Gaussian Volumetric Representation for Efficient Shear–Warp Visualization

Shear–warp rendering using Gaussian representation

Full Head

Brain

Liver

Heart

Lung

Abstract

Medical image visualization requires volumetric rendering algorithms that preserve anatomical fidelity while maintaining high rendering speeds. To address the high computational cost of large volumetric datasets, we propose a Gaussian-based volumetric representation for efficient visualization of dense medical volumes without compromising structural and radiometric details.

The proposed representation is optimized using Monte Carlo volumetric estimation, which enables training on a highly sparse subset of voxels while maintaining consistency with the dense volumetric objective. In addition, we introduce a curriculum learning strategy that progressively incorporates structured slice-based sampling during training. Sparse voxel samples provide an early global coverage of the volume, while slice samples capture spatially correlated regions that aid geometric structure and texture continuity. This combination enables the Gaussian representation to learn anatomical details of various structures and corresponding textures from sparse supervision while significantly reducing the computational cost associated with dense voxel processing. The learned representation supports slice-based rendering methods such as shear–warp volume rendering, enabling efficient visualization of multimodal medical datasets including MRI and Cryosection volumes while preserving anatomical structures. Using sparse supervision, our method achieves up to 43.86 FPS rendering with a compression ratio of 11.31:1.

Sparse representations

Comparisons with learning based volumetric representation methods.

Cross
section
MLP sagittal Slice MLP sagittal Transformer sagittal UNet sagittal Ours sagittal GT sagittal
Cross
section
MLP coronal Slice MLP coronal Transformer coronal UNet coronal Ours coronal GT coronal
Rendered
view
MLP rendered Slice MLP rendered Transformer rendered UNet rendered Ours rendered GT rendered
Voxel MLP Slice MLP Trans former UNet Ours GT
Reconstruction Quality Rendering Quality
Method PSNR ↑ MSE ↓ SSIM ↑ MS-SSIM ↑ PSNR ↑ MSE ↓ SSIM ↑ MS-SSIM ↑
Voxel MLP 23.63 0.000434 0.772 0.871 46.610 0.000176 0.968 0.980
Slice MLP 30.02 0.000995 0.920 0.969 36.32 0.000248 0.973 0.983
Transformers 9.60 0.052000 0.631 0.404 29.73 0.014900 0.873 0.481
UNet 26.70 0.002130 0.798 0.943 42.10 0.00052 0.982 0.985
Ours 34.81 0.000398 0.956 0.993 54.87 0.000021 0.995 0.993

Ablation study

Visual comparisons of the ablation study on cross sections and rendered views from shear-warp renderer.

Cross
section
A₁ A₂ A₃ A₄ A₅ Ours GT
Rendered
view
A₁ A₂ A₃ A₄ A₅ Ours GT
Rendered
view
A₁ A₂ A₃ A₄ A₅ Ours GT
A₁ A₂ A₃ A₄ A₅ Ours GT
Reconstruction Quality Rendering Quality
Method PSNR ↑ MSE ↓ SSIM ↑ MS-SSIM ↑ PSNR ↑ MSE ↓ SSIM ↑ MS-SSIM ↑
A₁ 33.46 0.000451 0.956 0.990 50.7 0.0002400 0.962 0.964
A₂ 12.16 0.0054300 0.060 0.214 27.10 0.025800 0.826 0.789
A₃ 22.64 0.005439 0.727 0.850 40.59 0.000782 0.932 0.937
A₄ 14.350 0.0366 0.646 0.512 33.18 0.005020 0.878 0.887
A₅ 32.40 0.000576 0.943 0.988 52.34 0.000161 0.968 0.991
Ours 34.81 0.000398 0.956 0.993 54.870 0.000021 0.995 0.993

Rendered views various datasets

Visual results of rendered views of different organs from Cryosection, BraTS MRI, and Mouse neonatal MRI datasets.

GT Brain GT Liver GT Heart GT Lung GT BraTS GT Mouse Neonatal GT
Pred. Brain Pred Liver Pred Heart Pred Lung Pred BraTS Pred Mouse Neonatal Pred
Brain
Cryo
Liver
Cryo
Heart
Cryo
Lungs
Cryo
BraTS
MRI
Mouse
MRI
Dataset PSNR SSIM MS-SSIM FPS Compression ratio
Brain (Cryo) 32.10 0.943 0.991 45.5 9.34:1
Liver (Cryo) 43.16 0.981 0.996 50.18 9.45:1
Heart (Cryo) 32.19 0.958 0.990 48.57 10.09:1
Lungs (Cryo) 34.93 0.952 0.989 39.77 4.73:1
BraTS (MRI) 40.88 0.988 0.998 44.82 11.31:1
Mouse Neonatal (MRI) 33.48 0.956 0.987 46.56 9.94:1