DICOM viewer software is the program that opens a DICOM study so you can window, scroll, measure, and (sometimes) reconstruct. This page is a tools list. It is not a PACS explainer, not a Slicer click-path, and not a ranked “7 best.”
If you meant the archive / workbench → PACS and DICOM. If you meant hooking a PACS to the rest of the hospital → PACS integration. If you meant the long-term library → what is a VNA. If you meant open a file and paint a mask → Slicer + ITK-SNAP. If you meant a browser OHIF walkthrough → OHIF viewer overview. If you meant the hospital stack → medical imaging software.
PYCAD builds custom web DICOM viewers and imaging models. It is not a row on this list and not a ranked SKU. A live demo of one custom viewer sits at /dicom-viewer/ (a leftover page; different job).
What to pick on (not a trophy)
| Criterion | Why it matters |
|---|---|
| Primary diagnosis | Most free / research viewers are not cleared for the signed report in the US. OsiriX MD is. Horos, RadiAnt, MicroDicom, Slicer, Weasis, and Orthanc’s built-in viewer are not. That is a legal line, not a feature score. |
| OS | OsiriX / Horos are macOS. RadiAnt and MicroDicom are Windows. Slicer / Weasis / Orthanc are cross-platform. |
| 3D | MPR is table stakes. Volume rendering and a research segmentation toolkit are not. Do not buy Slicer to window a chest CT. |
| Network | A viewer that cannot C-STORE / Q/R against your PACS is a USB stick. Orthanc is the small server; the others consume one. |
| Web vs thick client | A browser viewer (Weasis web, Orthanc’s HTML, OHIF) is how you stop installing a workstation on every laptop. Thick clients still win on local 3D. |
Viewers teams actually use
No rank. No stars. Cleared-for-diagnosis is called out; the rest are secondary review, teaching, research, or a small archive.
| Tool | What it is | Useful bit | Catch |
|---|---|---|---|
| OsiriX MD | macOS PACS workstation + viewer | MPR / MIP / VR, fusion, a local archive. FDA-cleared for diagnosis | Mac only. Paid. Lite is not the diagnostic SKU. osirix-viewer.com |
| Horos | Open-source OsiriX fork, macOS | Same 3D toolkit, local database, plugins | Mac only. Not cleared for primary diagnosis. Community support. horosproject.org |
| RadiAnt | Fast Windows viewer | MPR (oblique), ROI / Cobb, C-STORE / Q/R, CD import | Windows. 3D is thinner than OsiriX. Not cleared for primary diagnosis in the US. radiantviewer.com |
| MicroDicom | Free Windows viewer | Window / zoom / pan, distance / angle / area, header dump, basic MPR | No PACS client. No serious 3D. Windows. microdicom.com |
| 3D Slicer | Open-source research platform | Segmentation, registration, Python, extensions. Cross-platform | Not a clinical workstation. Not cleared. The click-path is 3147. slicer.org |
| Weasis | Java viewer, desktop or web | Cross-platform, PACS / HIS hooks, layouts, basic 3D | Needs a JRE. Large series can feel slower than a native viewer. Weasis |
| Orthanc | Lightweight DICOM server + a simple web viewer | Storage / Q/R, REST API, anonymize, plugins. The viewer is a bonus | The built-in viewer is not a diagnostic workstation. You usually point a real viewer at it. orthanc-server.com |
OHIF is the other common web viewer. It has its own leftover page. A Windows-only twelve and a “free online” twelve also exist on this site; they are not this URL.
A sane way to choose
- Name the signed report. If a radiologist has to sign on this viewer in the US, you are buying a cleared workstation (OsiriX MD, or the vendor viewer that shipped with the PACS). Everything else is secondary review, teaching, or research.
- Name the OS and the network. A Mac lab is Horos or OsiriX. A Windows reading room that already has a PACS is RadiAnt or the vendor client. A mixed shop that needs a browser is Weasis / OHIF / a custom web viewer.
- Name the job after “open.” Window a chest → any of these. Paint a mask → Slicer / ITK-SNAP, not MicroDicom. Stand up a small archive → Orthanc, then pick a viewer.
- Do not buy a platform to open fifty studies. MicroDicom or Horos is enough. Buy a workstation when diagnosis or a PACS contract says so.
What this page is not
- Not a PACS, a VNA, or PACS training. Those are 7929, 7839, 7821.
- Not the Slicer walkthrough. That is 3147.
- Not a PYCAD viewer SKU. Custom web viewers are what we build; they are not item 8 on a trophy list.
- Not Outrank screenshots or a comparison matrix with invented stars. Dropped.
If the work is a viewer that has to live inside a clinic app, that is the imaging piece. Case studies.