Real-Time Ultrasoundsimulation for Medical Training

This thesis presents a real-time capable GPU-based ultrasound simulator suitable for medical education. Two different models are presented in the following. A 2D version has been implemented in order to simulate IVUS without modelling complex 3D geometry and a 3D version which is able to synthesize realistic looking ultrasound images in real-time. This includes ultrasound specific artifacts, which are essential for the interpretation of this data. The focus of this thesis is on the more general 3D version, that can simulate all common ultrasound modalities and is based on a convolution-enhanced ray-tracing approach which uses a deformable mesh model. This method advances the state of the art for real-time capable ultrasound simulators by following the path of the ultrasound pulse, which enables better simulation of ultrasound-specific artifacts. We evaluate our proposed method by comparison it to recent generative slicing-based strategies as well as real ultrasound images. Therefore, a gelatin ultrasound phantom containing syringes filled with different media is scanned with a real transducer. The obtained images are then compared to images which are simulated using a slicing-based technique and our proposed method. The particular benefit of our method is the accurate simulation of ultrasound-specific artifacts like range distortion, refraction and acoustic shadowing. Several benchmark scenarios are evaluated regarding simulation time, to show the performance and the bottleneck of our method. While being computationally more intensive than slicing techniques, our simulator is able to produce high-quality images in real-time, tracing over 5000 rays through mesh models with more than 2 000 000 triangles.