title: Dual-Energy CTA in Patients with Symptomatic Peripheral Arterial Occlusive Disease: Study of Diagnostic Accuracy and Impeding Factors.
abstract: PurposeThe purpose of this study was to assess the diagnostic performance of dual-energy CT angiography (DE-CTA) in patients with symptomatic peripheral artery occlusive disease (PAOD) and to identify factors that impede its diagnostic accuracy.Materials and MethodsDual-source DE-CTA scans of the lower extremities of 94 patients were retrospectively compared to the diagnostic reference standard, digital subtraction angiography (DSA). Two independent observers assessed PAOD incidence, image quality, artifacts, and diagnostic accuracy of DE-CTA in 1014 arterial segments on axial, combined 80/140 kVp reconstructions and on 3 D maximum intensity projections (MIP) after automated bone and plaque removal. The impact of calcifications, image quality, and image artifacts on the diagnostic accuracy was evaluated using Fisher's exact test. Furthermore, interobserver agreement was analyzed.ResultsTwo observers achieved sensitivities of 98.0 % and 93.9 %, respectively, and specificities of 75.0 % and 66.7 %, respectively, for detecting stenoses of > 50 % of the lower extremity arteries. Calcifications impeded specificity, e. g. from 81.2 % to 46.2 % for reader 1 (p < 0.001). Specificity increased with higher image quality, e. g. from 70.0 % to 76.4 % for reader 1 (p < 0.001). Artifacts decreased the specificity of reader 2 (p < 0.001). The overall interobserver agreement ranged between moderate and substantial for stenosis detection and calcified plaques.ConclusionDE-CTA is accurate in the detection of arterial stenoses of > 50 % in symptomatic PAOD patients. Calcified atherosclerotic plaques, image quality, and artifacts may impede specificity.Key Points:· Sensitivities of DE-CTA were 98.0 and 93.9 %, specificities 75.0 % and 66.7 %.. · Interobserver agreement was moderate to substantial for stenosis and plaque detection.. · Calcified atherosclerotic plaques, image quality, and artifacts may impede specificity..Citation Format· Klink T, Wilhelm T, Roth C et al. Dual-Energy CTA in Patients with Symptomatic Peripheral Arterial Occlusive Disease: Study of Diagnostic Accuracy and Impeding Factors. Fortschr Röntgenstr 2017; 189: 441 - 452.
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University of Würzburg, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Klink
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Giessen and Marburg, Campus Marburg, Germany.
authors.forename: Theresa
authors.initials: T
authors.lastname: Wilhelm
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Giessen and Marburg, Campus Marburg, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Roth
authors.affiliation: University Institute of Diagnostic, Interventional, and Pediatric Radiology, Inselspital - University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Johannes T
authors.initials: JT
authors.lastname: Heverhagen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging*; D016477:Artifacts; D000072226:Computed Tomography Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D058729:Peripheral Arterial Disease / Q000000981:diagnostic imaging*; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity