title: Contrast agent and radiation dose reduction in abdominal CT by a combination of low tube voltage and advanced image reconstruction algorithms.
abstract: OBJECTIVE
  To assess image quality in abdominal CT at low tube voltage combined with two types of iterative reconstruction (IR) at four reduced contrast agent dose levels.
  
  
  METHODS
  Minipigs were scanned with standard 320 mg I/mL contrast concentration at 120 kVp, and with reduced formulations of 120, 170, 220 and 270 mg I/mL at 80 kVp with IR. Image quality was assessed by CT value, dose normalized contrast and signal to noise ratio (CNRD and SNRD) in the arterial and venous phases. Qualitative analysis was included by expert reading.
  
  
  RESULTS
  Protocols with 170 mg I/mL or higher showed equal or superior CT values: aorta (278-468 HU versus 314 HU); portal vein (205-273 HU versus 208 HU); liver parenchyma (122-146 HU versus 115 HU). In the aorta, all 170 mg I/mL protocols or higher yielded equal or superior CNRD (15.0-28.0 versus 13.7). In liver parenchyma, all study protocols resulted in higher SNRDs. Radiation dose could be reduced from standard CTDIvol = 7.8 mGy (6.2 mSv) to 7.6 mGy (5.2 mSv) with 170 mg I/mL.
  
  
  CONCLUSIONS
  Combining 80 kVp with IR allows at least a 47 % contrast agent dose reduction and 16 % radiation dose reduction for images of comparable quality.
  
  
  CONCLUSIONS
  • There is a balance between image quality, contrast dose and radiation dose. • Iterative reconstruction has a major, positive impact on this balance. • Both contrast dose and radiation dose can be reduced in abdominal CT. • The trade-off can be quantitatively described by a 3D model. • Contrast and radiation dose can be tailored according to specific safety concerns.
authors.affiliation: Department of Radiology, Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090, Brussels, Belgium, Nico.Buls@uzbrussel.be.
authors.forename: Nico
authors.initials: N
authors.lastname: Buls
authors.forename: Gert
authors.initials: G
authors.lastname: Van Gompel
authors.forename: Toon
authors.initials: T
authors.lastname: Van Cauteren
authors.forename: Koenraad
authors.initials: K
authors.lastname: Nieboer
authors.forename: Inneke
authors.initials: I
authors.lastname: Willekens
authors.forename: Guy
authors.initials: G
authors.lastname: Verfaillie
authors.forename: Paul
authors.initials: P
authors.lastname: Evans
authors.forename: Sven
authors.initials: S
authors.lastname: Macholl
authors.forename: Ben
authors.initials: B
authors.lastname: Newton
authors.forename: Johan
authors.initials: J
authors.lastname: de Mey
mesh_terms: D000465:Algorithms; D000818:Animals; D003287:Contrast Media; D005260:Female; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011833:Radiation Injuries, Experimental / Q000517:prevention & control*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D011860:Radiography, Abdominal / Q000379:methods*; D013552:Swine; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media