title: Consensus-based identification of factors related to false-positives in ultrasound scanning of synovitis and tenosynovitis.
abstract: BACKGROUND
  We aimed to identify causes of false-positives in ultrasound scanning of synovial/tenosynovial/bursal inflammation and provide corresponding imaging examples.
  
  
  METHODS
  We first performed systematic literature review to identify previously reported causes of false-positives. We next determined causes of false-positives and corresponding example images for educational material through Delphi exercises and discussion by 15 experts who were an instructor and/or a lecturer in the 2013 advanced course for musculoskeletal ultrasound organized by Japan College of Rheumatology Committee for the Standardization of Musculoskeletal Ultrasonography.
  
  
  RESULTS
  Systematic literature review identified 11 articles relevant to sonographic false-positives of synovial/tenosynovial inflammation. Based on these studies, 21 candidate causes of false-positives were identified in the consensus meeting. Of these items, 11 achieved a predefined consensus (≥ 80%) in Delphi exercise and were classified as follows: (I) Gray-scale assessment [(A) non-specific synovial findings and (B) normal anatomical structures which can mimic synovial lesions due to either their low echogenicity or anisotropy]; (II) Doppler assessment [(A) Intra-articular normal vessels and (B) reverberation)]. Twenty-four corresponding examples with 49 still and 23 video images also achieved consensus.
  
  
  CONCLUSIONS
  Our study provides a set of representative images that can help sonographers to understand false-positives in ultrasound scanning of synovitis and tenosynovitis.
authors.affiliation: a Department of Allergy and Clinical Immunology , Chiba University Hospital , Chiba , Japan .
authors.forename: Kei
authors.initials: K
authors.lastname: Ikeda
authors.affiliation: b Hokkaido Medical Center for Rheumatic Diseases , Sapporo , Japan .
authors.forename: Akihiro
authors.initials: A
authors.lastname: Narita
authors.affiliation: c Department of Internal Medicine and Rheumatology , Juntendo University Faculty of Medicine , Tokyo , Japan .
authors.forename: Michihiro
authors.initials: M
authors.lastname: Ogasawara
authors.affiliation: d Center for Rheumatic Diseases, Yokohama City University Medical Center , Yokohama , Japan .
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ohno
authors.affiliation: e Department of Inflammation and Immunology , Kyoto Prefectural University of Medicine , Kyoto , Japan .
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kawahito
authors.affiliation: f Unit of Translational Medicine, Department of Immunology and Rheumatology , Nagasaki University Graduate School of Biomedical Sciences , Nagasaki , Japan .
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kawakami
authors.affiliation: g Department of Orthopaedic Surgery , Kyoto University Graduate School of Medicine , Kyoto , Japan .
authors.forename: Hiromu
authors.initials: H
authors.lastname: Ito
authors.affiliation: h Department of Orthopaedic Surgery , University of Toyama , Toyama , Japan .
authors.forename: Isao
authors.initials: I
authors.lastname: Matsushita
authors.affiliation: i Division of Allergy and Rheumatology , Japanese Red Cross Medical Center , Tokyo , Japan .
authors.forename: Takeshi
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: j Department of Endocrinology and Rheumatology , Kurashiki Central Hospital , Kurashiki , Okayama , Japan .
authors.forename: Kenta
authors.initials: K
authors.lastname: Misaki
authors.affiliation: k Division of Rheumatology , Toho University Ohashi Medical Center , Tokyo , Japan .
authors.forename: Takehisa
authors.initials: T
authors.lastname: Ogura
authors.affiliation: l Faculty of Health Sciences, Hokkaido University , Sapporo , Japan .
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Kamishima
authors.affiliation: m Department of Rheumatology , Tokyo Women's Medical University Yachiyo Medical Center , Yachiyo , Chiba , Japan .
authors.forename: Yohei
authors.initials: Y
authors.lastname: Seto
authors.affiliation: n Department of Human Morphology , Science of Functional Recovery and Reconstruction, Okayama University Graduate School of Medicine , Okayama , Japan .
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Nakahara
authors.affiliation: o Department of Orthopaedic Surgery and Rheumatology , Nagoya Medical Center, National Hospital Organization , Nagoya , Japan .
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kaneko
authors.affiliation: a Department of Allergy and Clinical Immunology , Chiba University Hospital , Chiba , Japan .
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: b Hokkaido Medical Center for Rheumatic Diseases , Sapporo , Japan .
authors.forename: Mihoko
authors.initials: M
authors.lastname: Henmi
authors.affiliation: b Hokkaido Medical Center for Rheumatic Diseases , Sapporo , Japan .
authors.forename: Jun
authors.initials: J
authors.lastname: Fukae
authors.affiliation: n Department of Human Morphology , Science of Functional Recovery and Reconstruction, Okayama University Graduate School of Medicine , Okayama , Japan .
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Nishida
authors.affiliation: p Department of Internal Medicine , Faculty of Medicine, University of Tsukuba , Tsukuba , Japan , and.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Sumida
authors.affiliation: q NTT Sapporo Medical Center , Sapporo , Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Koike
mesh_terms: D032921:Consensus; D003697:Delphi Technique; D005189:False Positive Reactions; D006801:Humans; D007564:Japan; D012219:Rheumatology / Q000592:standards*; D013583:Synovial Membrane / Q000000981:diagnostic imaging*; D013585:Synovitis / Q000000981:diagnostic imaging*; D013717:Tenosynovitis / Q000000981:diagnostic imaging*; D014463:Ultrasonography
keywords: False-positive; Pitfall; Synovitis; Tenosynovitis; Ultrasound