title: Ultrasonography as an adjunct in the diagnosis of acute appendicitis: a 4-year experience.
abstract: This study was designed to evaluate the sensitivity and specificity of abdominal ultrasonography as a diagnostic modality in a large series of children who presented with possible appendicitis. From August 1990 to July 1994, 452 children (203 boys, 249 girls) with an average age of 11 years (range, 1 to 20 years) underwent graded compression ultrasonography of the right lower quadrant of the abdomen for the evaluation of possible appendicitis. In the first 18 months of the study all patients with the possible diagnosis of appendicitis (group I; 180 patients) had abdominal ultrasonography after members of the surgical team evaluated and documented their findings in the medical record. In the second study period (30 months), abdominal ultrasonography was recommended only when the clinical diagnosis of acute appendicitis was equivocal (group II; 272 patients). Abdominal ultrasonography was performed using the graded compression technique with a 5.0-MHz linear array transducer. A positive ultrasound study for appendicitis was defined as the presence of an enlarged noncompressible appendix with an outer wall to outer wall diameter of greater than 6 mm, the presence of a complex mass, or the presence of an appendicolith. The sonographic data were correlated with surgical and pathological findings. Appendicitis was confirmed in 112 of the 452 cases. In 17 of these, the appendix was perforated. In the overall group of 452 children, abdominal ultrasonography had a sensitivity of 90%, specificity of 96%, and accuracy of 95%. There was no significant morbidity in the 11 patients with a false-negative study result. All 11 patients had an uncomplicated appendectomy. There were 11 false-positive results; 10 of these patients had a negative laparotomy result (negative laparatomy rate, 8.9%). For the two groups, the sensitivity and specificity of ultrasonography in the diagnosis of appendicitis were equivalent (group 1: 88% sensitivity, 96% specificity; group 2: 92% sensitivity, 97% specificity). On the basis of the high sensitivity and specificity rates, ultrasonography of the appendix can be a useful adjunct to standard examination in the diagnosis of acute appendicitis.
authors.affiliation: Department of Surgery, Children's National Medical Center, Washington, D.C. 20010, USA.
authors.forename: P
authors.initials: P
authors.lastname: Ramachandran
authors.forename: C J
authors.initials: CJ
authors.lastname: Sivit
authors.forename: K D
authors.initials: KD
authors.lastname: Newman
authors.forename: M Z
authors.initials: MZ
authors.lastname: Schwartz
mesh_terms: D015746:Abdominal Pain / Q000000981:diagnostic imaging* / Q000209:etiology; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D001064:Appendicitis / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012680:Sensitivity and Specificity; D014463:Ultrasonography