title: Advanced modelled iterative reconstruction for abdominal CT: qualitative and quantitative evaluation.
abstract: OBJECTIVE
  To determine qualitative and quantitative image-quality parameters in abdominal imaging using advanced modelled iterative reconstruction (ADMIRE) with third-generation dual-source 192 section CT.
  
  
  METHODS
  Forty patients undergoing abdominal portal-venous CT at different tube voltage levels (90, 100, 110, and 120 kVp, n = 10 each) and 10 consecutive patients undergoing abdominal non-enhanced low-dose CT (100 kVp, 60 mAs) using a third-generation dual-source 192 section CT machine in the single-source mode were included. Images were reconstructed with filtered back projection (FBP) and ADMIRE (strength levels 1-5). Two blinded, independent readers subjectively determined image noise, artefacts, visibility of small structures, and image contrast, and measured attenuation in the liver, spleen, kidney, muscle, fat, and urinary bladder, and objective image noise.
  
  
  RESULTS
  Subjective noise was significantly lower and image contrast significantly higher for each increasing ADMIRE strength level and also for ADMIRE 1 compared to FBP (all, p < 0.001). No significant differences were found for artefact and visibility ratings among image sets (all, p > 0.05). Attenuation was similar across tube voltage-image datasets in all anatomical regions (all, p > 0.05). Objective noise was significantly lower for each increasing ADMIRE strength level, and for ADMIRE 1 compared to FBP (all, p < 0.001, maximal reduction 53%). Independent predictors of noise were tube voltage (p < 0.05) and current (p < 0.001), diameter (p < 0.05), and reconstruction algorithm (p<0.001); the amount of noise reduction was related only to the reconstruction algorithm (p < 0.001).
  
  
  CONCLUSIONS
  Abdominal CT using ADMIRE results in an improved image quality with lower image noise as compared with FBP, while the attenuation of various anatomical regions remains constant among reconstruction algorithms.
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Gordic
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Switzerland; Division of Radiology and Nuclear Medicine, Kantonsspital St Gallen, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Desbiolles
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Stolzmann
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Gantner
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Switzerland; Division of Radiology and Nuclear Medicine, Kantonsspital St Gallen, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Leschka
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Switzerland.
authors.forename: D B
authors.initials: DB
authors.lastname: Husarik
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Switzerland. Electronic address: hatem.alkadhi@usz.ch.
authors.forename: H
authors.initials: H
authors.lastname: Alkadhi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003287:Contrast Media; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D011860:Radiography, Abdominal / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide