title: Reduced-dose abdominopelvic CT using hybrid iterative reconstruction in suspected left-sided colonic diverticulitis.
abstract: OBJECTIVE
  To assess the effect of hybrid iterative reconstruction (HIR) and filtered back projection (FBP) on abdominopelvic CT with reduced-dose (RD-APCT) in the evaluation of acute left-sided colonic diverticulitis (ALCD).
  
  
  METHODS
  Twenty-five consecutive patients with suspected ALCD who underwent RD-APCT (mean CTDIvol 11.2 ± 4.2 mGy) were enrolled in this study. Raw data were reconstructed using FBP and two increasing HIR levels, L4 & L6. Two radiologists assessed image quality, image noise and reviewer confidence in interpreting findings of ALCD, including wall thickening, pericolic fat inflammation, pericolic abscess, and contained or free extraluminal air. Objective image noise (OIN) was measured.
  
  
  RESULTS
  OIN was reduced up to 54 % with HIR compared to FBP. Subjective image quality of HIR images was superior to FBP; subjective image noise was reduced. The detection rate of extraluminal air was higher with HIR L6. Reviewer confidence in interpreting CT findings of ALCD significantly improved with application of HIR.
  
  
  CONCLUSIONS
  RD-APCT with HIR offers superior image quality and lower image noise compared to FBP, allowing a high level of reviewer confidence in interpreting CT findings in ALCD. HIR facilitates detection of ALCD findings that may be missed with the FBP algorithm.
  
  
  CONCLUSIONS
  HIR significantly reduces objective image noise in comparison to conventional FBP. HIR offers superior subjective image quality in comparison to conventional FBP. HIR allows reduced-dose abdominopelvic CT with acceptable image quality. Reviewer confidence in interpreting CT findings in ALCD significantly improves with HIR.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany. a.laqmani@uke.de.
authors.forename: Azien
authors.initials: A
authors.lastname: Laqmani
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Veldhoen
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Dulz
authors.affiliation: Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Derlin
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.
authors.forename: Cyrus
authors.initials: C
authors.lastname: Behzadi
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.
authors.forename: Jakob
authors.initials: J
authors.lastname: Schmidt-Holtz
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.
authors.forename: Felicia
authors.initials: F
authors.lastname: Wassenberg
authors.affiliation: Department of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Sehner
authors.affiliation: Scientific and Application-oriented Studies and Consulting in Radiology (SASCRAD), Fritz-Reuter-Weg 5f, 21244, Buchholz, Germany.
authors.forename: Hans-Dieter
authors.initials: HD
authors.lastname: Nagel
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Adam
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Regier
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D004239:Diverticulitis, Colonic / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Abdominopelvic CT; Hybrid iterative reconstruction; Image noise; Left-sided colonic diverticulitis; Reduced radiation dose