title: Effect of the forward-projected model-based iterative reconstruction solution algorithm on image quality and radiation dose in pediatric cardiac computed tomography.
abstract: BACKGROUND
  Some iterative reconstruction algorithms are useful for reducing the radiation dose in pediatric cardiac CT. A new iterative reconstruction algorithm (forward-projected model-based iterative reconstruction solution) has been developed, but its usefulness for radiation dose reduction in pediatric cardiac CT is unknown.
  
  
  OBJECTIVE
  To investigate the effect of the new algorithm on CT image quality and on radiation dose in pediatric cardiac CT.
  
  
  METHODS
  We obtained phantom data at six dose levels, as well as pediatric cardiac CT data, and reconstructed CT images using filtered back projection, adaptive iterative dose reduction 3-D (AIDR 3-D) and the new algorithm. We evaluated phantom image quality using physical assessment. Four radiologists performed visual evaluation of cardiac CT image quality.
  
  
  RESULTS
  In the phantom study, the new algorithm effectively suppressed noise in the low-dose range and moderately generated modulation transfer function, yielding a higher signal-to-noise ratio compared with filtered back projection or AIDR 3-D. When clinical cardiac CT was performed, images obtained by the new method had less perceived image noise and better tissue contrast at similar resolution compared with AIDR 3-D images.
  
  
  CONCLUSIONS
  The new algorithm reduced image noise at moderate resolution in low-dose CT scans and improved the perceived quality of cardiac CT images to some extent. This new algorithm might be superior to AIDR 3-D for radiation dose reduction in pediatric cardiac CT.
authors.affiliation: Department of Radiology, Shimane University Hospital, 89-1 Enya-cho, Izumo-shi, Shimane, 693-8501, Japan. nyukako@med.shimane-u.ac.jp.
authors.forename: Yukako
authors.initials: Y
authors.lastname: Nishiyama
authors.affiliation: Department of Radiology, Shimane University Hospital, 89-1 Enya-cho, Izumo-shi, Shimane, 693-8501, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Tada
authors.affiliation: Department of Radiology, Shimane University Faculty of Medicine, Shimane, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Nishiyama
authors.affiliation: Department of Radiology, Shimane University Faculty of Medicine, Shimane, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mori
authors.affiliation: Department of Radiology, Shimane University Faculty of Medicine, Shimane, Japan.
authors.forename: Mitsunari
authors.initials: M
authors.lastname: Maruyama
authors.affiliation: Department of Radiology, Shimane University Faculty of Medicine, Shimane, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Katsube
authors.affiliation: Department of Radiology, Shimane University Faculty of Medicine, Shimane, Japan.
authors.forename: Nobuko
authors.initials: N
authors.lastname: Yamamoto
authors.affiliation: Department of Radiology, Shimane University Hospital, 89-1 Enya-cho, Izumo-shi, Shimane, 693-8501, Japan.
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Kanayama
authors.affiliation: Department of Radiology, Shimane University Hospital, 89-1 Enya-cho, Izumo-shi, Shimane, 693-8501, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yamamoto
authors.affiliation: Department of Radiology, Shimane University Faculty of Medicine, Shimane, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Kitagaki
mesh_terms: D000465:Algorithms; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D007223:Infant; D008297:Male; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Cardiac; Children; Computed tomography; Congenital heart disease; Image quality; Iterative reconstruction; Phantom study; Radiation dose