title: Submillisievert Computed Tomography of the Chest Using Model-Based Iterative Algorithm: Optimization of Tube Voltage With Regard to Patient Size.
abstract: OBJECTIVE
  The aim of this study was to define optimal tube potential for soft tissue and vessel visualization in dose-reduced chest CT protocols using model-based iterative algorithm in average and overweight patients.
  
  
  METHODS
  Thirty-six patients receiving chest CT according to 3 protocols (120 kVp/noise index [NI], 60; 100 kVp/NI, 65; 80 kVp/NI, 70) were included in this prospective study, approved by the ethics committee. Patients' physical parameters and dose descriptors were recorded. Images were reconstructed with model-based algorithm. Two radiologists evaluated image quality and lesion conspicuity; the protocols were intraindividually compared with preceding control CT reconstructed with statistical algorithm (120 kVp/NI, 20). Mean and standard deviation of attenuation of the muscle and fat tissues and signal-to-noise ratio of the aorta were measured.
  
  
  RESULTS
  Diagnostic images (lesion conspicuity, 95%-100%) were acquired in average and overweight patients at 1.34, 1.02, and 1.08 mGy and at 3.41, 3.20, and 2.88 mGy at 120, 100, and 80 kVp, respectively. Data are given as CT dose index volume values.
  
  
  CONCLUSIONS
  Model-based algorithm allows for submillisievert chest CT in average patients; the use of 100 kVp is recommended.
authors.affiliation: From the *Institute for Clinical Radiology and †Clinic for Anaesthesiology, University Hospital of Ludwig Maximilian University, Munich, Germany.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Deák
authors.forename: Friedrich
authors.initials: F
authors.lastname: Maertz
authors.forename: Felix
authors.initials: F
authors.lastname: Meurer
authors.forename: Susan
authors.initials: S
authors.lastname: Notohamiprodjo
authors.forename: Fabian
authors.initials: F
authors.lastname: Mueck
authors.forename: Lucas L
authors.initials: LL
authors.lastname: Geyer
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Stefan
authors.initials: S
authors.lastname: Wirth
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001835:Body Weight; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D050177:Overweight; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D013902:Radiography, Thoracic / Q000295:instrumentation / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*