title: Dual-energy computed tomography with advanced postimage acquisition data processing: improved determination of urinary stone composition.
abstract: BACKGROUND
  The characterization of urinary calculi using noninvasive methods has the potential to affect clinical management. CT remains the gold standard for diagnosis of urinary calculi, but has not reliably differentiated varying stone compositions. Dual-energy CT (DECT) has emerged as a technology to improve CT characterization of anatomic structures. This study aims to assess the ability of DECT to accurately discriminate between different types of urinary calculi in an in vitro model using novel postimage acquisition data processing techniques.
  
  
  METHODS
  Fifty urinary calculi were assessed, of which 44 had >or=60% composition of one component. DECT was performed utilizing 64-slice multidetector CT. The attenuation profiles of the lower-energy (DECT-Low) and higher-energy (DECT-High) datasets were used to investigate whether differences could be seen between different stone compositions.
  
  
  RESULTS
  Postimage acquisition processing allowed for identification of the main different chemical compositions of urinary calculi: brushite, calcium oxalate-calcium phosphate, struvite, cystine, and uric acid. Statistical analysis demonstrated that this processing identified all stone compositions without obvious graphical overlap.
  
  
  CONCLUSIONS
  Dual-energy multidetector CT with postprocessing techniques allows for accurate discrimination among the main different subtypes of urinary calculi in an in vitro model. The ability to better detect stone composition may have implications in determining the optimum clinical treatment modality for urinary calculi from noninvasive, preprocedure radiological assessment.
authors.affiliation: Division of Urology, Duke University Medical Center, Durham, North Carolina 27710, USA. michael.ferrandino@duke.edu
authors.forename: Michael N
authors.initials: MN
authors.lastname: Ferrandino
authors.forename: Sean A
authors.initials: SA
authors.lastname: Pierre
authors.forename: Walter Neal
authors.initials: WN
authors.lastname: Simmons
authors.forename: Erik K
authors.initials: EK
authors.lastname: Paulson
authors.forename: David M
authors.initials: DM
authors.lastname: Albala
authors.forename: Glenn M
authors.initials: GM
authors.lastname: Preminger
mesh_terms: D000704:Analysis of Variance; D006801:Humans; D017711:Nonlinear Dynamics; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014545:Urinary Calculi / Q000737:chemistry* / Q000000981:diagnostic imaging*