You might need to download DirectX 8.1 if:
It expanded support for 3D textures, which are essential for rendering complex effects like fog, clouds, medical imaging data, or animated noise patterns within a 3D space. directx 8.1 download
DirectX 8.1 is from 2001. Do not install it on modern Windows 10/11 unless you are running it inside a VM or with compatibility layers (e.g., using DirectX wrappers like dgVoodoo2 or DxWnd), as it can break newer DirectX versions. You might need to download DirectX 8
Download DirectX 8.1 from Microsoft's Official Website medical imaging data