title: Development of DICOM image-based CT low dose simulator using fan-beam transform.
abstract: BACKGROUND
  Projection-data based method is established as an accurate simulation of low-dose CT, but cooperation of the CT manufacturer is required. Image-based method is awaited for independent and efficient research.
  
  
  OBJECTIVE
  To develop and verify image-based method for adding noise to DICOM images.
  
  
  METHODS
  This technique reproduces projection data by fan-beam transform of the DICOM image data and by creating and reconstructing noise projections into a noise image that can be added to the original image. A cylindrical test phantom and anthropomorphic phantom were used to verify the simulation method for both standard and adaptive iterative reconstruction methods.
  
  
  RESULTS
  The simulated images compared favorably with actual images. Standard deviation difference of the simulated images were 1.27% ± 0.81% (cylindrical phantom) and ranged from 1.61% ± 0.81% (head), to 5.41% ± 1.57% (hepatic portal region) (anthropomorphic phantom). The standard deviation difference of the cylindrical phantom with the adaptive iterative technique were 3.41% ± 1.76% at 50% ASIR and 3.85% ± 1.82% at 100% ASIR. The simulated noise power spectra of both types of images were comparable to the actual images.
  
  
  CONCLUSIONS
  We developed and validated a DICOM image-based low-dose simulation that allows researchers to perform dose reduction research independently and efficiently.
authors.affiliation: Department of Medical Physics and Engineering, Division of Medical Technology and Science, Course of Health Science, Graduate School of Medicine, Osaka University, Osaka, Japan Department of Radiology, National Center for Child Health and Development, Tokyo, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Horiuchi
authors.forename: Shuji
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Kenya
authors.initials: K
authors.lastname: Murase
mesh_terms: D002138:Calibration; D003627:Data Interpretation, Statistical; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*
keywords: CT; Computed tomography; computer simulation; dose reduction; noise