A Comparison of Two-Dimensional CTA and Three-Dimensional Volumetric CTA Analysis Software Algorithms for Planning Thoracic, Thoracoabdominal, and Infrarenal Aortic Aneurysm Repair

Abstract

This study compared relevant measurements in two-dimensional (2D) computed tomography angiography (CTA) imaging and semiautomated algorithmic measurements using 3D Volumetric CTA Interpretation software for thoracic, thoracoabdominal, and infrarenal aortic aneurysms. This retrospective study compared data points in 20 patients who underwent standard 2D CTA imaging and 3D CTA Interpretative software imaging for aortic aneurysmal disease. Information gathered was intended for preoperative planning and potential endovascular options. Measurements taken within the 3D CTA Interpretation software was done via a point-and-click method whereby the software algorithmically determines measurements along the aorta and displays them when the region of interest is selected. The software also determines the distance between two points using a centerline through the aorta as a reference. Intraluminal surface irregularities and location of thrombus is determined by direct observation via “drive through” techniques. Standard measurements were taken to include diameter of normal artery proximal and distal, length of neck, and landing zone. Additional criteria were evaluated for all aneurysm types including the presence of a normal artery, intraluminal defects, percentage of thrombus in the neck, and degree of calcification. From the 20 patients in our cohort, we obtained 20 contemporary imaging examination pairs. Bland-Altman analysis was performed and demonstrated that the 2D and 3D mean difference measurements was 0.8 mm. All data groups fell within two standard deviations with a range of 1.96 mm. Intraluminal abnormalities and more accurate vessel wall morphology were obtained with 3D imaging. The accuracy of 3D Volumetric CTA Analysis Software Algorithms in evaluating aneurysmal aortic disease for the purpose of preoperative planning is comparable to that of 2D CTA imaging and frequently provides helpful luminal surface information in preparation of repair.