title: Imaging indexes of activity and severity for Crohn's disease: current status and future trends.
abstract: BACKGROUND
  Cross-sectional imaging techniques, including ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) are increasingly used for evaluation of Crohn's disease (CD).
  
  
  OBJECTIVE
  To review the accuracy of cross-sectional imaging indexes for measurement of disease activity and severity in patients with CD, and to evaluate its applicability on daily clinical practice and research.
  
  
  METHODS
  Relevant publications were identified by literature search, and selected based on predefined quality parameters, including a sample size and reference standard. Nineteen publications were chosen.
  
  
  RESULTS
  The US-based indexes of activity showed high correlation with reference standard indexes. There is a good or very good agreement between the MR-based indexes and the reference standard when the comparison is limited to small segments of intestine. Significant discrepancies have been found between indexes that evaluate the colon. Only one CT-based index was included. The main strengths and weaknesses of the indexes, according to its design, are discussed.
  
  
  CONCLUSIONS
  Standardization of image acquisition protocols and patient preparation should be procured, especially for MRI. In daily practice, a simple, semi-quantitative index providing relevant information on disease activity and severity is preferable. For research purposes, a precise and reproducible index should be mandatory.
authors.affiliation: Department of Radiology, Centro de Investigaciones Biomédicas en Red, Enfermedades Hepáticas y Digestivas, IDIBAPS, Hospital Clínic of Barcelona, Villarroel 170, 08036 Barcelona, Spain. jrimola@clinic.ub.es
authors.forename: Jordi
authors.initials: J
authors.lastname: Rimola
authors.forename: Ingrid
authors.initials: I
authors.lastname: Ordás
authors.forename: Sonia
authors.initials: S
authors.lastname: Rodríguez
authors.forename: Elena
authors.initials: E
authors.lastname: Ricart
authors.forename: Julián
authors.initials: J
authors.lastname: Panés
mesh_terms: D003113:Colonoscopy; D003424:Crohn Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D003952:Diagnostic Imaging / Q000592:standards* / Q000639:trends*; D006801:Humans; D007082:Ileum / Q000473:pathology; D008279:Magnetic Resonance Imaging; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography