title: CT evaluation of small polypoid lesions of the gallbladder.
abstract: OBJECTIVE
  The ability of CT to differentiate small polypoid lesions of the gallbladder was evaluated.
  
  
  METHODS
  CT followed by cholecystectomy was performed in 20 patients with small polypoid lesions (< or = 20mm) of the gallbladder measured by preoperative ultrasonography. Detectability of the lesions on both unenhanced and enhanced CT, and the configuration and density of the polypoid lesions on enhanced CT were evaluated in comparison with histopathology.
  
  
  RESULTS
  Unenhanced CT detected 8 of 20 polypoid lesions (40%), whereas enhanced CT detected all lesions. All the cholesterol polyp (n = 9) and hyperplastic polyp (n = 2) were not detected on unenhanced CT. Configurations of the polypoid lesions were classified into three types; pedunculated, sessile, and mass forming type. All of cholesterol polyp and hyperplastic polyp were demonstrated as pedunculated type, and adenomyomatosis (n = 2) as mass forming type in all lesions, respectively. Two of adenoma were seen as pedunculated type in one and as mass forming type in the other. Adenocarcinoma (n = 5) was depicted as sessile type in four lesions and as pedunculated type in one. The density of the lesions compared with the liver parenchyma on enhanced CT was not specific.
  
  
  CONCLUSIONS
  The configuration of polypoid lesions depicted on enhanced CT and visualization of them on unenhanced CT are helpful in differentiating neoplastic lesions which should be resected from other benign lesions.
authors.affiliation: Department of Diagnostic Radiology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Furukawa
authors.forename: K
authors.initials: K
authors.lastname: Takayasu
authors.forename: K
authors.initials: K
authors.lastname: Mukai
authors.forename: K
authors.initials: K
authors.lastname: Inoue
authors.forename: T
authors.initials: T
authors.lastname: Kyokane
authors.forename: K
authors.initials: K
authors.lastname: Shimada
authors.forename: T
authors.initials: T
authors.lastname: Kosuge
authors.forename: K
authors.initials: K
authors.lastname: Ushio
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D018256:Adenomatous Polyps / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D018194:Adenomyoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D002763:Cholecystectomy; D003937:Diagnosis, Differential; D005704:Gallbladder / Q000473:pathology; D005706:Gallbladder Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D006801:Humans; D006965:Hyperplasia; D011127:Polyps / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D014057:Tomography, X-Ray Computed