title: Pyogenic cerebral abscesses demonstrating facilitated diffusion.
abstract: OBJECTIVE
  Pyogenic cerebral abscesses are associated with high morbidity and mortality when treatment is delayed. Benign clinical presentation, as well as absence of restricted diffusion on MRI may contribute to missed diagnoses and delays. The authors sought to elucidate characteristics associated with facilitated diffusion on the MRIs of patients with pyogenic abscesses.
  
  
  METHODS
  The authors performed a 10-year retrospective review of prospectively attained data for patients undergoing mass resection by a single surgeon.
  
  
  RESULTS
  Our findings show that 3/33 (9%) patients with microbiological diagnoses of cerebral abscesses with a thin ring of contrast enhancement but minimal or no restricted diffusion MRI imaging. All causative organisms were hemolytic streptococci and none of the subjects received antibiotic therapy prior to specimen collection. A trend in these patients was the presence of diabetes and in conjunction with other studies that cite incomplete treatment as being associated with facilitated diffusion, we conjecture that impaired inflammatory responses in some patients may be associated with the absence of restricted diffusion.
  
  
  CONCLUSIONS
  With this in mind, clinicians must maintain a high index of suspicion when assessing patients with cystic, contrast enhancing masses. A prospective multicenter study to compile imaging along with other patient characteristics may help refine the non-invasive diagnostic criteria for brain abscesses.
authors.affiliation: Vivian L. Smith Department of Neurosurgery, University of Texas Health Science Center at Houston, Medical School, Houston, TX, USA.
authors.forename: Saint-Aaron
authors.initials: SA
authors.lastname: Morris
authors.affiliation: Vivian L. Smith Department of Neurosurgery, University of Texas Health Science Center at Houston, Medical School, Houston, TX, USA.
authors.forename: Yoshua
authors.initials: Y
authors.lastname: Esquenazi
authors.affiliation: Vivian L. Smith Department of Neurosurgery, University of Texas Health Science Center at Houston, Medical School, Houston, TX, USA. Electronic address: nitin.tandon@uth.tmc.edu.
authors.forename: Nitin
authors.initials: N
authors.lastname: Tandon
mesh_terms: D000328:Adult; D000368:Aged; D001922:Brain Abscess / Q000000981:diagnostic imaging* / Q000601:surgery*; D038524:Diffusion Magnetic Resonance Imaging; D055459:Facilitated Diffusion; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
keywords: Cerebral abscess; Cystic masses; Diffusion-weighted; Facilitated diffusion; Pyogenic; Restricted diffusion