title: Effect of Noise-Optimized Monoenergetic Postprocessing on Diagnostic Accuracy for Detecting Incidental Pulmonary Embolism in Portal-Venous Phase Dual-Energy Computed Tomography.
abstract: The aim of this study was to evaluate the diagnostic accuracy of virtual monoenergetic images (MEI+) at low kiloelectronvolt levels for the detection of incidental pulmonary embolism (PE) in oncological follow-up portal-venous phase dual-energy (DE-CTpv) staging.
  
  
  
  Twenty-six patients with incidental PE in DE-CTpv staging, which was confirmed by computed tomography pulmonary angiography (CTPA), were included in this study. In addition, 26 matched control patients who were negative for PE in both DE-CTpv and CTPA were included. All examinations were performed on a third-generation DE-CT system in single-energy (CTPA) and dual-energy mode (DE-CTpv). Subsequently, 2 series of MEI+ data sets were reconstructed at 40 and 55 keV from the DE-CTpv data and compared with CTPA and the linearly blended CTpv images. Diagnostic accuracy and diagnostic confidence were calculated and compared for MEI+ reconstructions and for CTpv images regarding the detection of PE with CTPA as standard of reference.
  
  
  
  In 3 patients, PE was only detectable in CTPA and in the 40-kV and 55-kV MEI+ reconstructions but not in CTpv images. Diagnostic accuracy increased significantly for both MEI+ series (40 keV; area under the curve [AUC], 0.928; 95% confidence interval [CI], 0.879-0.978; 55 keV; AUC, 0.960; 95% CI, 0.922-0.998) as compared with CTpv (AUC, 0.814; 95% CI, 0.741-0.887; P ≤ 0.004). Diagnostic confidence was rated highest in CTPA (median, 5; range, 3-5) followed by 55-keV MEI+ and 40-keV MEI+ (median, 5; range, 2-5 and median, 5; range, 2-5, respectively) and was lowest for CTpv (median, 4; range, 1-5), with significant differences to CTPA and MEI+ reconstructions (P ≤ 0.001).
  
  
  
  Monoenergetic image reconstructions from DE-CT data sets at low kiloelectronvolt levels improve diagnostic accuracy for the detection of incidental PE in oncological follow-up DE-CTpv staging, with the highest subjective diagnostic confidence in MEI+ at 55 keV.
authors.affiliation: From the Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tübingen, Tübingen, Germany.
authors.forename: Jakob
authors.initials: J
authors.lastname: Weiss
authors.forename: Mike
authors.initials: M
authors.lastname: Notohamiprodjo
authors.forename: Malte
authors.initials: M
authors.lastname: Bongers
authors.forename: Christoph
authors.initials: C
authors.lastname: Schabel
authors.forename: Stefanie
authors.initials: S
authors.lastname: Mangold
authors.forename: Konstantin
authors.initials: K
authors.lastname: Nikolaou
authors.forename: Fabian
authors.initials: F
authors.lastname: Bamberg
authors.forename: Ahmed E
authors.initials: AE
authors.lastname: Othman
mesh_terms: D000072226:Computed Tomography Angiography; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D009622:Noise; D011169:Portal Vein / Q000000981:diagnostic imaging / Q000503:physiopathology; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015900:Radiography, Dual-Energy Scanned Projection; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed / Q000379:methods*