title: Eliminating unenhanced CT when evaluating abdominal neoplasms in children.
abstract: OBJECTIVE
  The purpose of our study was to evaluate a CT protocol that eliminates the unenhanced phase for imaging pediatric abdominal neoplasms.
  
  
  METHODS
  We retrospectively performed a case series study of all the abdominal CT scans on children and adolescents found in our archives. Two radiologists separately evaluated each CT scan twice. The radiologists were separately asked to formulate the most probable diagnosis and to decide whether tumor calcification was present. The first evaluation was performed without the unenhanced phase and the second was done with both the unenhanced and the contrast-enhanced scans. The agreement between the two methods, and that between each method and the histopathologic results, were measured using kappa statistics. The sensitivity and specificity of each method for diagnosing the more frequent neoplasms were also measured. The sensitivity and specificity of the contrast-enhanced CT scans were assessed for detecting calcification without reference to the unenhanced scan.
  
  
  RESULTS
  A total of 131 CT scans were evaluated. The agreement between diagnoses from the two methods was almost perfect for both radiologists (kappa = 0.97 and 0.99). No statistically significant difference was seen between the two methods and the histopathologic results. The sensitivity and specificity of the two methods for the most frequent neoplasms were similar. The evaluations without the unenhanced phase showed good sensitivity and specificity for tumor calcifications.
  
  
  CONCLUSIONS
  CT protocols without the unenhanced phase are a viable alternative for evaluating abdominal neoplasms in children and adolescents.
authors.affiliation: Postgraduate in Children and Adolescent Health, Federal University of Pernambuco, Ave. Professor Moraes Rego, 1235 Cidade University, Recife, Pernambuco 50670-901, Brazil. eduardojust@ig.com.br
authors.forename: Eduardo Just
authors.initials: EJ
authors.lastname: da Costa e Silva
authors.forename: Gisélia Alves Pontes
authors.initials: GA
authors.lastname: da Silva
mesh_terms: D000008:Abdominal Neoplasms / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*