title: A Clinical and Experimental Comparison of Time of Flight PET/MRI and PET/CT Systems.
abstract: OBJECTIVE
  The purpose of the study was to compare image quality and quantitative accuracy of positron emission tomography/magnetic resonance imaging (PET/MRI) and PET/computed tomography (PET/CT) systems with time of flight PET gantries, using phantom and clinical studies.
  
  
  METHODS
  Identical phantom experiments were performed on both systems. Calibration, uniformity, and standardized uptake value (SUV) recovery were measured. A clinical PET/CT versus PET/MRI comparison was performed using [(18)F]fluoromethylcholine ([(18)F]FCH).
  
  
  RESULTS
  Calibration accuracy and image uniformity were comparable between systems. SUV recovery met EANM/EARL requirements on both scanners. Thirty-four lesions with comparable PET image quality were identified. Lesional SUVmax differences of 4 ± 26% between PET/MRI and PET/CT data were observed (R (2) = 0.79, slope = 1.02). In healthy tissues, PET/MRI-derived SUVs were 16 ± 11% lower than on PET/CT (R (2) = 0.98, slope = 0.86).
  
  
  CONCLUSIONS
  PET/MRI and PET/CT showed comparable performance with respect to calibration accuracy, image uniformity, and SUV recovery. [(18)F]FCH uptake values for both healthy tissues and lesions corresponded reasonably well between MR- and CT-based systems, but only in regions free of MR-based attenuation artifacts.
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, PO Box 7057, 1007, MB, Amsterdam, The Netherlands. d.oprea-lager@vumc.nl.
authors.forename: Daniela E
authors.initials: DE
authors.lastname: Oprea-Lager
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, PO Box 7057, 1007, MB, Amsterdam, The Netherlands.
authors.forename: Maqsood
authors.initials: M
authors.lastname: Yaqub
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, PO Box 7057, 1007, MB, Amsterdam, The Netherlands.
authors.forename: Indra C
authors.initials: IC
authors.lastname: Pieters
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, PO Box 7057, 1007, MB, Amsterdam, The Netherlands.
authors.forename: Rinze
authors.initials: R
authors.lastname: Reinhard
authors.affiliation: Department of Urology, VU University Medical Center, PO Box 7057, 1007, MB, Amsterdam, The Netherlands.
authors.forename: Reindert J A
authors.initials: RJ
authors.lastname: van Moorselaar
authors.affiliation: Department of Medical Oncology, VU University Medical Center, PO Box 7057, 1007, MB, Amsterdam, The Netherlands.
authors.forename: Alfons J M
authors.initials: AJ
authors.lastname: van den Eertwegh
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, PO Box 7057, 1007, MB, Amsterdam, The Netherlands.
authors.forename: Otto S
authors.initials: OS
authors.lastname: Hoekstra
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, PO Box 7057, 1007, MB, Amsterdam, The Netherlands.
authors.forename: Adriaan A
authors.initials: AA
authors.lastname: Lammertsma
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, PO Box 7057, 1007, MB, Amsterdam, The Netherlands.
authors.forename: Ronald
authors.initials: R
authors.lastname: Boellaard
mesh_terms: D000368:Aged; D000465:Algorithms; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography / Q000379:methods*; D011467:Prostate / Q000000981:diagnostic imaging; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Multimodality imaging; PET/CT; PET/MRI; Prostate cancer; [18F]fluoromethylcholine