Abstract
Abstract Fluoroscopy and digital subtraction angiography provide guidance in endovascular aortic repair (EVAR) but introduce radiation exposure and require the administration of contrast agent. To overcome these disadvantages, previous studies proposed to display the pose of an electromagnetically (EM) tracked catheter tip within a three-dimensional virtual aorta on augmented reality (AR) glasses. For further guidance, we propose to create virtual angioscopy images based on the catheter tip pose within the aorta and to display them on HoloLens. The aorta was segmented from the computed tomography (CT) data using MeVisLab software. A landmarkbased registration allowed the calculation of the pose of the EM sensor in the CT coordinate system. The sensor pose was sent to MeVisLab running on a computer and a virtual angioscopy image was created at runtime based on the segmented aorta. When requested by HoloLens, the last encoded image was sent from MeVisLab to the AR glasses via Wi-Fi using a remote procedure call (gRPC), and then decoded and displayed on HoloLens. For evaluation purposes, the latency of transmitting and displaying the images was measured using two different lossy compression formats (namely JPEG and DXT1). A mean latency of 82 ms was measured for the JPEG format. On the other hand, using the DXT1 format, the mean latency was reduced by 87 %. This study proved the feasibility of creating pose-dependent virtual angioscopy images and displaying them on HoloLens. Additionally, the results showed that the DXT1 format outperformed the JPEG format regarding latency. The virtual angioscopy may add valuable additional information for guidance in radiation-sparing EVAR procedure approaches.
Highlights
Endovascular aortic repair (EVAR) of abdominal aortic aneurysms is a minimal-invasive technique in which a stent graft is implanted to avoid the rupture of the aorta
For supplementary guidance in this setup, we propose to display virtual angioscopy images based on the current pose of the tracked catheter tip on a virtual 2D canvas using HoloLens
A computed tomography (CT) scan of this phantom was acquired with the following device and parameters: Siemens SOMATOM Definition AS+, matrix size 512 x 512 x 1834, slice thickness 0.6 mm, The proposed system was capable of streaming the virtual angioscopy images corresponding to the catheter tip pose to HoloLens (Figure 2)
Summary
Endovascular aortic repair (EVAR) of abdominal aortic aneurysms is a minimal-invasive technique in which a stent graft is implanted to avoid the rupture of the aorta. Fluoroscopy and digital subtraction angiography (DSA) provide tool guidance during this procedure in which a catheter is used to place the stent graft. These imaging techniques introduce disadvantages such as radiation exposure and the administration of nephrotoxic contrast agent. An approach to overcome the current disadvantages of guiding EVAR procedures is based on displaying the pose of an electromagnetically (EM) tracked catheter tip in a three-dimensional (3D) preoperative computed tomography (CT) volume [1]. For supplementary guidance in this setup, we propose to display virtual angioscopy images based on the current pose of the tracked catheter tip on a virtual 2D canvas using HoloLens. This study assessed the feasibility and latency of transmitting and displaying virtual angioscopy images using two different lossy compression formats on the AR glasses
Sign-in/Register to view highlights & summary 
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call