title: Reduced Radiation Dose with Model-based Iterative Reconstruction versus Standard Dose with Adaptive Statistical Iterative Reconstruction in Abdominal CT for Diagnosis of Acute Renal Colic.
abstract: OBJECTIVE
  To evaluate the accuracy of reduced-dose abdominal computed tomographic (CT) imaging by using a new generation model-based iterative reconstruction (MBIR) to diagnose acute renal colic compared with a standard-dose abdominal CT with 50% adaptive statistical iterative reconstruction (ASIR).
  
  
  METHODS
  This institutional review board-approved prospective study included 118 patients with symptoms of acute renal colic who underwent the following two successive CT examinations: standard-dose ASIR 50% and reduced-dose MBIR. Two radiologists independently reviewed both CT examinations for presence or absence of renal calculi, differential diagnoses, and associated abnormalities. The imaging findings, radiation dose estimates, and image quality of the two CT reconstruction methods were compared. Concordance was evaluated by κ coefficient, and descriptive statistics and t test were used for statistical analysis.
  
  
  RESULTS
  Intraobserver correlation was 100% for the diagnosis of renal calculi (κ = 1). Renal calculus (τ = 98.7%; κ = 0.97) and obstructive upper urinary tract disease (τ = 98.16%; κ = 0.95) were detected, and differential or alternative diagnosis was performed (τ = 98.87% κ = 0.95). MBIR allowed a dose reduction of 84% versus standard-dose ASIR 50% (mean volume CT dose index, 1.7 mGy ± 0.8 [standard deviation] vs 10.9 mGy ± 4.6; mean size-specific dose estimate, 2.2 mGy ± 0.7 vs 13.7 mGy ± 3.9; P < .001) without a conspicuous deterioration in image quality (reduced-dose MBIR vs ASIR 50% mean scores, 3.83 ± 0.49 vs 3.92 ± 0.27, respectively; P = .32) or increase in noise (reduced-dose MBIR vs ASIR 50% mean, respectively, 18.36 HU ± 2.53 vs 17.40 HU ± 3.42). Its main drawback remains the long time required for reconstruction (mean, 40 minutes).
  
  
  CONCLUSIONS
  A reduced-dose protocol with MBIR allowed a dose reduction of 84% without increasing noise and without an conspicuous deterioration in image quality in patients suspected of having renal colic.
authors.affiliation: From the Radiology Service (M.F., A.A., R.P., L.B.), Urology Service (A.S., L.G.), {Emergency} Service (C.P.), and {Regional Management of Clinical Research and Innovation} (A.M.), Centre Hospitalier Universitaire Gabriel Montpied, 58 Rue Montalembert, 63000 Clermont-Ferrand, France.
authors.forename: Mikael
authors.initials: M
authors.lastname: Fontarensky
authors.affiliation: From the Radiology Service (M.F., A.A., R.P., L.B.), Urology Service (A.S., L.G.), {Emergency} Service (C.P.), and {Regional Management of Clinical Research and Innovation} (A.M.), Centre Hospitalier Universitaire Gabriel Montpied, 58 Rue Montalembert, 63000 Clermont-Ferrand, France.
authors.forename: Agaïcha
authors.initials: A
authors.lastname: Alfidja
authors.affiliation: From the Radiology Service (M.F., A.A., R.P., L.B.), Urology Service (A.S., L.G.), {Emergency} Service (C.P.), and {Regional Management of Clinical Research and Innovation} (A.M.), Centre Hospitalier Universitaire Gabriel Montpied, 58 Rue Montalembert, 63000 Clermont-Ferrand, France.
authors.forename: Renan
authors.initials: R
authors.lastname: Perignon
authors.affiliation: From the Radiology Service (M.F., A.A., R.P., L.B.), Urology Service (A.S., L.G.), {Emergency} Service (C.P.), and {Regional Management of Clinical Research and Innovation} (A.M.), Centre Hospitalier Universitaire Gabriel Montpied, 58 Rue Montalembert, 63000 Clermont-Ferrand, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Schoenig
authors.affiliation: From the Radiology Service (M.F., A.A., R.P., L.B.), Urology Service (A.S., L.G.), {Emergency} Service (C.P.), and {Regional Management of Clinical Research and Innovation} (A.M.), Centre Hospitalier Universitaire Gabriel Montpied, 58 Rue Montalembert, 63000 Clermont-Ferrand, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Perrier
authors.affiliation: From the Radiology Service (M.F., A.A., R.P., L.B.), Urology Service (A.S., L.G.), {Emergency} Service (C.P.), and {Regional Management of Clinical Research and Innovation} (A.M.), Centre Hospitalier Universitaire Gabriel Montpied, 58 Rue Montalembert, 63000 Clermont-Ferrand, France.
authors.forename: Aurélien
authors.initials: A
authors.lastname: Mulliez
authors.affiliation: From the Radiology Service (M.F., A.A., R.P., L.B.), Urology Service (A.S., L.G.), {Emergency} Service (C.P.), and {Regional Management of Clinical Research and Innovation} (A.M.), Centre Hospitalier Universitaire Gabriel Montpied, 58 Rue Montalembert, 63000 Clermont-Ferrand, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Guy
authors.affiliation: From the Radiology Service (M.F., A.A., R.P., L.B.), Urology Service (A.S., L.G.), {Emergency} Service (C.P.), and {Regional Management of Clinical Research and Innovation} (A.M.), Centre Hospitalier Universitaire Gabriel Montpied, 58 Rue Montalembert, 63000 Clermont-Ferrand, France.
authors.forename: Louis
authors.initials: L
authors.lastname: Boyer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011446:Prospective Studies; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D011860:Radiography, Abdominal / Q000379:methods*; D056844:Renal Colic / Q000175:diagnosis*; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000706:statistics & numerical data; D055815:Young Adult