title: Conventional and hydrocolonic US of the appendix with CT correlation performed by on-call radiology residents.
abstract: OBJECTIVE
  The purpose of this study was to assess the feasibility and accuracy of emergent hydrocolonic ultrasonography (US) performed by on-call residents in patients suspected of having appendicitis.
  
  
  METHODS
  Thirty-one patients with a clinically equivocal diagnosis of appendicitis were prospectively evaluated with conventional US, hydrocolonic US, and appendiceal computed tomography (CT). Midlevel radiology residents performed the US examinations while they were on call. Sensitivity, specificity, and accuracy for diagnosing appendicitis were calculated for conventional and hydrocolonic US by using clinical outcome as the standard. Results of US and CT of the appendix were also correlated. Residents recorded their diagnostic confidence for conventional and hydrocolonic US. All patients were able to hold the rectally administered contrast material until completion of both hydrocolonic US and appendiceal CT.
  
  
  RESULTS
  The sensitivity for detecting appendicitis with conventional US, hydrocolonic US, and appendiceal CT was 50%, 75%, and 100%, respectively. Specificity was 96%, 93%, and 93%, respectively. Identification of the normal and abnormal appendix improved from 13% (four of 31 patients) with conventional US to 35% (11 of 31 patients) with hydrocolonic US. The radiology residents' diagnostic confidence increased from 0.74 with conventional US to 0.83 with hydrocolonic US.
  
  
  CONCLUSIONS
  Hydrocolonic US is a feasible addition to conventional US examination for patients suspected of having appendicitis. It improves sensitivity, increases radiology residents' confidence, and is well tolerated by patients.
authors.affiliation: Department of Radiology, University of Chicago Hospitals, IL 60637, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Kan
authors.forename: B P
authors.initials: BP
authors.lastname: Fines
authors.forename: B
authors.initials: B
authors.lastname: Funaki
mesh_terms: D000293:Adolescent; D000328:Adult; D001064:Appendicitis / Q000000981:diagnostic imaging*; D001065:Appendix / Q000000981:diagnostic imaging*; D003106:Colon / Q000000981:diagnostic imaging*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007396:Internship and Residency; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011871:Radiology; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
chemical_list: D003287:Contrast Media