title: Benefits of sinogram-affirmed iterative reconstruction in 0.4 mSv ultra-low-dose CT of the upper abdomen following transarterial chemoembolisation: comparison to low-dose and standard-dose CT and filtered back projection technique.
abstract: OBJECTIVE
  To evaluate the advantage of sinogram-affirmed iterative reconstruction (SIR) compared to filtered back projection (FBP) in upper abdomen computed tomography (CT) after transarterial chemoembolisation (TACE) at different tube currents.
  
  
  METHODS
  The study was approved by the institutional review board. Written informed consent was obtained from all patients. Post-TACE CT was performed with different tube currents successively varied in four steps (180, 90, 45 and 23 mAs) with 40 patients per group (mean age: 60±12 years, range: 23-85 years, sex: 70 female, 90 male). The data were reconstructed with standard FBP and five different SIR strengths. Image quality was independently rated by two readers on a five-point scale. High (Lipiodol-to-liver) as well as low (liver-to-fat) contrast-to-noise ratios (CNRs) were intra-individually compared within one dose to determine the optimal strength (S1-S5) and inter-individually between different doses to determine the possibility of dose reduction using the Kruskal-Wallis test.
  
  
  RESULTS
  Subjective image quality and objective CNR analysis were concordant: intra-individually, SIR was significantly (p<0.001) superior to FBP. Inter-individually, regarding different doses (180 versus 23 ref mAs), there was no significant (p=1.00) difference when using S5 SIR at 23 mAs instead of FBP.
  
  
  CONCLUSIONS
  SIR allows for an 88% dose reduction from 3.43 to 0.4 mSv in unenhanced CT of the liver following TACE without subjective or objective loss in image quality.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany. Electronic address: bbodelle@googlemail.com.
authors.forename: B
authors.initials: B
authors.lastname: Bodelle
authors.affiliation: Department of Diagnostic and Interventional Radiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Isler
authors.affiliation: Department of Diagnostic and Interventional Radiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
authors.forename: J-E
authors.initials: JE
authors.lastname: Scholtz
authors.affiliation: Department of Diagnostic and Interventional Radiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Frellesen
authors.affiliation: Department of Diagnostic and Interventional Radiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Luboldt
authors.affiliation: Department of Diagnostic and Interventional Radiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
authors.forename: T J
authors.initials: TJ
authors.lastname: Vogl
authors.affiliation: Department of Diagnostic and Interventional Radiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Beeres
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D016461:Chemoembolization, Therapeutic / Q000379:methods*; D004998:Ethiodized Oil / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D011860:Radiography, Abdominal / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D004998:Ethiodized Oil