title: MR imaging of skeletal soft tissue infection: utility of diffusion-weighted imaging in detecting abscess formation.
abstract: OBJECTIVE
  Our objectives were to assess if diffusion-weighted imaging (DWI) can help identify abscess formation in the setting of soft tissue infection and to assess whether abscess formation can be diagnosed confidently with a combination of DWI and other unenhanced sequences.
  
  
  METHODS
  Eight cases of soft tissue infection imaged with MRI including DWI were retrospectively reviewed.
  
  
  RESULTS
  Two male and six female patients were studied (age range 23-50 years). Unenhanced MRI including DWI was performed in all patients. Post-contrast images were obtained in seven patients. All patients had clinically or surgically confirmed abscesses. Abscesses demonstrated restricted diffusion. DWI in conjunction with other unenhanced imaging showed similar confidence levels as post-contrast images in diagnosing abscess formation in four cases. In two cases, although the combined use of DWI and other unenhanced imaging yielded the same confidence levels as post-contrast imaging, DWI was more definitive for demonstrating abscess formation. In one case, post-contrast images had a better confidence for suggesting abscess. In one case, DWI helped detected the abscess, where gadolinium could not be administered because of a contraindication.
  
  
  CONCLUSIONS
  This preliminary study suggests that DWI is a useful adjunct in the diagnosis of skeletal soft tissue abscesses.
authors.affiliation: Department of Radiology, McMaster University, Hamilton, Ontario, Canada, L8N 2A6. sriniharish@gmail.com
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Harish
authors.forename: Mary M
authors.initials: MM
authors.lastname: Chiavaras
authors.forename: Nikhil
authors.initials: N
authors.lastname: Kotnis
authors.forename: Ryan
authors.initials: R
authors.lastname: Rebello
mesh_terms: D000038:Abscess / Q000175:diagnosis* / Q000209:etiology*; D000328:Adult; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005208:Fasciitis / Q000150:complications* / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009220:Myositis / Q000150:complications* / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity