title: CT pulmonary angiography: simultaneous low-pitch dual-source acquisition mode with 70 kVp and 40 ml of contrast medium and comparison with high-pitch spiral dual-source acquisition with automated tube potential selection.
abstract: OBJECTIVE
  To assess the feasibility of a 70-kVp CT pulmonary angiography (CTPA) protocol using simultaneous dual-source (SimDS) acquisition mode with 40 ml of contrast medium (CM) and comparison with a high-pitch spiral dual-source (SpiralDS) acquisition protocol with automated tube potential selection (ATPS).
  
  
  METHODS
  Following the introduction of a new 70-kVp/40-ml SimDS-CTPA protocol in December 2014 for all patients with a body mass index (BMI) below 35 kg m(-2), the first 35 patients were retrospectively included in this study and assigned to Group A (BMI: 27 ± 4 kg m(-2), age: 66 ± 15 years). The last 35 patients with a BMI below 35 kg m(-2) who had received SpiralDS-CTPA with ATPS were included for comparison (Group B) (70 ml CM; BMI: 27 ± 4 kg m(-2), age: 68 ± 16 years). Subjective image quality (image quality) was assessed by two radiologists (from 1, non-diagnostic, to 4, excellent). Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), volumetric CT dose index (CTDIvol), dose-length product (DLP) and effective dose were assessed.
  
  
  RESULTS
  All examinations were of diagnostic image quality. Subjective image quality, SNR and CNR were comparable between Groups A and B (3.7 ± 0.6 vs 3.7 ± 0.5, 14.6 ± 6.0 vs 13.9 ± 3.7 and 12.4 ± 5.7 vs 11.6 ± 3.3, respectively; p > 0.05). CTDIvol, DLP and effective dose were significantly lower in Group A than in Group B (4.5 ± 1.6 vs 7.5 ± 2.1 mGy, 143.3 ± 44.8 vs 278.3 ± 79.44 mGy cm and 2.0 ± 0.6 vs 3.9 ± 1.1 mSv, respectively; p < 0.05).
  
  
  CONCLUSIONS
  70-kVp SimDS-CTPA with 40 ml of CM is feasible and provides diagnostic image quality, while radiation dose and CM can be reduced by almost 50% and 40%, respectively, compared with a SpiralDS-CTPA protocol with ATPS.
  
  
  CONCLUSIONS
  70-kVp SimDS-CTPA with 40 ml of CM is feasible in patients with a BMI up to 35 kg m(-2) and can help reduce radiation exposure and CM in these patients.
authors.affiliation: Medical Faculty, Department of Diagnostic and Interventional Radiology, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Boos
authors.affiliation: Medical Faculty, Department of Diagnostic and Interventional Radiology, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Patric
authors.initials: P
authors.lastname: Kröpil
authors.affiliation: Medical Faculty, Department of Diagnostic and Interventional Radiology, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Rotem S
authors.initials: RS
authors.lastname: Lanzman
authors.affiliation: Medical Faculty, Department of Diagnostic and Interventional Radiology, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Joel
authors.initials: J
authors.lastname: Aissa
authors.affiliation: Medical Faculty, Department of Diagnostic and Interventional Radiology, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Schleich
authors.affiliation: Medical Faculty, Department of Diagnostic and Interventional Radiology, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Heusch
authors.affiliation: Medical Faculty, Department of Diagnostic and Interventional Radiology, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Lino M
authors.initials: LM
authors.lastname: Sawicki
authors.affiliation: Medical Faculty, Department of Diagnostic and Interventional Radiology, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Gerald
authors.initials: G
authors.lastname: Antoch
authors.affiliation: Medical Faculty, Department of Diagnostic and Interventional Radiology, University Dusseldorf, Dusseldorf, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Thomas
mesh_terms: D000368:Aged; D000072226:Computed Tomography Angiography / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D000069079:Radiation Exposure / Q000032:analysis* / Q000517:prevention & control*; D011835:Radiation Protection / Q000379:methods; D011856:Radiographic Image Enhancement / Q000379:methods; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media