MedScan vs OHIF Viewer: Native Offline App vs Zero-Footprint Web
Updated July 12, 2026 · 7 min read
OHIF is one of the best things to happen to open-source medical imaging. A serious, extensible, MIT-licensed viewer that runs in any browser, backed by an active community and adopted by hospitals and research platforms worldwide — that is a remarkable public good, and for institutional deployments it is often the right answer.
But "runs in any browser" describes the client, not the system. OHIF is a zero-footprint front end for a DICOMweb backend: somewhere, a server must store the studies, handle auth, and stream pixels. That architecture is a strength inside an institution and a dead end when you are holding a patient CD, standing in an operatory with no reliable Wi-Fi, or simply do not have anyone to run a server. MedScan is the architectural opposite — the entire pipeline, from JPEG 2000 decode to Metal volume rendering, lives on the iPad itself.
Side-by-Side
| MedScan | OHIF Viewer | |
|---|---|---|
| Architecture | Native iOS app; on-device decode and Metal GPU rendering | Web app (React); zero-footprint client for a DICOMweb backend |
| Price | Free tier; Pro from $4.99/week | Free, open source (MIT) — but you host the backend |
| Server required | None — opens local files, CDs, ZIPs directly | Yes — needs a PACS/DICOMweb server to stream from |
| Offline use | 100% offline, no account | No — requires network access to its backend |
| Dental tools | Arch/panoramic CPR + cross-sections, tooth numbering, Misch HU probe, CBCT presets | None built-in; extensible via custom modes |
| PACS | DICOMweb client (QIDO/WADO), Basic + OAuth2 PKCE | DICOMweb-native by design; institution-grade auth via backend |
| Formats | JPEG2000/Lossless/JPEG-LS/RLE; SEG, RTSTRUCT, RTDOSE, GSPS, SR, PDF, WSI | Broad, incl. SEG/RTSTRUCT/SR; depends on server transcoding for some codecs |
| MPR / 3D | Ax/sag/cor/oblique, slab MIP/MinIP/Avg, GPU volume rendering, PET/CT fusion | MPR, 3D and fusion via Cornerstone3D — capable, browser-bound performance |
The "server required" row is the whole comparison in miniature. Every OHIF capability assumes a maintained backend; every MedScan capability assumes only the device in your hand. Interestingly, the two meet in the middle at the protocol level — both speak DICOMweb (QIDO-RS/WADO-RS), so the same Orthanc or dcm4chee archive can serve both clients. What MedScan renders from such an archive, including SEG, RTSTRUCT, GSPS, and whole-slide imaging, is listed in the format reference.
Choose OHIF If…
- You are deploying a viewer for an institution: zero-footprint means nothing to install on hundreds of machines, and access control lives centrally on the backend.
- You need deep customization — OHIF's mode/extension system lets teams build tailored reading workflows, research overlays, and AI-result display on top of it.
- Open-source licensing is a hard requirement for procurement, research reproducibility, or vendor-neutrality reasons.
- Your users are on mixed platforms (Windows, Linux, ChromeOS) where one web client beats four native apps.
Choose MedScan If…
- You need to open local studies with no server at all — patient CDs, ZIP exports, DICOMDIR folders, AirDropped CBCT volumes.
- Offline is non-negotiable: rural clinics, mobile units, travel, or simply not wanting patient data to transit any server.
- You want native iPad performance — direct Metal GPU volume rendering and slab projections without browser memory ceilings.
- You are in dentistry and need panoramic reformats, tooth numbering, and Misch density readouts out of the box rather than as a custom development project.
Running Both
Because both clients are DICOMweb-native, "versus" is often the wrong preposition. A clean pattern for a clinic or research group: one Orthanc (or dcm4chee) archive; OHIF served to desktops for in-network browser reading; MedScan on iPads for chairside, bedside, and offline work, authenticated against the same server with OAuth2 PKCE. Studies cached on the iPad remain readable when the network is not, and annotated views can be pushed back as DICOM Secondary Capture. The on-device pipeline that makes this possible is described on the technology page.
FAQ
Does OHIF Viewer work on an iPad?
Yes, in Safari — OHIF is a web application, so it runs anywhere with a modern browser and a network path to its backend. Touch interaction and performance on large volumes are respectable but constrained by the browser; a native app has direct GPU access and works with local files without any server.
Can OHIF work offline?
Not in any practical sense. OHIF is designed as a zero-footprint client for a DICOMweb backend — it streams studies from a server. No server reachable, no studies. MedScan is the inverse: everything is decoded and rendered on-device, so airplane mode changes nothing.
OHIF is free — why would I pay for MedScan?
OHIF the software is free; running it is not effort-free. You (or your institution) must deploy and maintain a PACS backend, TLS, auth, and the viewer itself. If that infrastructure already exists, OHIF is excellent. If you just need to open a patient CD or a CBCT export on an iPad today, a native app with a free tier is the shorter path.
Can MedScan connect to the same backend as OHIF?
Usually yes. OHIF talks to DICOMweb servers (Orthanc, dcm4chee and others), and MedScan speaks the same QIDO-RS/WADO-RS protocols with Basic auth or OAuth2 PKCE. It is common for the same archive to serve OHIF in browsers and MedScan on iPads simultaneously.
Which has better dental tools?
MedScan. OHIF is a general-purpose radiology platform — extensible, but with no out-of-the-box dental workflow. MedScan ships arch-curve panoramic reformats with cross-sections, tooth numbering, CBCT window presets, and a Misch HU density probe for implant-site assessment.
Is either a certified medical device?
The open-source OHIF Viewer is provided as-is and is not itself a cleared device (commercial derivatives of it exist that are). MedScan is likewise not a medical device — it is a viewer and measurement tool. Use appropriately cleared software for regulated primary diagnosis.
Also compare: MedScan vs OsiriX · MedScan vs Horos · MedScan vs RadiAnt · Best DICOM viewer for iPad