title: Sonographic findings of active Clonorchis sinensis infection.
abstract: OBJECTIVE
  The aim of this study was to document the characteristic sonographic findings of clonorchiasis for the diagnosis of active infection in an endemic area.
  
  
  METHODS
  In a village in northeastern China, residents underwent fecal examinations for detection of Clonorchis sinensis eggs. Shortly thereafter, residents were examined with abdominal sonography. An experienced radiologist performed the sonographic examinations and analyzed the findings. Subjects whose fecal examinations were positive for eggs were considered to have active clonorchiasis; those whose examinations were negative for eggs were used as control subjects. The distinguishing sonographic features of active clonorchiasis were identified by stepwise logistic regression analysis.
  
  
  RESULTS
  The study population comprised 457 subjects; fecal examinations revealed C. sinensis eggs in 316 and no eggs in 141. Four sonographic findings distinguished subjects with active clonorchiasis from control subjects: increased periductal echogenicity (p < 0.001; R = 0.11; sensitivity, 35%; specificity, 91%), floating echogenic foci in the gallbladder (p < 0.001; R = 0.09; sensitivity, 28%; specificity, 94%), diffuse dilatation of the intrahepatic bile ducts (p < 0.01; R = 0.03; sensitivity, 67%; specificity, 48%), and gallbladder distention (p < 0.05; R = 0.02; sensitivity, 3%; specificity, 100%), in decreasing order of significance. Among these 4 sonographic findings, increased periductal echogenicity and floating echogenic foci in the gallbladder were more significantly associated with active infection than were the other 2.
  
  
  CONCLUSIONS
  Increased periductal echogenicity and floating echogenic foci in the gallbladder were identified as the 2 most significant findings for the sonographic diagnosis of active C. sinensis infection.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710, Korea.
authors.forename: Dongil
authors.initials: D
authors.lastname: Choi
authors.forename: Sung-Tae
authors.initials: ST
authors.lastname: Hong
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Lim
authors.forename: Seung-Yull
authors.initials: SY
authors.lastname: Cho
authors.forename: Han-Jong
authors.initials: HJ
authors.lastname: Rim
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Ji
authors.forename: Ren
authors.initials: R
authors.lastname: Yuan
authors.forename: Shuyu
authors.initials: S
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D001653:Bile Ducts, Intrahepatic / Q000000981:diagnostic imaging*; D002681:China / Q000453:epidemiology; D003003:Clonorchiasis / Q000000981:diagnostic imaging* / Q000453:epidemiology; D003004:Clonorchis sinensis / Q000302:isolation & purification; D019353:Endemic Diseases; D005243:Feces / Q000469:parasitology; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014463:Ultrasonography