OP09.04: Improving 3D ultrasound interpretation of fetal anatomy using a virtual reality system

Abstract

To present images of fetal structures obtained with 3D ultrasound as hologram-like 3D visualizations that appear to hover in space in a small purpose-built room and can be manipulated by the viewer. Images obtained from a GE Voluson 730 Expert system are transferred to the BARCO I-Space virtual reality system. In the I-Space investigators are surrounded by computer-generated stereo images which are projected on three walls and the floor. Wearing glasses with polarizing lenses, viewers can examine ‘holographic’ renderings of their datasets. A wireless optical tracking system follow head and hand/joystick movements, to allow interaction and perspective correction. We use a 3D texture mapping technique to create the volume renderings of the datasets. Bi-ocular depth perception and correct perspective provides a realistic 3D illusion that allows better assessment of fetal structures. With the joystick the viewer can apply one or more clipping planes to the volume, making it possible to have an unobstructed view of any part of the fetal anatomy. The viewer can also control the rendering parameters interactively, to obtain a better quality image. One of the great advantages of this method is that several observers, one of them usually an instructor, can stand around the ‘hologram’ and watch simultaneously while it is being manipulated with the joystick-pointer. This is particularly useful for teaching operators who are new at 3D ultrasound. Another advantage is that the image can be reproduced in fine detail at a magnification of up to 50 times: a 16 mm embryo is thus being presented at a size of 80 cm which makes tiny fetal structures—such as toes, labia and ears, observable and measurable in a way that was not possible until now.