title: Reproducibility and repeatability of same-day two sequential FDG PET/MR and PET/CT.
abstract: BACKGROUND
  To determine PET/CT and PET/MR reproducibility and PET/MR repeatability of fluorine 18 fluorodeoxyglucose (FDG) uptake measurements in tumors in cancer patients.
  
  
  METHODS
  This IRB approved prospective study was performed between October 2015 and February 2016 in consecutive patients who performed same day PET/CT and two sequential PET/MR. Thirty three patients with visible tumors (N = 63) were included. SUV for body weight (SUV) and lean body mass (SUL) were obtained. Volume of interest (VOI) with a threshold of 40% was used and SUV/L's, metabolic tumor volume (MTV) and tumor to liver ratio (T/L) were calculated. Measurements were plotted in a scattered diagram to visually identify correlation, a regression line was drawn and the equation of the line was calculated. Bland-Altman plots expressed as percentages were constructed to assess the agreement between measurements. The maximal clinically acceptable limits range was defined as ±30%.
  
  
  RESULTS
  Lesional SUV's, SUL's and MTV corrected to body weight (BW) and lean body mass (LBM) demonstrated strong positive linear correlation between PET/CT and PET/MR and between two sequential PET/MR. The 95% limits of agreement ranged from -27.7 to 17.5 with a mean of -5.1 and -27.6 to 17.9 with a mean of -4.9 for SUVpeak and SULpeak, respectively for sequential PET/MR. Other PET metrics demonstrated limits range that is above ±30% between PET/CT and PET/MR and between two sequential PET/MR.
  
  
  CONCLUSIONS
  PET/MR SUV/L peak has a clinically acceptable repeatability performance and can be used to evaluate the response to treatment.
authors.affiliation: Department of Nuclear Medicine, Assuta Medical Center, 20 habarzel st., 6971028, Tel-Aviv, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel-Aviv, Israel.
authors.forename: David
authors.initials: D
authors.lastname: Groshar
authors.affiliation: Department of Nuclear Medicine, Assuta Medical Center, 20 habarzel st., 6971028, Tel-Aviv, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel-Aviv, Israel.
authors.forename: Hanna
authors.initials: H
authors.lastname: Bernstine
authors.affiliation: Department of Nuclear Medicine, Assuta Medical Center, 20 habarzel st., 6971028, Tel-Aviv, Israel.
authors.forename: Natalia
authors.initials: N
authors.lastname: Goldberg
authors.affiliation: Department of Nuclear Medicine, Assuta Medical Center, 20 habarzel st., 6971028, Tel-Aviv, Israel.
authors.forename: Meital
authors.initials: M
authors.lastname: Nidam
authors.affiliation: Department of Nuclear Medicine, Assuta Medical Center, 20 habarzel st., 6971028, Tel-Aviv, Israel.
authors.forename: Dan
authors.initials: D
authors.lastname: Stein
authors.affiliation: Department of Nuclear Medicine, Assuta Medical Center, 20 habarzel st., 6971028, Tel-Aviv, Israel.
authors.forename: Ifat
authors.initials: I
authors.lastname: Abadi-Korek
authors.affiliation: Department of Nuclear Medicine, Assuta Medical Center, 20 habarzel st., 6971028, Tel-Aviv, Israel. liranura@gmail.com.
authors.forename: Liran
authors.initials: L
authors.lastname: Domachevsky
mesh_terms: D000328:Adult; D000368:Aged; 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 / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D047368:Tumor Burden
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: PET/MR; Reliability; Repeatability; Reproducibility; SUV