title: Reducing Radiation Dose at Chest CT: Comparison Among Model-based Type Iterative Reconstruction, Hybrid Iterative Reconstruction, and Filtered Back Projection.
abstract: The study aimed to evaluate the performances of two iterative reconstruction (IR) algorithms and of filtered back projection (FBP) when using reduced-dose chest computed tomography (RDCT) compared to standard-of-care CT.
  
  
  
  An institutional review board approval was obtained. Thirty-six patients with hematologic malignancies referred for a control chest CT of a known lung disease were prospectively enrolled. Patients underwent standard-of-care scan reconstructed with hybrid IR, followed by an RDCT reconstructed with FBP, hybrid IR, and iterative model reconstruction. Objective and subjective quality measurements, lesion detectability, and evolution assessment on RDCT were recorded.
  
  
  
  For RDCT, the CTDIvol (volumetric computed tomography dose index) was 0.43 mGy⋅cm for all patients, and the median [interquartile range] effective dose was 0.22 mSv [0.22-0.24]; corresponding measurements for standard-of-care scan were 3.4 mGy [3.1-3.9] and 1.8 mSv [1.6-2.0]. Noise significantly decreased from FBP to hybrid IR and from hybrid IR to iterative model reconstruction on RDCT, whereas lesion conspicuity and diagnostic confidence increased. Accurate evolution assessment was obtained in all cases with IR. Emphysema identification was higher with iterative model reconstruction.
  
  
  
  Although iterative model reconstruction offered better diagnostic confidence and emphysema detection, both IR algorithms allowed an accurate evolution assessment with an effective dose of 0.22 mSv.
authors.affiliation: Department of Radiology, INSERM UMR_S1165, University Paris Diderot, Sorbonne Paris-Cité, AP-HP, Saint Louis Hospital, 1 avenue Claude Vellefaux, 75 010 Paris, France. Electronic address: constancedemm@gmail.com.
authors.forename: Constance
authors.initials: C
authors.lastname: de Margerie-Mellon
authors.affiliation: Department of Radiology, INSERM UMR_S1165, University Paris Diderot, Sorbonne Paris-Cité, AP-HP, Saint Louis Hospital, 1 avenue Claude Vellefaux, 75 010 Paris, France.
authors.forename: Cédric
authors.initials: C
authors.lastname: de Bazelaire
authors.affiliation: Department of Informatics and Biostatistics, University Paris Diderot, Sorbonne Paris-Cité, AP-HP, Saint Louis Hospital, 1 avenue Claude Vellefaux, 75 010 Paris, France; INSERM, ECSTRA team, CRESS-UMR_S 1153, 75010 Paris, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Montlahuc
authors.affiliation: Department of Informatics and Biostatistics, University Paris Diderot, Sorbonne Paris-Cité, AP-HP, Saint Louis Hospital, 1 avenue Claude Vellefaux, 75 010 Paris, France; INSERM, ECSTRA team, CRESS-UMR_S 1153, 75010 Paris, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Lambert
authors.affiliation: Department of Nuclear Medicine, University Paris Diderot, Sorbonne Paris-Cité, AP-HP, Saint Louis Hospital, 1 avenue Claude Vellefaux, 75 010 Paris, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Martineau
authors.affiliation: Philips Healthcare, 33 rue de Verdun, 92156 Suresnes Cedex, France; Department of Radiology, Vaudois University Hospital, rue du Bugnon 46, 1011 Lausanne, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Coulon
authors.affiliation: Department of Radiology, INSERM UMR_S1165, University Paris Diderot, Sorbonne Paris-Cité, AP-HP, Saint Louis Hospital, 1 avenue Claude Vellefaux, 75 010 Paris, France.
authors.forename: Eric
authors.initials: E
authors.lastname: de Kerviler
authors.affiliation: Department of Radiology, Vaudois University Hospital, rue du Bugnon 46, 1011 Lausanne, Switzerland.
authors.forename: Catherine
authors.initials: C
authors.lastname: Beigelman
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D054893:Cone-Beam Computed Tomography / Q000379:methods; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D013902:Radiography, Thoracic / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Computed tomography; image noise; iterative reconstruction; lung; radiation dose reduction