title: Conspicuity of Malignant Lesions on PET/CT and Simultaneous Time-Of-Flight PET/MRI.
abstract: To compare the conspicuity of malignant lesions between FDG PET/CT and a new simultaneous, time-of-flight (TOF) enabled PET/MRI scanner.
  
  
  
  All patients underwent a single-injection of FDG, followed by a dual imaging protocol consisting of PET/CT followed by TOF PET/MRI. PET/CT and PET/MRI images were evaluated by two readers independently for areas of FDG uptake compatible with malignancy, and then categorized into 5 groups (1: PET/MRI and PET/CT positive; 2: PET/MRI positive, PET/CT positive in retrospect; 3: PET/CT positive, PET/MRI positive in retrospect; 4: PET/MRI positive, PET/CT negative; 5: PET/MRI negative, PET/CT positive) by consensus. Patients with no lesions on either study or greater than 10 lesions based on either modality were excluded from the study.
  
  
  
  Fifty-two patients (mean±SD age: 58±14 years) underwent the dual imaging protocol; of these, 29 patients with a total of 93 FDG-avid lesions met the inclusion criteria. The majority of lesions (56%) were recorded prospectively in the same location on PET/CT and PET/MRI. About an equal small fraction of lesions were seen on PET/CT but only retrospectively on PET/MRI (9%) and vice versa (12%). More lesions were identified only on PET/MRI but not on PET/CT, even in retrospect (96% vs. 81%, respectively; p = 0.003). Discrepant lesions had lower maximum standardized uptake value (SUVmax) than concordant lesions on both modalities (p<0.001).
  
  
  
  While most lesions were identified prospectively on both modalities, significantly more lesions were identified with PET/MRI than with PET/CT.
authors.affiliation: Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Stanford University, Stanford, California, United States of America.|Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California, United States of America.
authors.forename: Ryogo
authors.initials: R
authors.lastname: Minamimoto
authors.affiliation: Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Stanford University, Stanford, California, United States of America.|Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California, United States of America.
authors.forename: Andrei
authors.initials: A
authors.lastname: Iagaru
authors.affiliation: Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Stanford University, Stanford, California, United States of America.|Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California, United States of America.
authors.forename: Mehran
authors.initials: M
authors.lastname: Jamali
authors.affiliation: Department of Radiology, Stanford University, Stanford, California, United States of America.
authors.forename: Dawn
authors.initials: D
authors.lastname: Holley
authors.affiliation: Department of Radiology, Division of Nuclear Medicine and Molecular Imaging, Stanford University, Stanford, California, United States of America.
authors.forename: Amir
authors.initials: A
authors.lastname: Barkhodari
authors.affiliation: Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California, United States of America.|Department of Radiology, Stanford University, Stanford, California, United States of America.
authors.forename: Shreyas
authors.initials: S
authors.lastname: Vasanawala
authors.affiliation: Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California, United States of America.|Department of Radiology, Stanford University, Stanford, California, United States of America.
authors.forename: Greg
authors.initials: G
authors.lastname: Zaharchuk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003951:Diagnostic Errors; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D009369:Neoplasms / Q000000981:diagnostic imaging*; D000072078:Positron Emission Tomography Computed Tomography; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012189:Retrospective Studies
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18