title: Ultrasound and magnetic resonance imaging in the evaluation of psoriatic dactylitis: status and perspectives.
abstract: OBJECTIVE
  Dactylitis, a characteristic feature of the spondyloarthropathies, occurs in up to 48% of patients with psoriatic arthritis (PsA). No clear consensus on the underlying components and pathogenesis of dactylitis exists in the literature. We undertook a systematic review of ultrasound (US) and magnetic resonance imaging (MRI) literature to better define imaging elements that contribute to the dactylitic digit seen in PsA. Our objectives were to determine first the level of homogeneity of each imaging modality's definition of the components of dactylitis, and second, to evaluate the metric properties of each imaging modality according to the Outcome Measures in Rheumatology Clinical Trials (OMERACT) filter.
  
  
  METHODS
  Searches were performed in PUBMED and EMBASE for articles pertaining to MRI, US, and dactylitis. Data regarding the reported features of dactylitis were collected and categorized, and the metrological qualities of the studies were assessed.
  
  
  RESULTS
  The most commonly described features of dactylitis were flexor tendon tenosynovitis and joint synovitis (90%). Extratendinous soft tissue thickening and extensor tendonitis were described nearly equally as being present and absent. Discrepancy exists as to whether entheses proper contribute to the etiology of dactylitis. An increasing number of studies categorize abnormalities in several tissue compartments including the soft tissue, tendon sheaths, and joints, as well as ligaments.
  
  
  CONCLUSIONS
  The understanding of which tissues contribute to dactylitic inflammation has evolved. However, there is a lack of literature regarding the natural history of these abnormalities. This systematic review provides guidance in defining elementary lesions that may discriminate dactylitic digits from normal digits, leading to development of a composite measure of activity and severity of dactylitis.
authors.affiliation: From the Division of Rheumatology, University of Florida College of Medicine, Jacksonville, Florida, USA.
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Bakewell
authors.forename: Ignazio
authors.initials: I
authors.lastname: Olivieri
authors.forename: Sibel Z
authors.initials: SZ
authors.lastname: Aydin
authors.forename: Christian
authors.initials: C
authors.lastname: Dejaco
authors.forename: Kei
authors.initials: K
authors.lastname: Ikeda
authors.forename: Marwin
authors.initials: M
authors.lastname: Gutierrez
authors.forename: Lene
authors.initials: L
authors.lastname: Terslev
authors.forename: Ralf
authors.initials: R
authors.lastname: Thiele
authors.forename: Maria Antionetta
authors.initials: MA
authors.lastname: D'Agostino
authors.forename: Gurjit S
authors.initials: GS
authors.lastname: Kaeley
mesh_terms: D015535:Arthritis, Psoriatic / Q000000981:diagnostic imaging* / Q000473:pathology*; D005384:Finger Joint / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D013585:Synovitis / Q000000981:diagnostic imaging / Q000473:pathology; D013717:Tenosynovitis / Q000000981:diagnostic imaging / Q000473:pathology; D014463:Ultrasonography / Q000379:methods*
keywords: DACTYLITIS; MAGNETIC RESONANCE IMAGING; PSORIASIS; PSORIATIC ARTHRITIS; ULTRASONOGRAPHY