Evaluation of real-time guidewire navigation using virtual endoscopic 4D fluoroscopy

Abstract

4D fluoroscopy is a method for real-time 3D visualization of endovascular devices using biplane fluoroscopy. Frame-byframe (15 fps) 4D reconstructions of the device are overlayed on 3D vascular anatomy derived from 3D-DSA. We describe a 4D-assisted guidance platform that provides virtual endoscopic renderings of blood vessels and report on its use for navigating guidewires in a patient-specific vascular phantom. The 4D-assisted platform provides two 4D display modes plus conventional 2D fluoroscopy. Virtual endoscopic 4D mode shows a real-time view of the guidewire tip and the downstream vessel with a viewpoint inside the vessel. Path-planning highlights the target vessel branches. External 4D display mode provides an external rotatable viewpoint of the device and vasculature. In a phantom study, operators navigated a guidewire through branches of a 3D-printed phantom. Performance was compared to navigation with 2D fluoroscopy alone. Operators rated the degree to which they used the 2D and 4D display modes on a Likert scale (1-never, 5-almost always). Quantitative imaging metrics were obtained from processed video recordings. Three users completed 15 of 15 challenges with 4D-assisted display, whereas the 2D-only guidance completion rate was 13/15. With both 2D and 4D displays available, users reported using the 2D display never-to-sometimes (median score = 2) and 4D display often or almost always (median = 5). The virtual endoscopic viewpoint was utilized more frequently than the external viewpoint. 4D fluoroscopy with virtual endoscopic display provides a new and potentially useful mode for visualization of guidewire and catheter manipulations in complex vascular anatomy.