P801 A virtual reality tool for measurement of 3D echocardiographic images

Abstract

Abstract Funding Acknowledgements Work supported by the NIHR i4i funded 3D Heart project [II-LA-0716-20001] Background/Introduction Cardiac measurements are clinically important and are invariably required in any clinical imaging software. The advent of Virtual Reality (VR) imaging systems is introducing intuitive and natural ways of visualising and interrogating echo images in a 3D environment. The 3D nature of the VR experience requires purpose-designed measurement tools, which may benefit from better depth perception and easier localisation of 3D landmarks. Purpose Comparison of the accuracy of our VR 3D linear measurement system to commercial clinical imaging software, using both multi-plane reformatting (MPR) and volume rendered views. Method Each virtual reality measurement was made by selecting two points in 3D, directly in the volume rendering. The participants could edit the measurements until satisfied with their accuracy. 5 expert clinicians carried out 26 measurements each - 6 measurements on a calibration phantom, and 5 anatomically meaningful measurements (for example: aortic valve, left atrium, left ventricle) on 4 datasets. The same measurements were made by all participants using our VR system (volume rendering), Philips" QLAB (MPR) and Tomtec (volume rendering). The frame number and view (for example: long axis) were consistent for each measurement across the 3 packages used. Results Preliminary results are shown in the figure below. MPR measurements made on Philips’ QLAB are used as a reference, as this is the most commonly used software for this purpose at our institution. We compare measurements made in Tomtec and VR, both using volume rendering, using Bland-Altman plots. Each measurement data point is the mean of all participants measurements for each dataset/measurement combination. The mean of the measurement differences for the VR system is closer to zero, compared to Tomtec. However, the variation of these differences is larger for the VR system than for Tomtec. Conclusion Our preliminary results suggest that the accuracy of line measurements made using volume rendering within a VR system is comparable to measurements made using approved software packages for volume rendering displayed on a 2D screen. This shows promise for more complex interrogation methods. Abstract P801 Figure. Comparison of Tomtec and VR with QLAB