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

Background: Treatment decisions for ascending aortic aneurysms are guided by measurements from CT angiograms. Objective: The aim was to evaluate the reproducibility of these measurements by using manual techniques and advanced imaging software. Methods: Two 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. Results: Interobserver variability was smaller for the software-assisted method. Limits of agreement for the manual method were-4.2mm and 9.2mm compared with-4.0mm and 4.6mm for the software-assisted method; coefficients of repeatability were 6.8mm and 4.3mm. 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). Conclusion: The use of an advanced imaging software for measurement of ascending aortic aneurysm reduces interobserver variability.