title: Can experienced CT radiologists use technique parameters to predict excessive patient dose? An analysis of the ACR CT accreditation database.
abstract: OBJECTIVE
  The aim of this study was to determine, for 3 basic clinical examinations, whether blinded, experienced CT radiologists participating in the ACR's CT Accreditation Program could use scan parameters such as tube current-time product (mAs), tube voltage (kVp), and pitch to predict scanner output settings, expressed as weighted CT dose index (CTDIw) and volume CT dose index (CTDIvol), exceeding CTDIw diagnostic reference levels (DRLs) set by the ACR in 2002 and CTDIvol DRLs adopted by the ACR in 2008.
  
  
  METHODS
  CT sites with 829 scanners submitted examinations to the ACR between 2002 and 2004, yielding 518 eligible examinations for analysis (138 adult head CT scans, 333 adult abdominal CT scans, and 47 pediatric abdominal CT scans). The sites' measured CTDIw values for each type of examination were compared with the ACR's CTDIw DRLs in effect from 2002 to 2004 and compared with comments regarding excessively high mAs or kVp made by radiologist clinical reviewers to determine if excessively high-dose index measurements could be predicted. The same analysis was repeated using CTDIvol DRLs adopted by the ACR in 2008 and compared with excessively high mAs or kVp and excessively low-pitch comments.
  
  
  RESULTS
  Excessively high mAs or kVp comments yielded sensitivity of only 21.2% in predicting examinations above the CTDIw DRLs, with specificity of 87.6%. Using the 2008 CTDIvol DRLs, the corresponding sensitivity was 13.1% and specificity was 86.2%. Significance was not achieved for use of clinical parameters in predicting either the CTDIw or CTDIvol.
  
  
  CONCLUSIONS
  Experienced CT radiologists cannot reliably use scan parameters to predict examinations that exceed CTDIw or CTDIvol DRLs.
authors: George Washington University Medical Center, Washington, District of Columbia 20037, USA. gwuradrz@yahoo.com
authors: Robert K
authors: RK
authors: Zeman
authors: Vincent
authors: V
authors: Herlihy
authors: Theresa A
authors: TA
authors: Branham
authors: Mythreyi
authors: M
authors: Bhargavan
authors: Krista M
authors: KM
authors: Bush
authors: Cynthia H
authors: CH
authors: McCollough
mesh_terms: D000068:Accreditation; D002983:Clinical Competence; D016208:Databases, Factual; D004521:Educational Measurement / Q000379:methods*; D006801:Humans; D011237:Predictive Value of Tests; D011829:Radiation Dosage; D012955:Societies, Medical; D014057:Tomography, X-Ray Computed / Q000592:standards*; D014481:United States