Mixed reality for the assessment of aortoiliac anatomy in patients with abdominal aortic aneurysm prior to open and endovascular repair: Feasibility and interobserver agreement.

Objectives: The objective is to evaluate the feasibility and interobserver agreement of a Mixed Reality Viewer (MRV) in the assessment of aortoiliac vascular anatomy of abdominal aortic aneurysm (AAA) patients.

Methods: Fifty preoperative computed tomography angiographies (CTAs) of AAA patients were included. CTAs were assessed in a mixed reality (MR) environment with respect to aortoiliac anatomy according to a standardized protocol by two experienced observers (Mixed Reality Viewer, MRV, Brainlab AG, Germany). Additionally, all CTAs were independently assessed applying the same protocol by the same observers using a conventional DICOM viewer on a two-dimensional screen with multi-planar reconstructions (Conventional viewer, CV, GE Centricity PACS RA1000 Workstation, GE, United States). The protocol included four sets of items: calcification, dilatation, patency, and tortuosity as well as the number of lumbar and renal arteries. Interobserver agreement (IA, Cohen's Kappa, ) was calculated for every item set.

Results: All CTAs could successfully be displayed in the MRV (100%). The MRV demonstrated equal or better IA in the assessment of anterior and posterior calcification (: 0.68 and 0.61, : 0.33 and 0.45, respectively) as well as tortuosity (: 0.60, : 0.48) and dilatation (: 0.68, : 0.67). The CV demonstrated better IA in the assessment of patency (: 0.74, : 0.93). The CV also identified significantly more lumbar arteries (CV: 379, MRV: 239, < 0.01).

Conclusions: The MRV is a feasible imaging viewing technology in clinical routine. Future efforts should aim at improving hologram quality and enabling accurate registration of the hologram with the physical patient.