LAUSR

OBJECTIVE Imaging softwares have become critical tools in the diagnosis and decision making for the treatment of abdominal aortic aneurysms (AAA). However, the inter-observer reproducibility of maximum cross-section diameter is poor. This study aimed to present and assess the quality of a new fully automated software (PRAEVAorta) that enables fast and robust detection of the aortic lumen and the infra-renal AAA characteristics including the presence of thrombus. METHODS To evaluate the segmentation obtained with this new software, we performed a quantitative comparison with the results obtained from a semi-automatic segmentation manually corrected by a senior and a junior surgeon on a dataset of 100 pre-operative CTAs from patients with infrarenal AAAs (i.e. 13465 slices). The Dice Similarity Coefficient (DSC), Jaccard index (JAC), Sensitivity, Specificity, volumetric similarity (VS), Hausdorff distance (HD), maximum aortic transverse diameter, and the duration of segmentation were calculated between the two methods and, for the semi-automatic software, also between the two observers. RESULTS The analyses demonstrated an excellent correlation of the volumes, surfaces, and diameters measured with the fully automatic and manually corrected segmentation methods, with a Pearson's coefficient correlation >0.90, P<0.0001. Overall, comparison between the fully automatic and manually corrected segmentation method by the senior surgeon revealed a mean DSC of 0.95±0.01, JAC of 0.91±0.02, sensitivity of 0.94±0.02, specificity of 0.97±0.01, VS of 0.98±0.01, and mean HD/slice of 4.61±7.26mm. The mean VS reached 0.95±0.04 for the lumen and 0.91±0.07 for the thrombus. For the fully automatic method, the segmentation time varied from 27 seconds to 4 minutes per patient vs 5 minutes to 80 minutes for the manually corrected methods (P<0.0001). CONCLUSION By enabling a fast and fully automated detailed analysis of the anatomic characteristics of infra-renal AAAs, this software could have strong applications in daily clinical practice and clinical research.