Purpose Three-Dimensional (3D) guidance has not been widely adopted in interventional neuro-radiology (INR) despite the recognized role of 3D imaging for diagnostic and therapeutic purposes. The objective of the study was to describe our experience using a new bi-plane 3D guidance software (Vessel ASSIST, GE Healthcare) for INR procedures and identify a subset of procedures which would benefit the most from it.

Material and methods Between Mar-2017 and Feb-2018 bi-plane 3D guidance was made available for INR procedures, in addition to conventional 2D roadmap. The decision to use 3D guidance was based on anticipated procedure difficulty and availability of pre-operative images. For brain aneurysms and arteriovenous pathologies, diagnostic trans-arterial catheter injected 3D acquisition was used to segment vessels or structures of interest, which were then overlaid on top of fluoroscopy on the frontal and lateral plane with automatic registration. For transvenous procedures, vessels of interest were first segmented using the time of flight sequence of a pre-operative magnetic resonance venogram (MRV). Two non-contrast fluoroscopic frames of the skull on each plane were used to register the MRV with fluoroscopy before venous access. After bi-plane 3D guidance was used, an operator filled questionnaire recorded: 1- feasibility of the technique in terms of timing and accuracy, 2- perceived benefits of the technique compared to conventional 2D guidance, and 3- if fusion on both planes had been used.

Results Guidance using an intra-operative 3D acquisition or pre-operative MRV was reported feasible and appropriately accurate in all cases with both automatic and semi-automatic registration. Fusion on both planes was used in 30 cases. More specifically, guidance using intra-operative 3D acquisition was reported superior to conventional 2D roadmapping for complex aneurysm coiling and arteriovenous fistula (AVF) embolization. Use of pre-operative MRV 3D guidance was reported useful for trasnvenous access for embolization of AVF and for venous sinus stenting (VSS) procedures, providing visibility of the cortical veins without need for arterial injection. Operators reported better anatomical path visualization, increased confidence in approaching the lesion and increased confidence during the treatment, compared to 2D visualization alone.

Conclusion Bi-plane 3D guidance using either pre-operative or per-operative images is feasible and safe for procedures such as complex aneurysm, AVF and VSS. Further studies should quantify the benefits on procedure time, radiation dose, contrast media and operator confidence.

Disclosures A. Santillan: None. J. Schwarz: None. G. Avignon: 5; C; General Electric. P. Ozbek: 5; C; General Electric. A. Patsalides: None.