title: Gout tophus detection-a comparison of dual-energy CT (DECT) and histology.
abstract: OBJECTIVE
  To compare dual-energy CT images (DECT) directly with gold standard histology.
  
  
  METHODS
  A 85-year-old woman with chronic recurrent gouty arthritis and macroscopically visible tophi was assessed with DECT-scans of her feet. When she died 7 days later, three tophi in different regions and in different tissues of her left foot were processed for histological examination.
  
  
  RESULTS
  Of the selected tophi, two were almost completely missed by the color-coding DECT sequences. The tophi remained in most of their volume below the detection threshold value of 150HU (default value).
  
  
  CONCLUSIONS
  It could be demonstrated that DECT only highlights the dense tophi (corresponding of approximately 15-20vol% urate in the tophus). Less dense tophi, despite considerable size, will be missed in the color-coded images.
authors: Clinic of Rheumatology, Luzerner Kantonsspital, 6000 Lucerne 16, Switzerland. Electronic address: ralph.melzer@luks.ch.
authors: Ralph
authors: R
authors: Melzer
authors: Institute of Pathology, Luzerner Kantonsspital, Lucerne, Switzerland.
authors: Chantal
authors: C
authors: Pauli
authors: Institute of Radiology, Luzerner Kantonsspital, Lucerne, Switzerland.
authors: Thomas
authors: T
authors: Treumann
authors: Imaging & Therapy Division, Healthcare Sector, Siemens AG, Forchheim, Germany.
authors: Bernhard
authors: B
authors: Krauss
mesh_terms: D000369:Aged, 80 and over; D015210:Arthritis, Gouty / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D011859:Radiography
keywords: DECT; Dual-energy computed tomography; Gout; Histology; Tophi