title: Validation of a low dose simulation technique for computed tomography images.
abstract: OBJECTIVE
  Evaluation of a new software tool for generation of simulated low-dose computed tomography (CT) images from an original higher dose scan.
  
  
  METHODS
  Original CT scan data (100 mAs, 80 mAs, 60 mAs, 40 mAs, 20 mAs, 10 mAs; 100 kV) of a swine were acquired (approved by the regional governmental commission for animal protection). Simulations of CT acquisition with a lower dose (simulated 10-80 mAs) were calculated using a low-dose simulation algorithm. The simulations were compared to the originals of the same dose level with regard to density values and image noise. Four radiologists assessed the realistic visual appearance of the simulated images.
  
  
  RESULTS
  Image characteristics of simulated low dose scans were similar to the originals. Mean overall discrepancy of image noise and CT values was -1.2% (range -9% to 3.2%) and -0.2% (range -8.2% to 3.2%), respectively, p>0.05. Confidence intervals of discrepancies ranged between 0.9-10.2 HU (noise) and 1.9-13.4 HU (CT values), without significant differences (p>0.05). Subjective observer evaluation of image appearance showed no visually detectable difference.
  
  
  CONCLUSIONS
  Simulated low dose images showed excellent agreement with the originals concerning image noise, CT density values, and subjective assessment of the visual appearance of the simulated images. An authentic low-dose simulation opens up opportunity with regard to staff education, protocol optimization and introduction of new techniques.
authors.affiliation: Department of Radiology, Technische Universitaet Muenchen, Munich, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Muenzel
authors.affiliation: Philips Technologie GmbH, Innovative Technologies, Hamburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Koehler
authors.affiliation: Philips Healthcare, Cleveland, Ohio, United States of America.
authors.forename: Kevin
authors.initials: K
authors.lastname: Brown
authors.affiliation: Philips Healthcare, Cleveland, Ohio, United States of America.
authors.forename: Stanislav
authors.initials: S
authors.lastname: Zabić
authors.affiliation: Department of Radiology, Technische Universitaet Muenchen, Munich, Germany.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Fingerle
authors.affiliation: Department of Radiology, Technische Universitaet Muenchen, Munich, Germany.
authors.forename: Simone
authors.initials: S
authors.lastname: Waldt
authors.affiliation: Department of Radiology, Technische Universitaet Muenchen, Munich, Germany.
authors.forename: Edgar
authors.initials: E
authors.lastname: Bendik
authors.affiliation: Department of Radiology, Technische Universitaet Muenchen, Munich, Germany.
authors.forename: Tina
authors.initials: T
authors.lastname: Zahel
authors.affiliation: MITI - Minimal-invasive Interdisciplinary therapeutic intervention research group, Technische Universitaet Muenchen, Munich, Germany.
authors.forename: Armin
authors.initials: A
authors.lastname: Schneider
authors.affiliation: Department of Radiology, Technische Universitaet Muenchen, Munich, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Dobritz
authors.affiliation: Department of Radiology, Technische Universitaet Muenchen, Munich, Germany.
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Rummeny
authors.affiliation: Department of Radiology, Technische Universitaet Muenchen, Munich, Germany.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Noël
mesh_terms: D000818:Animals; D005260:Female; D023421:Models, Animal; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012986:Software Validation; D013552:Swine; D014057:Tomography, X-Ray Computed / Q000379:methods*