title: Dose reduction with iterative reconstruction: Optimization of CT protocols in clinical practice.
abstract: OBJECTIVE
  To create an adaptable and global approach for optimizing MDCT protocols by evaluating the influence of acquisition parameters and Iterative Reconstruction (IR) on dose reduction and image quality.
  
  
  METHODS
  MDCT acquisitions were performed on quality image phantom by varying kVp, mAs, and pitch for the same collimation. The raw data were reconstructed by FBP and Sinogram Affirmed Iterative Reconstruction (SAFIRE) with different reconstruction kernel and thickness. A total of 4032 combinations of parameters were obtained. Indices of quality image (image noise, NCT, CNR, SNR, NPS and MTF) were analyzed. We developed a software in order to facilitate the optimization between dose reduction and image quality. Its outcomes were verified on an adult anthropomorphic phantom.
  
  
  RESULTS
  Dose reduction resulted in the increase of image noise and the decrease of SNR and CNR. The use of IR improved these indices for the same dose without affecting NCT and MTF. The image validation was performed by the anthropomorphic phantom. The software proposed combinations of parameters to reduce doses while keeping indices of the image quality adequate. We observed a CTDIvol reduction between -44% and -83% as compared to the French diagnostic reference levels (DRL) for different anatomical localization.
  
  
  CONCLUSIONS
  The software developed in this study may help radiologists in selecting adequate combinations of parameters that allows to obtain an appropriate image with dose reduction.
authors: Department of Radiology, University Hospital Center of Nîmes, EA 2415, Bd Prof Robert-Debré, 30029 Nîmes cedex, France. Electronic address: joel.greffier@chu-nimes.fr.
authors: J
authors: J
authors: Greffier
authors: Department of Radiology, University Hospital Center of Nîmes, EA 2415, Bd Prof Robert-Debré, 30029 Nîmes cedex, France.
authors: F
authors: F
authors: Macri
authors: Department of Radiology, University Hospital Center of Nîmes, EA 2415, Bd Prof Robert-Debré, 30029 Nîmes cedex, France.
authors: A
authors: A
authors: Larbi
authors: Department of Radiology, University Hospital Center of Nîmes, EA 2415, Bd Prof Robert-Debré, 30029 Nîmes cedex, France.
authors: A
authors: A
authors: Fernandez
authors: Department of Radiology, University Hospital Center of Nîmes, EA 2415, Bd Prof Robert-Debré, 30029 Nîmes cedex, France; Dana-Farber Cancer Institute, Harvard Medical School, Boston, USA.
authors: E
authors: E
authors: Khasanova
authors: Department of Radiology, University Hospital Center of Nîmes, EA 2415, Bd Prof Robert-Debré, 30029 Nîmes cedex, France.
authors: F
authors: F
authors: Pereira
authors: Department of Radiology, University Hospital Center of Nîmes, EA 2415, Bd Prof Robert-Debré, 30029 Nîmes cedex, France; Harvard Medical School, Massachusetts General Hospital, Department of Radiology, Martinos Center for Biomedical Imaging, Boston, USA.
authors: C
authors: C
authors: Mekkaoui
authors: Department of Radiology, University Hospital Center of Nîmes, EA 2415, Bd Prof Robert-Debré, 30029 Nîmes cedex, France.
authors: J P
authors: JP
authors: Beregi
mesh_terms: D002985:Clinical Protocols; D006801:Humans; D007091:Image Processing, Computer-Assisted; D061330:Multidetector Computed Tomography / Q000592:standards*; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D012984:Software
keywords: Dose reduction; Image quality; Iterative reconstruction; Multidetector CT; Patient safety