Feasibility and limitations of an automated 2D-3D rigid image registration system for complex endovascular aortic procedures.

Purpose:To examine the feasibility of an automated 2-dimensional (2D) to 3- dimensional (3D) image registration system to simplify the navigational challenges faced in complex endovascular aortic procedures.Methods:An automated 2D-3D image registration system was used to overlay pre-acquired 3D computed tomography images onto fluoroscopy images taken during endovascular aneurysm repair. Errors between the 3D overlay and digital subtraction angiograms were measured and correlated with aortic neck angulation. A mean discrepancy #3 mm was considered clinically acceptable.Results:There was a strong correlation between maximum neck angulation and maximum registration error (Pearson's r50.75). Aortas with a maximum neck angulation ≤30° had a mean error of 2.5±1.2 mm, whereas aortas with neck angulation >30° had a mean error of 6.2±2.5 mm (p<0.0001).Conclusion:The major source of registration errors is aortic deformation caused by the presence of the introducer and endovascular graft. Further work is required if...