title: A noise-optimized virtual monochromatic reconstruction algorithm improves stent visualization and diagnostic accuracy for detection of in-stent re-stenosis in lower extremity run-off CT angiography.
abstract: OBJECTIVE
  To evaluate the impact of noise-optimized virtual monochromatic imaging (VMI+) on stent visualization and accuracy for in-stent re-stenosis at lower extremity dual-energy CT angiography (DE-CTA).
  
  
  METHODS
  We evaluated third-generation dual-source DE-CTA studies in 31 patients with prior stent placement. Images were reconstructed with linear blending (F_0.5) and VMI+ at 40-150 keV. In-stent luminal diameter was measured and contrast-to-noise ratio (CNR) calculated. Diagnostic confidence was determined using a five-point scale. In 21 patients with invasive catheter angiography, accuracy for significant re-stenosis (≥50 %) was assessed at F_0.5 and 80 keV-VMI+ chosen as the optimal energy level based on image-quality analysis.
  
  
  RESULTS
  At CTA, 45 stents were present. DSA was available for 28 stents whereas 12 stents showed significant re-stenosis. CNR was significantly higher with ≤80 keV-VMI+ (17.9 ± 6.4-33.7 ± 12.3) compared to F_0.5 (16.9 ± 4.8; all p < 0.0463); luminal stent diameters were increased at ≥70 keV (5.41 ± 1.8-5.92 ± 1.7 vs. 5.27 ± 1.8, all p < 0.001) and diagnostic confidence was highest at 70-80 keV-VMI+ (4.90 ± 0.48-4.88 ± 0.63 vs. 4.60 ± 0.66, p = 0.001, 0.0042). Sensitivity, negative predictive value and accuracy for re-stenosis were higher with 80 keV-VMI+ (100, 100, 96.4 %) than F_0.5 (90.9, 94.1, 89.3 %).
  
  
  CONCLUSIONS
  80 keV-VMI+ improves image quality, diagnostic confidence and accuracy for stent evaluation at lower extremity DE-CTA.
  
  
  CONCLUSIONS
  • The impact of noise-optimized virtual monochromatic imaging on stent visualization was assessed. • Virtual monochromatic imaging significantly improves stent lumen visualization and diagnostic confidence. • At 80 keV diagnostic performance for detection of in-stent restenosis was increased. • 80 keV virtual monochromatic images are recommended for stent evaluation of lower extremity vasculature.
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA.|Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Mangold
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA.
authors.forename: Carlo N
authors.initials: CN
authors.lastname: De Cecco
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA. schoepf@musc.edu.|Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC, USA. schoepf@musc.edu.
authors.forename: U Joseph
authors.initials: UJ
authors.lastname: Schoepf
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA.
authors.forename: Ricardo T
authors.initials: RT
authors.lastname: Yamada
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA.
authors.forename: Akos
authors.initials: A
authors.lastname: Varga-Szemes
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Stubenrauch
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA.|Department of Radiological Sciences, Oncology and Pathology, University of Rome "Sapienza", Rome, Italy.
authors.forename: Damiano
authors.initials: D
authors.lastname: Caruso
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Fuller
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA.|Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Vogl
authors.affiliation: Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen, Germany.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Nikolaou
authors.affiliation: Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Todoran
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA.|Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany.
authors.forename: Julian L
authors.initials: JL
authors.lastname: Wichmann
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D000072226:Computed Tomography Angiography / Q000379:methods*; D005260:Female; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging*; D006801:Humans; D007511:Ischemia / Q000000981:diagnostic imaging / Q000628:therapy; D035002:Lower Extremity / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D059629:Signal-To-Noise Ratio; D015607:Stents
keywords: CT angiography; Diagnostic accuracy; Dual-energy; Stent visualization; Virtual monochromatic imaging