title: Interobserver agreement on cortical tracer transit in 99mTc-MAG3 renography applied to congenital hydronephrosis.
abstract: OBJECTIVE
  This study aims to evaluate interobserver agreement on visual analysis of technetium-99m mercaptoacetyltriglycine (Tc-MAG3) renal tissue transit used for the evaluation of antenatal hydronephrosis.
  
  
  METHODS
  Thirty-eight Tc-MAG3 diuretic renograms were retrospectively collected between 1 and 31 December 2015. The 1-min reframed images were presented to four nuclear medicine consultants and to two nuclear medicine residents, one in the first year of the training program and the others in their fourth and final year. These observers were asked to classify the radiotracer cortical transit (normal/delayed) based solely on visual assessment of the images. For the interobserver agreement, modified Fleiss' kappa (κ) analysis for multiple raters was carried out. For both groups, percentages of agreement were also calculated.
  
  
  RESULTS
  A total of 69 kidneys were evaluated. All four nuclear medicine consultants agreed on the classification of 88.4% of the kidneys. When the agreement of at least three of the four observers was considered, the percentage of agreement reached 98.6%. The two nuclear medicine residents agreed on the classification of 69.6% of the kidneys. The modified Fleiss' κ-value was 0.88 (95% confidence interval: 0.79-0.95) for the group of nuclear medicine consultants, indicating almost perfect agreement. For the residents, it was 0.39 (95% confidence interval: 0.16-0.59), suggesting fair agreement.
  
  
  CONCLUSIONS
  Our results seem to indicate that there is an almost perfect agreement in the qualitative identification of delayed cortical transit among physicians with experience at observing renographic images.
authors.affiliation: aNuclear Medicine Service, Garcia de Orta Hospital, E.P.E., Almada bNuclear Medicine Service, Francisco Gentil Portuguese Institute of Oncology from Porto, E.P.E. cEpidemiology and Statistics Research Unit, Central Lisbon Hospital Center, E.P.E. dNOVA Medical School FCM, Universidade Nova de Lisboa, Lisbon, Portugal eRadioisotopes Department, St Pierre University Hospital, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Santos
authors.forename: Liliana
authors.initials: L
authors.lastname: Violante
authors.forename: Susana
authors.initials: S
authors.lastname: Carmona
authors.forename: Ana
authors.initials: A
authors.lastname: Prata
authors.forename: Margarida
authors.initials: M
authors.lastname: Rodrigues Victor
authors.forename: Joaquim G
authors.initials: JG
authors.lastname: Santos
authors.forename: Joaquim
authors.initials: J
authors.lastname: Araújo Sequeira
authors.forename: Marta
authors.initials: M
authors.lastname: Alves
authors.forename: Ana Luísa
authors.initials: AL
authors.lastname: Papoila
authors.forename: Amy
authors.initials: A
authors.lastname: Piepsz
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D006801:Humans; D006869:Hydronephrosis / Q000151:congenital* / Q000000981:diagnostic imaging* / Q000378:metabolism; D007223:Infant; D007231:Infant, Newborn; D007668:Kidney / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000378:metabolism; D007672:Kidney Cortex / Q000000981:diagnostic imaging / Q000378:metabolism; D015588:Observer Variation; D011866:Radioisotope Renography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012189:Retrospective Studies; D017263:Technetium Tc 99m Mertiatide / Q000493:pharmacokinetics
chemical_list: D019275:Radiopharmaceuticals; D017263:Technetium Tc 99m Mertiatide