title: Effects of Dual-Energy Technique on Radiation Exposure and Image Quality in Pediatric Body CT.
abstract: OBJECTIVE
  The purpose of this study was to assess the effects of dual-energy CT (DECT) on radiation exposure and image quality in pediatric body CT.
  
  
  METHODS
  This retrospective study included 79 children (median age, 10.1 years; range, 12 days-18 years) who underwent thoracic or abdominal-pelvic CT or CT angiography with dual-energy technique between October 2014 and March 2015. The delivered volume CT dose index (CTDIvol) from DECT was recorded and compared with the estimated CTDIvolhad the patient undergone scanning with a standard single-energy CT (SECT) protocol. Size-specific dose estimates were calculated for both DECT and SECT. Image quality was subjectively scored (scale, 1-4). For 16 of 79 patients who underwent both DECT and SECT, image contrast and noise were measured and contrast-to-noise ratio calculated. Parametric and nonparametric testing of independent and paired samples was performed.
  
  
  RESULTS
  For all 79 studies, actual median CTDIvoland size-specific dose estimate were 3.7 and 5.9 mGy for DECT versus prescanning estimates of 4.4 and 7.7 mGy for SECT, resulting in 12.5% and 11.2% radiation exposure reduction (p < 0.01). Diagnostic image quality was achieved in all patients. In the 16-patient subset, the median CTDIvolvalues of DECT and SECT were 3.1 and 3.4 mGy (p < 0.05). Median noise was greater with DECT than with SECT (p < 0.01), but the mean contrast-to-noise ratios for the liver and portal vein were similar (liver, p = 0.32; portal vein, p = 0.21).
  
  
  CONCLUSIONS
  In pediatric body CT, the use of DECT results in radiation exposures comparable to or less than those of SECT while maintaining contrast and contrast-to-noise ratio.
authors.affiliation: 1 Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S Kingshighway Blvd, Saint Louis, MO 63110.
authors.forename: Marilyn J
authors.initials: MJ
authors.lastname: Siegel
authors.affiliation: 1 Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S Kingshighway Blvd, Saint Louis, MO 63110.
authors.forename: Will A
authors.initials: WA
authors.lastname: Curtis
authors.affiliation: 2 Siemens Healthcare USA, Malvern, PA.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Ramirez-Giraldo
keywords: dual-energy CT; image noise; pediatrics; radiation exposure