title: Improved image quality and low radiation dose with hybrid iterative reconstruction with 80 kV CT pulmonary angiography.
abstract: OBJECTIVE
  To determine the impact of hybrid iterative reconstruction (HIR) on image quality in 80 kV CT pulmonary angiography (CTPA) in comparison to filtered-back-projection (FBP).
  
  
  METHODS
  Fifty patients (body weight <80 kg) with suspected pulmonary embolism (PE) underwent CTPA at 80 kV (mean CTDIvol, 2.3 mGy; effective dose, 1.2 mSv). The raw data were reconstructed using FBP and three increasing HIR levels. Two radiologists assessed image quality and image noise. Conspicuity of PE was assessed in central, segmental, and subsegmental arteries. CT attenuation of pulmonary arteries, objective image noise (OIN) and contrast-to-noise ratios (CNR) were assessed.
  
  
  RESULTS
  With each HIR level, a significant decrease in subjective and objective image noise was achieved with a reduction of OIN up to 46% in comparison with FBP. CNR significantly increased with the application of HIR compared to FBP. Image quality was rated significantly higher at HIR reconstructions in comparison with FBP. Diagnosis of PE was feasible with each data set; however, conspicuity of central and segmental PE significantly improved with the use of HIR.
  
  
  CONCLUSIONS
  Eighty kilovoltage CTPA with HIR provides improved image quality and conspicuity of pulmonary embolism enabling low dose CTPA protocols close to 1 mSv in patients weighing less than 80 kg.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center, Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Azien
authors.initials: A
authors.lastname: Laqmani
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center, Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Regier
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center, Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Veldhoen
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center, Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Backhaus
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center, Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Felicia
authors.initials: F
authors.lastname: Wassenberg
authors.affiliation: Department of Medical Biometry and Epidemiology, University Medical Center, Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Sehner
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center, Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Groth
authors.affiliation: Scientific and Application-oriented Studies and Consulting in Radiology (SASCRAD), Fritz-Reuter-Weg 5f, 21244 Buchholz, Germany.
authors.forename: Hans-Dieter
authors.initials: HD
authors.lastname: Nagel
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center, Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Adam
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center, Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany. Electronic address: fhenes@uke.de.
authors.forename: Frank O
authors.initials: FO
authors.lastname: Henes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Computed tomography pulmonary angiography; Iterative reconstruction; Low tube voltage; Pulmonary embolism; Radiation dose