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YOU CAN 3D PRINT YOUR OWN MRI SCANNER

OSI2 ONE — the first open-source MRI: a 3D-printed Halbach array with 396 magnets that genuinely images heads and limbs.

by OSI2 / Open Source Imaging initiative

FULL CAD BOM FIRMWARE DOCS

Medical-devicesScientific-instruments

difficulty
●●●●●
time
months
license
NOASSERTION (check docs — hardware licenses vary per part)
repo
repo ACTIVE63 stars

WHAT YOU’LL NEED

  • 3D printer + filament — printable parts — files are in the repo
  • Electronic parts — full list with part numbers in the repo BOM
  • Dev board / microcontroller — runs the project firmware

Partner

Show off your build — Record and edit your build video by editing the transcript, not the timeline.Try Descript
Videos
1

COMPAREE VERDICT

This is not a weekend build — it's an expedition. But it is real: working copies run in university labs in Utrecht, Leiden and Berlin, scanning heads and limbs. For 99% of people this is a page to read, not to build — and even then it's fascinating to know MRI is no longer a black box. If you're serious about building: start with the Halbach array chapter, that's the heart of the machine.

NOT IN THE REPO

  • —This is full open documentation, not a 'print and play' kit — you need 396 NdFeB magnets and serious metrology

Can I build this?

PrintHalbach magnet frame + formers — large FDM prints
Buy396 NdFeB magnets, RF coils, amplifiers, SDR electronics → full BOM in docs
Tools3D printer + electronics workshop + measurement gear
Skillselectronics ✓✓ · RF basics · methodical calibration
Timemonths
Costband $$$ — current prices in project BOM
SafetyVERY strong magnets — pacemaker/implant hazard, pinch injuries; keep tools and cards away

Very strong magnets — keep away from pacemakers, cards and fingers.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

Videos

OSI² ONE: An Open Source Low-Field MRI Scanner11:56

Gallery

The finished Halbach magnetLilisProtoLab / Utrecht
Halbach frame during the buildLilisProtoLab
Magnet ring close-upLilisProtoLab
Official OSI² ONE feature imageopensourceimaging.org

Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Read the project overview docs (understand the architecture first)
  2. 2.Halbach array chapter(the heart of the machine)
  3. 3.Join the Open Source Imaging community (builders + researchers forum)

Resources

Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.

KNOWN ISSUES

  • Magnet field calibration and temperature drift are the hard parts — budget time for shimming
  • It's low-field (~50 mT): images are genuinely useful but noisier than clinical 1.5 T machines
  • The linked GitHub repo is the educational 'OSII Mini' — the full-scale OSI² ONE lives on gitlab.com/osii.
  • Shimming the magnet field is the real challenge; each array ends up unique.

Is it safe?

The field is ~50 mT — about 30× weaker than a hospital MRI. Still: strong magnets, implant and pinch hazards apply.

Are the images actually usable?

Yes for research and education — labs in Utrecht, Leiden and Berlin image heads and limbs with it. It's not a clinical diagnostic device.

Can one person build it?

In principle yes, in practice it's a team/lab project. Join the community — nobody builds this alone.

Is this repo the actual OSI² ONE?

Not exactly — the GitHub repo we link is 'OSII Mini', an educational 120 mm version from Utrecht. The full clinical-scale OSI² ONE documentation lives at gitlab.com/osii. Both are worth exploring.

How homogeneous is the field?

Every Halbach array is unique after shimming — builders aim to get inhomogeneity from ~15,000 ppm down under 3,000 ppm. It's the hard, patient part.

Community builds

No community builds yet — be the first, we feature the best ones.

Discussion1

FROM THE COMPAREE TEAM

Every hand-built Halbach array ends up unique — builders shim field inhomogeneity from around 15,000 ppm down under 3,000. Would you sign up for that kind of patient, invisible calibration work?

CompareeTEAM1mo ago

Two findings from our source-tracing: the GitHub repo we link is actually the educational 120 mm 'OSII Mini' from Utrecht, while the full-scale OSI2 ONE documentation lives on GitLab — and the design has been replicated far beyond Europe, including a build in Paraguay. The consistent message from builders is that shimming the 396-magnet array is the real project. Anyone here from a physics lab tempted to try?

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You Can Build a Pocket DNA Lab That Runs From USB

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OSI2 / Open Source Imaging initiative

An open-science community of MRI researchers publishing the full design of a working low-field MRI so any lab can build and improve it.

GitHub Web

Star the project on GitHub

DISCLAIMER

  • Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
  • Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
  • Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
GitHub repo