UltraG-Ray: Physics-Based Gaussian Ray Casting for Novel Ultrasound View Synthesis

Felix Duelmer, Jakob Klaushofer, Magdalena Wysocki, Nassir Navab, Mohammad Farid Azampour

Keywords: Ultrasound, Novel View Synthesis, Volumetric Representation, Gaussian Splatting, 3D Ultrasound Reconstruction

TL;DR: We introduce a learnable 3D Gaussian ultrasound scene representation coupled with a physically grounded ray casting model that separates attenuation from reflection, enabling realistic, view-dependent novel ultrasound view synthesis.

Abstract: Novel view synthesis (NVS) in ultrasound has gained attention as a technique for generating anatomically plausible views beyond the acquired frames, offering new capabilities for training clinicians or data augmentation. However, current methods struggle with complex tissue and view-dependent acoustic effects. Physics-based NVS aims to address these limitations by including the ultrasound image formation process into the simulation. Recent approaches combine a learnable implicit scene representation with an ultrasound-specific rendering module, yet a substantial gap between simulation and reality remains. In this work, we introduce UltraG-Ray, a novel ultrasound scene representation based on a learnable 3D Gaussian field, coupled to an efficient physics-based module for B-mode synthesis. We explicitly encode ultrasound-specific parameters, such as attenuation and reflection, into a Gaussian-based spatial representation and realize image synthesis within a novel ray casting scheme. In contrast to previous methods, this approach naturally captures view-dependent attenuation effects, thereby enabling the generation of physically informed B-mode images with increased realism. We compare our method to state-of-the-art and observe consistent gains in image quality metrics (up to 15\% increase on MS-SSIM), demonstrating clear improvement in terms of realism of the synthesized ultrasound images.

Primary Subject Area: Image Synthesis

Secondary Subject Area: Image Acquisition and Reconstruction

Registration Requirement: Yes

Visa & Travel: No

Read CFP & Author Instructions: Yes

Originality Policy: Yes

Single-blind & Not Under Review Elsewhere: Yes

LLM Policy: Yes

Submission Number: 76