Fusion needs
a licence key.
The installer is free to download. Your subscription key is what unlocks processing. Subscribe once and the key appears here instantly.
Installers.
One honest warning.
These builds are not yet code-signed. Signing certificates cost money the project doesn’t have yet, so your OS will warn it can’t verify the publisher. Every build is produced by the public CI pipeline, from source you can read.
- macOSRight-click the app → Open → Open. If it still won’t open:
xattr -d com.apple.quarantine "/Applications/Penfield Fusion.app" - WindowsSmartScreen → More info → Run anyway.
- LinuxAppImage just runs;
.debinstalls with apt.
First launch seeds a demo brain (T1 MRI, 133 segmented structures) so the workspace opens with real anatomy to explore. Cold start takes about 30 seconds while the segmentation engine loads. The full user guide covers import, the workspace, QC, exports and troubleshooting, and ships inside the app.
Research software.
Fusion is research and exploration software, not a medical device and not for clinical diagnosis. Segmentation output is research-quality: QC warnings and manual review are part of the workflow, not optional extras.
Requirements: macOS 12+, Windows 10+, or a recent Linux desktop. ~8 GB free disk space (the segmentation model is bundled, ~2 GB of it). GPU acceleration when available: Apple Silicon, NVIDIA CUDA, or CPU fallback.