title: CT differentiation of solid serous cystadenoma vs endocrine tumor of the pancreas.
abstract: OBJECTIVE
  To differentiate between solid serous cystadenoma (SSCA) and endocrine tumor (ET) of the pancreas using dynamic CT findings.
  
  
  METHODS
  Between 2001 and 2008, there were 3 SSCA and 15 ET surgically resected in our institute, for whom preoperative multidetector-row CT were available. Various CT features were retrospectively evaluated by two radiologists in consensus for the differentiation between the two entities. Delay time for early and delayed phase images were 40 and 180 or 240s, respectively. For qualitative assessment, density of the tumors relative to the surrounding parenchyma was evaluated, along with other characteristic features. In patients for whom digital data were available, CT values of the tumors were measured, and quantitative assessment was also performed. Relative and absolute washout rate (RWR and AWR, respectively) were also calculated.
  
  
  RESULTS
  Mean sizes of the two groups were similar. Tumors were seen as low density area more frequently in SSCA than in ET on unenhanced CT (3/3 vs 1/14), and also on the delayed phase image (2/3 vs 0/14) (p<0.05). Fibrous capsule was observed more frequently in SSCA (2/3) than in ET (0/14). CT value of the tumor on unenhanced CT was significantly lower, and RWR was higher in SSCA than in ET (p<0.05, Mann-Whitney's U test). The difference in delayed phase CT density and AWR did not reach statistically significant level.
  
  
  CONCLUSIONS
  Unenhanced and enhanced CT findings may be of value in differentiation between SSCA and ET.
authors.affiliation: Department of Radiology, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku Fukuoka, 814-0180, Japan. khayashi131@gmail.com
authors.forename: Kensei
authors.initials: K
authors.lastname: Hayashi
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Fujimitsu
authors.forename: Mikiko
authors.initials: M
authors.lastname: Ida
authors.forename: Keiko
authors.initials: K
authors.lastname: Sakamoto
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Higashihara
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Hamada
authors.forename: Kengo
authors.initials: K
authors.lastname: Yoshimitsu
mesh_terms: D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D018293:Cystadenoma, Serous / Q000000981:diagnostic imaging* / Q000601:surgery; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*