title: Automatic radiation dose monitoring for CT of trauma patients with different protocols: feasibility and accuracy.
abstract: OBJECTIVE
  To demonstrate the feasibility and accuracy of automatic radiation dose monitoring software for computed tomography (CT) of trauma patients in a clinical setting over time, and to evaluate the potential of radiation dose reduction using iterative reconstruction (IR).
  
  
  METHODS
  In a time period of 18 months, data from 378 consecutive thoraco-abdominal CT examinations of trauma patients were extracted using automatic radiation dose monitoring software, and patients were split into three cohorts: cohort 1, 64-section CT with filtered back projection, 200 mAs tube current-time product; cohort 2, 128-section CT with IR and identical imaging protocol; cohort 3, 128-section CT with IR, 150 mAs tube current-time product. Radiation dose parameters from the software were compared with the individual patient protocols. Image noise was measured and image quality was semi-quantitatively determined.
  
  
  RESULTS
  Automatic extraction of radiation dose metrics was feasible and accurate in all (100%) patients. All CT examinations were of diagnostic quality. There were no differences between cohorts 1 and 2 regarding volume CT dose index (CTDIvol; p=0.62), dose-length product (DLP), and effective dose (ED, both p=0.95), while noise was significantly lower (chest and abdomen, both -38%, p<0.017). Compared to cohort 1, CTDIvol, DLP, and ED in cohort 3 were significantly lower (all -25%, p<0.017), similar to the noise in the chest (-32%) and abdomen (-27%, both p<0.017). Compared to cohort 2, CTDIvol (-28%), DLP, and ED (both -26%) in cohort 3 was significantly lower (all, p<0.017), while noise in the chest (+9%) and abdomen (+18%) was significantly higher (all, p<0.017).
  
  
  CONCLUSIONS
  Automatic radiation dose monitoring software is feasible and accurate, and can be implemented in a clinical setting for evaluating the effects of lowering radiation doses of CT protocols over time.
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Switzerland.
authors.forename: K
authors.initials: K
authors.lastname: Higashigaito
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Switzerland.
authors.forename: A S
authors.initials: AS
authors.lastname: Becker
authors.affiliation: Division of Trauma Surgery, University Hospital Zurich, University of Zurich, Switzerland.
authors.forename: K
authors.initials: K
authors.lastname: Sprengel
authors.affiliation: Division of Trauma Surgery, University Hospital Zurich, University of Zurich, Switzerland.
authors.forename: H-P
authors.initials: HP
authors.lastname: Simmen
authors.affiliation: Division of Trauma Surgery, University Hospital Zurich, University of Zurich, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Wanner
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Switzerland. Electronic address: hatem.alkadhi@usz.ch.
authors.forename: H
authors.initials: H
authors.lastname: Alkadhi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061214:Patient Safety; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000032:analysis* / Q000517:prevention & control; D011835:Radiation Protection / Q000379:methods*; D011874:Radiometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012984:Software; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014584:User-Computer Interface; D014947:Wounds and Injuries / Q000000981:diagnostic imaging*; D055815:Young Adult