title: Acute ankle trauma: value of a short dedicated extremity MR imaging examination in prediction of need for treatment.
abstract: OBJECTIVE
  To assess predictive value of a short magnetic resonance (MR) imaging examination with or instead of radiography performed in patients with acute ankle trauma to identify those who require additional treatment versus those who do not and can be discharged without further follow-up.
  
  
  METHODS
  Informed consent was obtained from all participating patients, and the institutional review board approved the randomized controlled trial and use of data to create prediction models. In a prospective controlled trial, 197 patients with recent ankle trauma (92 women, 105 men) were randomized into two groups: those who underwent radiography and those who underwent a combination of radiography and MR imaging. Data about side of injury, trauma mechanism, and results of radiography and MR imaging were collected. Additional treatment was necessary in 109 of 197 patients after their initial hospital visit. With univariable and multivariable regression analysis, four models were created for prediction of treatment.
  
  
  RESULTS
  In univariable analysis, age (odds ratio [OR], 1.02; 95% confidence interval: 1.00, 1.04), radiographic results (OR, 7.92; 95% confidence interval: 3.17, 19.8), and positive or uncertain results in patients who underwent MR imaging versus patients who did not (OR, 2.42; 95% confidence interval: 1.25, 4.70) were predictive of treatment. In the multivariable analysis, positive or uncertain MR imaging results (OR, 2.61; 95% confidence interval: 1.28, 5.30) contributed significantly to prediction of subsequent treatment. Negative MR imaging results did not contribute significantly (OR, 0.66; 95% confidence interval: 0.27, 1.61).
  
  
  CONCLUSIONS
  A limited MR imaging examination in initial evaluation of acute ankle injury with radiography has additional predictive value in identification of patients who need treatment but does not add significant information in identification of those who can be discharged without further follow-up. A limited MR imaging examination cannot replace radiography for prediction of need for additional treatment.
authors.affiliation: Program for the Assessment of Radiological Technology, Erasmus MC, University Medical Center Rotterdam, Dr Molewaterplein 40, 3015 GD Rotterdam, The Netherlands.
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Nikken
authors.forename: Edwin H G
authors.initials: EH
authors.lastname: Oei
authors.forename: Abida Z
authors.initials: AZ
authors.lastname: Ginai
authors.forename: Gabriel P
authors.initials: GP
authors.lastname: Krestin
authors.forename: Jan A N
authors.initials: JA
authors.lastname: Verhaar
authors.forename: Arie B
authors.initials: AB
authors.lastname: van Vugt
authors.forename: M G Myriam
authors.initials: MG
authors.lastname: Hunink
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016512:Ankle Injuries / Q000175:diagnosis* / Q000000981:diagnostic imaging; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011859:Radiography