Magnetic resonance cholangiopancreatography enhanced by virtual reality as a novel tool to improve the understanding of biliary anatomy and the teaching of surgical trainees

Abstract

Objective: The novel picture archiving and communication system (PACS), compatible with virtual reality (VR) software, displays cross-sectional images in VR. VR magnetic resonance cholangiopancreatography (MRCP) was tested to improve the anatomical understanding and intraoperative performance of minimally invasive cholecystectomy (CHE) in surgical trainees.

Design: We used an immersive VR environment to display volumetric MRCP data (Specto VR^TM). First, we evaluated the tolerability and comprehensibility of anatomy with a validated simulator sickness questionnaire (SSQ) and examined anatomical landmarks. Second, we compared conventional MRCP and VR MRCP by matching three-dimensional (3D) printed models and identifying and measuring common bile duct stones (CBDS) using VR MRCP. Third, surgical trainees prepared for CHE with either conventional MRCP or VR MRCP, and we measured perioperative parameters and surgical performance (validated GOALS score).

Setting: The study was conducted out at Clarunis, University Center for Gastrointestinal and Liver Disease, Basel, Switzerland.

Participants: For the first and second study step, doctors from all specialties and years of experience could participate. In the third study step, exclusively surgical trainees were included. Of 74 participating clinicians, 34, 27, and 13 contributed data to the first, second, and third study phases, respectively.

Results: All participants determined the relevant biliary structures with VR MRCP. The median SSQ score was 0.75 (IQR: 0, 3.5), indicating good tolerability. Participants selected the corresponding 3D printed model faster and more reliably when previously studying VR MRCP compared to conventional MRCP: We obtained a median of 90 s (IQR: 55, 150) and 72.7% correct answers with VR MRCP versus 150 s (IQR: 100, 208) and 49.6% correct answers with conventional MRCP, respectively (p < 0.001). CBDS was correctly identified in 90.5% of VR MRCP cases. The median GOALS score was higher after preparation with VR MRCP than with conventional MRCP for CHE: 16 (IQR: 13, 22) and 11 (IQR: 11, 18), respectively (p = 0.27).

Conclusions: VR MRCP allows for a faster, more accurate understanding of displayed anatomy than conventional MRCP and potentially leads to improved surgical performance in CHE in surgical trainees.

Keywords: 3D printing; bile duct anatomy; immersive virtual reality; magnetic resonance cholangiopancreaticography (MRCP); minimally invasive cholec; surgical skills training.

Figure 1

Phasewise study set up. First phase: Establishing the basics of VR MRCP experiences regarding the tolerability and overall safety of the VR experience and understanding of the displayed anatomy. Second phase: Direct comparison of conventional and VR MRCP's ability to demonstrate pathological findings. Third phase: Assessing the potential clinical usefulness of VR MRCP.

Figure 2

(A) A 3D MRCP reconstructed scan viewed by a participant in a virtual room compared to (B) a conventional digital imaging and communications in medicine (DICOM)-viewed MRCP scan. Participants were allowed to take as long as necessary to view the scans in the respective modality. Fifteen MRCP scans were 3D printed, and the candidates were asked to choose the correct model (C,D).

Figure 3

The 3D MRCP model in the VR environment as seen by the viewer. (A) The model can be rotated, zoomed, moved freely, and displayed as a VR medical examination room. (B) By using the freely adjustable cutting plane, the original scan can be seen through the model.

Figure 4

Box plots with 95% confidence intervals, with error bars showing (A) the number of correct answers as a percentage—left, conventional MRCP, and right, VR MRCP, and (B) the time needed to achieve sufficient understanding of the depicted anatomy—left, conventional MRCP, and right, VR MRCP.