MDCT interpretation of the ascending aorta with semiautomated measurement software: Improved reproducibility compared with manual techniques

BackgroundTreatment decisions for ascending aortic aneurysms are guided by measurements from CT angiograms.ObjectiveThe aim was to evaluate the reproducibility of these measurements by using manual techniques and advanced imaging software.MethodsTwo radiologists measured maximal ascending aorta diameter on CT angiograms in 30 subjects at 4 separate reading sessions-2 with manual techniques and 2 with semiautomated software analysis. Interobserver and intraobserver variabilities were assessed with Bland-Altman plots and Spearman correlation coefficients.ResultsInterobserver variability was smaller for the software-assisted method. Limits of agreement for the manual method were −4.2 mm and 9.2 mm compared with −4.0 mm and 4.6 mm for the software-assisted method; coefficients of repeatability were 6.8 mm and 4.3 mm. Intraobserver variability was inconsistent between readers. Strong correlation was found between observers who used both methods (R2 = 0.8078-0.9881; P < .05 for all).ConclusionThe use of an advanced imaging software for measurement of ascending aortic aneurysm reduces interobserver variability.