title: "Crystal clear"-sonographic assessment of gout and calcium pyrophosphate deposition disease.
abstract: OBJECTIVE
  To date, high-resolution ultrasound (US) has not been fully exploited in the field of crystalline arthropathy. Both gout and calcium pyrophosphate deposition (CPPD) disease are significant diseases within the purview of the rheumatologist. The aim of this pictorial review was to present the principal findings in patients with crystal deposition in gout and CPPD.
  
  
  METHODS
  US pictures were obtained from 60 consecutive patients, 34 with CPPD disease and 26 with gout, whose diagnosis was confirmed by synovial fluid analysis. The US examinations were performed using the following US systems: Diasus (Dynamic Imaging, Livingstone, UK) and Logiq 9 (General Electric Medical Systems, Milwaukee, WI).
  
  
  RESULTS
  Pictorial evidence of the principal US findings in gout includes monosodium urate (MSU) deposition on the surface of articular cartilage, various patterns within synovial fluid ranging from completely anechoic fluid to collections filled with aggregates of variable shape and echogenicity, microdeposition within tendons, and tophus formation. In CPPD, the hallmark US features include crystal deposition within articular cartilage, calcification of fibrocartilage, together with focal crystal deposition within tendons.
  
  
  CONCLUSIONS
  US is an impressive imaging modality in crystalline arthropathy. The anatomical location of the crystal deposits, clearly depictable by US, allows differentiation between MSU and CPPD aggregates.
authors.affiliation: Cattedra di Reumatologia, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: W
authors.initials: W
authors.lastname: Grassi
authors.forename: G
authors.initials: G
authors.lastname: Meenagh
authors.forename: E
authors.initials: E
authors.lastname: Pascual
authors.forename: E
authors.initials: E
authors.lastname: Filippucci
mesh_terms: D015210:Arthritis, Gouty / Q000000981:diagnostic imaging*; D002131:Calcium Pyrophosphate / Q000032:analysis*; D002805:Chondrocalcinosis / Q000000981:diagnostic imaging*; D006073:Gout / Q000000981:diagnostic imaging; D006801:Humans; D014463:Ultrasonography
chemical_list: D002131:Calcium Pyrophosphate