title: CT differentiation of adenomyomatosis and gallbladder cancer.
abstract: OBJECTIVE
  The purpose of this study was to determine the accuracy of CT in differentiating adenomyomatosis from gallbladder cancer.
  
  
  METHODS
  We retrospectively identified the cases of 36 patients with pathologically proven adenomyomatosis (n = 22) or gallbladder cancer (n = 14) who had undergone preoperative abdominal CT. Two reviewers independently evaluated the presence and nature of morphologic gallbladder abnormalities, including the presence of intramural diverticula (i.e., small cystic-appearing spaces within the gallbladder wall). The reviewers used a five-point scale (1, definitely absent; 5, definitely present) to rate the overall likelihood of the presence of adenomyomatosis and gallbladder cancer. Ratings were dichotomized such that a diagnosis was considered present at a rating of 4 or 5 and considered absent at lower ratings.
  
  
  RESULTS
  Reviewer 1 detected a morphologic gallbladder abnormality in 17 patients and correctly characterized the abnormality in 14 (82%) of the patients (eight with adenomyomatosis and six with gallbladder cancer). Reviewer 2 detected an abnormality in 18 patients and was correct for 13 (72%) of the patients (eight with adenomyomatosis and five with gallbladder cancer). In particular, reviewer 1 detected intramural diverticula in eight patients, and all had the pathologic diagnosis of adenomyomatosis, whereas reviewer 2 detected intramural diverticula in 11 patients, and eight (73%) had the pathologic diagnosis of adenomyomatosis.
  
  
  CONCLUSIONS
  CT is limited in the detection and differentiation of adenomyomatosis and gallbladder cancer, but the diagnosis of adenomyomatosis can be made with reasonable accuracy when thickening of the gallbladder wall is seen to contain small cystic-appearing spaces.
authors.affiliation: Department of Radiology, University of California, San Francisco, 505 Parnassus Ave., Box 0628, Room M372, San Francisco, CA 94143-0628, USA.
authors.forename: Brian H
authors.initials: BH
authors.lastname: Ching
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Yeh
authors.forename: Antonio C
authors.initials: AC
authors.lastname: Westphalen
authors.forename: Bonnie N
authors.initials: BN
authors.lastname: Joe
authors.forename: Aliya
authors.initials: A
authors.lastname: Qayyum
authors.forename: Fergus V
authors.initials: FV
authors.lastname: Coakley
mesh_terms: D018194:Adenomyoma / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D005706:Gallbladder Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed / Q000379:methods*