title: Iterative reconstruction technique with reduced volume CT dose index: diagnostic accuracy in pediatric acute appendicitis.
abstract: BACKGROUND
  Iterative reconstruction technique has been proposed as a means of reducing patient radiation dose in pediatric CT. Yet, the effect of such reductions on diagnostic accuracy has not been thoroughly evaluated.
  
  
  OBJECTIVE
  This study compares accuracy of diagnosing pediatric acute appendicitis using contrast-enhanced abdominopelvic CT scans performed with traditional pediatric weight-based protocols and filtered back projection reconstruction vs. a filtered back projection/iterative reconstruction technique blend with reduced volume CT dose index (CTDIvol).
  
  
  METHODS
  Results of pediatric contrast-enhanced abdominopelvic CT scans done for pain and/or suspected appendicitis were reviewed in two groups: A, 192 scans performed with the hospital's established weight-based CT protocols and filtered back projection reconstruction; B, 194 scans performed with iterative reconstruction technique and reduced CTDIvol. Reduced CTDIvol was achieved primarily by reductions in effective tube current-time product (mAseff) and tube peak kilovoltage (kVp). CT interpretation was correlated with clinical follow-up and/or surgical pathology. CTDIvol, size-specific dose estimates (SSDE) and performance characteristics of the two CT techniques were then compared.
  
  
  RESULTS
  Between groups A and B, mean CTDIvol was reduced by 45%, and mean SSDE was reduced by 46%. Sensitivity, specificity and diagnostic accuracy were 96%, 97% and 96% in group A vs. 100%, 99% and 99% in group B.
  
  
  CONCLUSIONS
  Accuracy in diagnosing pediatric acute appendicitis was maintained in contrast-enhanced abdominopelvic CT scans that incorporated iterative reconstruction technique, despite reductions in mean CTDIvol and SSDE by nearly half as compared to the hospital's traditional weight-based protocols.
authors.affiliation: Department of Diagnostic Radiology, DC7R, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, Portland, OR, 97239, USA.
authors.forename: Ryne A
authors.initials: RA
authors.lastname: Didier
authors.forename: Petra L
authors.initials: PL
authors.lastname: Vajtai
authors.forename: Katharine L
authors.initials: KL
authors.lastname: Hopkins
mesh_terms: D001064:Appendicitis / Q000000981:diagnostic imaging*; D002648:Child; D003287:Contrast Media; D005260:Female; D006801:Humans; D008297:Male; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D011860:Radiography, Abdominal; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media