title: Diagnostic accuracy of translucency rendering to differentiate polyps from pseudopolyps at 3D endoluminal CT colonography: a feasibility study.
abstract: OBJECTIVE
  The aim of this study was to assess the accuracy of translucency rendering (TR) in computed tomographic (CT) colonography without cathartic preparation using primary 3D reading.
  
  
  METHODS
  From 350 patients with 482 endoscopically verified polyps, 50 pathologically proven polyps and 50 pseudopolyps were retrospectively examined. For faecal tagging, all patients ingested 140 ml of orally administered iodinated contrast agent (diatrizoate meglumine and diatrizoate sodium) at meals 48 h prior to CT colonography examination and two h prior to scanning. CT colonography was performed using a 64-section CT scanner. Colonoscopy with segmental unblinding was performed within 2 weeks after CT. Three independent radiologists retrospectively evaluated TRCT clonographic images using a dedicated software package (V3D-Colon System). To enable size-dependent statistical analysis, lesions were stratified into the following size categories: small (< or =5 mm), intermediate (6-9 mm), and large (> or =10 mm).
  
  
  RESULTS
  Overall average TR sensitivity for polyp characterisation was 96.6%, and overall average specificity for pseudopolyp characterisation was 91.3%. Overall average diagnostic accuracy (area under the curve) of TR for characterising colonic lesions was 0.97.
  
  
  CONCLUSIONS
  TR is an accurate tool that facilitates interpretation of images obtained with a primary 3D analysis, thus enabling easy differentiation of polyps from pseudopolyps.
authors.affiliation: Department of Radiological Sciences, University of Rome Sapienza, Policlinico Umberto I, Viale Regina Elena 324, 00161 Rome, Italy. antonioguerrisi@msn.com
authors.forename: A
authors.initials: A
authors.lastname: Guerrisi
authors.forename: D
authors.initials: D
authors.lastname: Marin
authors.forename: A
authors.initials: A
authors.lastname: Laghi
authors.forename: M
authors.initials: M
authors.lastname: Di Martino
authors.forename: F
authors.initials: F
authors.lastname: Iafrate
authors.forename: R
authors.initials: R
authors.lastname: Iannaccone
authors.forename: C
authors.initials: C
authors.lastname: Catalano
authors.forename: R
authors.initials: R
authors.lastname: Passariello
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D003111:Colonic Polyps / Q000000981:diagnostic imaging* / Q000473:pathology; D023881:Colonography, Computed Tomographic / Q000379:methods*; D003113:Colonoscopy; D003287:Contrast Media; D003937:Diagnosis, Differential; D003973:Diatrizoate; D006801:Humans; D021621:Imaging, Three-Dimensional; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012984:Software
chemical_list: D003287:Contrast Media; D003973:Diatrizoate