Medical Imaging. Straight from your browser!

03/06/2016 | Thibault Piront | comments

Medical imaging and web interfaces used to be enemies. Heavy files that need lots of processing power… till recently, web browsers were simply not made to handle client side rendering.

The advent of HTML5 and more powerful Javascript engines has opened up a whole world of possibilities, including displaying medical images efficiently.

Orthanc, with its REST API, fits well in the new paradigm; any user can now access a PACS from the internet with simple HTTP requests. The Orthanc open source project has its own viewer. At Osimis we decided the world is ready for a more advanced open source viewer … and it’s also free.

Who needs it and why?

  • Large organizations can deploy it to instantly bring imaging access to anyone through their intranet.
  • Self-employed workers can get it to work with any medical modalities at their hands.
  • Software providers can develop their own services and softwares, using it as a library.

About Orthanc and Osimis

The viewer is integrated to Orthanc as a plugin. Orthanc is an internationally recognised open source DICOM framework. It can be used as a PACS or VNA and holds an extensive set of DICOM tools for managing automation.

The Osimis viewer comes as a plugin to Orthanc. In other words, the viewer can be connected to most modalities, but also leveraged through Orthanc's strong architectural extensibility.

Furthermore, the DICOM image storage can be integrated to any database backend and clinicians can organise their workflows around it in a way that suits just them.

Feature overview

On top of the usual standard DICOM viewing features like contrast, zooming, panning and measurements, less common formats like multi frame DICOM are also supported.

Here’s the exhaustive list of features that are available from a simple to use menu bar.

Zooming and Panning Zooming and Panning

Windowing management Windowing management

Color Inversion Color Inversion

Length measurement Length measurement

Angle measurement Angle measurement

Point/Circle/Rectangle of Interest informations Point/Circle/Rectangle of Interest informations Point/Circle/Rectangle of Interest informations

Image rotation Image rotation

Multiframe Multiframe


Heavy image is a common issue in usual image viewers. It is often frustrating for the end user to wait until these huge files have been fully loaded. To avoid this issue, the raw images are preprocessed into multiple, tinier, downsampled jpeg files compressed by the server plugin. Thanks to latest technologies, the web client download those multiples preprocessed images in a smart way to maximize efficiency while bringing the raw precision once it is available. As a result, everything looks fluid.


The viewer client have an extensible javascript architecture built on top of Angular 1.5. It can be used as a library to develop new viewers. Among things that are extensible or can be developed upon, here are some examples : additional 2D tools, the toolbar design, specific viewport overlays, custom "timelines", … you name it.

It can also be (and has already been!) embedded into platform native applications.


The viewer doesn't support MPR (multi-planar reconstruction), MIP (maximum intensity projection) or segmentation technologies as all of these functionalities are subject to CE Marking. More about that later ;)


As a matter of fact, a prototype of a segmentation algorithm using the webviewer has been codeveloped by Osimis and the IRCAD institute at the Hacking Health Strasbourg 2016 - (french presentation)

Mobile platforms are not yet supported, but tablet support will be available soon.


Like what you see? Also want to take advantage of all this free wealth? Here’s how you can do that. There are 3 ways to install the plugin with Orthanc :

  • Pre-built executable can be downloaded here (available for Windows and OS X).
  • Docker container procedure for linux is available here.
  • Source code and build instructions are available here.


Any questions / feedback –> send them here to Thibault

Osimis team thibault

Thibault Piront

Since he’s 7, Thibault has been learning the code. Ever since, he’s been passionate about all things digital, with a strong focus on the architecture side of software engineering. At Osimis, Thibault is mainly in charge of creating viewer features (that’s why we call him the Knight Rider) as well as optimizing what is optimizable.