title: Attenuation-based kV pair selection in dual source dual energy computed tomography angiography of the chest: impact on radiation dose and image quality.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the impact of attenuation-based kilovoltage (kV) pair selection in dual source dual energy (DSDE)-pulmonary embolism (PE) protocol examinations on radiation dose savings and image quality.
  
  
  METHODS
  A prospective study was carried out on 118 patients with suspected PE. In patients in whom attenuation-based kV pair selection selected the 80/140Sn kV pair, the pre-scan 100/140Sn CTDIvol (computed tomography dose index volume) values were compared with the pre-scan 80/140Sn CTDIvol values. Subjective and objective image quality parameters were assessed.
  
  
  RESULTS
  Attenuation-based kV pair selection switched to the 80/140Sn kV pair ("switched" cohort) in 63 out of 118 patients (53%). The mean 100/140Sn pre-scan CTDIvol was 8.8 mGy, while the mean 80/140Sn pre-scan CTDIvol was 7.5 mGy. The average estimated dose reduction for the "switched" cohort was 1.3 mGy (95% CI 1.2, 1.4; p < 0.001), representing a 15% reduction in dose. After adjusting for patient weight, mean attenuation was significantly higher in the "switched" vs. "non-switched" cohorts in all five pulmonary arteries and in all lobes on iodine maps.
  
  
  CONCLUSIONS
  This study demonstrates that attenuation-based kV pair selection in DSDE examination is feasible and can offer radiation dose reduction without compromising image quality.
  
  
  CONCLUSIONS
  • Attenuation-based kV pair selection in dual energy examination is feasible. • It can offer radiation dose reduction to approximately 50% of patients. • Approximate 15% reduction in radiation dose was achieved using this technique. • The image quality is not compromised by use of attenuation-based kV pair selection.
authors.affiliation: Thoracic Imaging, L10, Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA. renapur@ccf.org.
authors.forename: Rahul D
authors.initials: RD
authors.lastname: Renapurkar
authors.affiliation: Siemens Medical Solutions, Malvern, PA, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Primak
authors.affiliation: Thoracic Imaging, L10, Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Azok
authors.affiliation: Thoracic Imaging, L10, Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Lempel
authors.affiliation: Department of Radiology, Case Western Reserve University-Metro Health Medical Center, Cleveland, OH, 44109, USA.
authors.forename: Yasmeen
authors.initials: Y
authors.lastname: Tandon
authors.affiliation: Quantitative Health Sciences, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Bullen
authors.affiliation: Section of Medical Physics, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: Dong
authors.affiliation: Thoracic Imaging, L10, Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
authors.forename: Wadih
authors.initials: W
authors.lastname: Karim
authors.affiliation: Thoracic Imaging, L10, Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
authors.forename: Ruffin
authors.initials: R
authors.lastname: Graham
mesh_terms: D000328:Adult; D000368:Aged; D001835:Body Weight; D000072226:Computed Tomography Angiography / Q000379:methods* / Q000592:standards*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000000981:diagnostic imaging; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D013902:Radiography, Thoracic / Q000379:methods* / Q000592:standards*
keywords: Attenuation; CARE kV; CT angiography; Dual energy CT; Pulmonary embolism