title: Assessment of polyp and mass histopathology by intravenous contrast-enhanced CT colonography.
abstract: OBJECTIVE
  We sought to demonstrate that intravenous contrast-enhanced CT colonography (CTC) can distinguish colonic adenomas from carcinomas.
  
  
  METHODS
  Supine intravenous contrast-enhanced CTC with colonoscopic and/or surgical correlation was performed on 25 patients with colonic adenomas or carcinomas. Standard deviation of mean polyp CT attenuation was computed and assessed using ANOVA and receiver-operating characteristic analyses.
  
  
  RESULTS
  Colonoscopy confirmed 32 polyps or masses 1 to 8 cm in size. The standard deviations of CT attenuation were carcinomas (n = 13; 36 +/- 6 HU; range 28-48 HU) and adenomas (n = 19; 49 +/- 14 HU; range 31-100 HU) (P = 0.005). At a standard deviation threshold of 42 HU, the sensitivity and specificity for classifying a polyp or mass as a carcinoma were 92% and 79%, respectively. The area under the receiver-operating characteristic curve was 0.89 +/- 0.06 (95% confidence interval 0.73-0.96).
  
  
  CONCLUSIONS
  Measurement of the standard deviation of CT attenuation on intravenous contrast-enhanced CTC permits histopathologic classification of polyps 1 cm or larger as carcinomas versus adenomas. The presence of ulceration or absence of muscular invasion in carcinomas creates overlap with adenomas, reducing the specificity of carcinoma classification.
authors.affiliation: Diagnostic Radiology Department, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bldg. 10, Room 1C351, 10 Center Dr. MSC 1182, Bethesda, MD 20892-1182, USA. rms@nih.gov
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Summers
authors.forename: Adam
authors.initials: A
authors.lastname: Huang
authors.forename: Jianhua
authors.initials: J
authors.lastname: Yao
authors.forename: Shannon R
authors.initials: SR
authors.lastname: Campbell
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Dempsey
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Dwyer
authors.forename: Marek
authors.initials: M
authors.lastname: Franaszek
authors.forename: Danny S
authors.initials: DS
authors.lastname: Brickman
authors.forename: Ingmar
authors.initials: I
authors.lastname: Bitter
authors.forename: Nicholas
authors.initials: N
authors.lastname: Petrick
authors.forename: Amy K
authors.initials: AK
authors.lastname: Hara
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000473:pathology; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003111:Colonic Polyps / Q000000981:diagnostic imaging* / Q000473:pathology; D023881:Colonography, Computed Tomographic; D003113:Colonoscopy; D003287:Contrast Media; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D012372:ROC Curve
chemical_list: D003287:Contrast Media