title: Prospective respiratory-triggered 64-slice CT pulmonary angiography for detection of pulmonary embolism--a feasibility study in a porcine model.
abstract: The objective of this study is to investigate the feasibility of prospectively respiratory-triggered CT pulmonary angiography (CTPA) for detection of pulmonary embolism (PE) in a porcine model. A free-breathing respiratory-triggered multislice CTPA (120 kV, 140 mAs(eff), 2.5-mm slice thickness) and two CTPA in breath-hold technique (120 kV, 140 mAs(eff.) and 250mAs(eff), 1-mm and 3-mm image reconstruction) were performed in six pigs with pulmonary embolism. Diagnostic accuracy was computed, and differences in detection rates between both techniques were assessed on a per-embolus basis with the Wilcoxon test. Thin-sliced 1-mm images, acquired with 250mAs(eff), served as the standard of reference. Respiratory-triggered CTPA reached high diagnostic accuracy in detection of lobar and segmental PE equal to the results with the breath-hold technique (p > 0.05). For detection of subsegmental emboli, standard breath-hold techniques performed significantly better than respiratory-gated CTPA (sensitivity, 68.3% versus 24.4%; p < 0.05). Free-breathing respiratory-triggered CTPA is feasible for detection of lobar and segmental PE, with diagnostic accuracy equivalent to that of a standard CTPA in breath-hold. Although this technique is not recommended for assessment of emboli in the subsegmental vasculature, prospective respiratory-triggered CTPA may be of added value in patients who cannot hold their breath appropriately for CTPA scanning.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany. f.henes@uke.uni-hamburg.de
authors.forename: Frank Oliver G
authors.initials: FO
authors.lastname: Henes
authors.forename: Michael
authors.initials: M
authors.lastname: Groth
authors.forename: Marc
authors.initials: M
authors.lastname: Regier
authors.forename: Thorsten
authors.initials: T
authors.lastname: Bley
authors.forename: Hans-Dieter
authors.initials: HD
authors.lastname: Nagel
authors.forename: Gerhard
authors.initials: G
authors.lastname: Adam
authors.forename: Philipp G C
authors.initials: PG
authors.lastname: Begemann
mesh_terms: D000792:Angiography / Q000379:methods*; D000818:Animals; D005240:Feasibility Studies; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D011857:Radiographic Image Interpretation, Computer-Assisted; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013552:Swine; D014057:Tomography, X-Ray Computed / Q000379:methods*