Over the last decade, a plethora of novel MR-based algorithms have been developed to more accurately derive the attenuation properties of the human head, including the skull. Although very promising, none of these techniques has yet emerged as an optimal and universally adopted strategy for AC in PET/MRI. In this work, we propose a path for PET/MRI qualification for multicenter brain imaging studies. Specifically, our solution is to separate the head attenuation correction from the other factors that affect PET data quantification and use a patient as a phantom to assess the former. The emission data collected on the integrated PET/MRI scanner to be qualified should be reconstructed using both MR- and CT-based AC methods and whole-brain qualitative and quantitative (both voxel-wise and regional) analyses should be performed. The MR-based approach will be considered satisfactory if the PET quantification bias is within the acceptance criteria specified herein. We have implemented this approach successfully across two PET/MRI scanner manufacturers at two sites.