How does Orthanc compare to dcm4chee?

Hello all,

I’m currently evaluating different PACS systems to see which one is a better fit for my organization. So far, the top contenders are Orthanc and dcm4chee. The issue I’m running into is that I can’t find any comparisons online. Do any of you have experience with dcm4chee? Can you tell me some of the advantages/disadvantages of using Orthanc over dcm4chee?

Thank you for considering this.


As far as I’m concerned, I am strongly biased. Consequently, I cannot provide any hint on this topic.


I have installed both on a Centos Machine from source, rebuilding all of it 1/2 day for Orthanc 1 week for dcm4chee
Orthanc is really lightweight compared to dcm4chee that is a litle like a monster … with tons of useless features to be configured of course.
The community around orthanc especially Sebastien is very reactive, the doc is always uptodate
dcm4chee has a better user interface with much more features but I do not care as I have my own user interface
HL7 on dcm4chee is ok but what a work !
a the end i removed dcm4chee …
have fun !

Depends on what you are looking for. If you want a rock solid PACS that you can build your own applications on top of then Orthanc cant be beat.

Response will be biased as you are in Orthanc forum and so you will have more Orthanc fans than DCM4CHEE.

I installed and used DCM4CHEE before discovering Orthanc.

The advantages of orthanc, to me, are :

  • Lightweight
  • Full API

And so it provides a very interesting DICOM engine to put in many application.
It is also the perfect candidate for research project and small / middle institution.

On the interface, there are other project in orthanc community that tries to fill the gap (i lead two of them, so I’m going to save you from advertising) there are also several commercial distribution of orthanc that provides such handy distributions of Orthanc.

On the DMC4CHEE advantage i would say his history. It is much older than Orthanc and so implement a lot of functionalities which comes with the price of complexity.
I think if i have to deploy a pacs production in a huge academic hopsital with hundreds of TB of dicom I would use DCM4CHEE just because of its history and it’s multiple functionality, especially the HL7 integration.

So in my opinion for 95% of use cases, Orthanc is the good candidate.

Best regards,


I would also want to say that one of the value of Orthanc is also Sebastien’s devotion and largness of spirit as well as Osimis team.

I think not everything is technichal in software project.

I’m not saying DMC4CHEE is not devoted ( I don’t know them), but just wantedto add that Orthanc has a tremendous evolution these last years, they built an incredible ecosystem, community, with a good leadership and a strong comitement to free/libre software.

more than the technical side, the human side is probably the most important factor.

I used DCM4CHEE for years, and it is solid and capable
I used it in a linux environment and it is not straightforward to install and get working. Once it is it is solid
Changing settings is documented but it is easy to “break” your install. I could never get the simple task of changing the AET name

to propogate through all the modules, even with online tutorials. So I had to operate with the default AET.

Orthanc on the other hand has been drop dead simple to install… I have it running on a couple of linux VM’s and even use it as

a web portal on a raspberry pi for referring Vets to view xrays of their patients at our Emergency center. I have a Lua script that

forwards studies so that they cant access the main pacs, but a rotation of the latest studies are available.

I even helped another Vet being held hostage by his xray vendor when his service contract ran out, and access to his films was about to become a very expensive monthly hybrid
on and offsite storage. Set up an orthanc instance, and thumbed our nose at the hostage takers

Very simple and straight forward to install and maintain. If you have a small install and use the base database… backing up your films is as simple as copying the files to another location.
re installing them… just copy them back to the working directory.

One caveat… if you mess up your json configuration file by even one comma, Orthanc won’t start, and you won’t see a warning
on your screen… (it might be logged though) So start with a plain vanilla example to get running and verify. Back up your config
with every change, especially if you make several changes. Very easy to walk back to what worked.

The lua scripting lets you do some neat stuff with minimal code.

So bottom line. DCM4CHEE served me well… but there’s no looking back for me. My life is much simpler with ORTHANC

For me I use both Dcm4Chee and Orthanc. My PACS infrastructure is built up on them. For simplicity, just considering they are dicom database like what you are using MySql, PosgresSQL or MongoDb… . Each of them has different advantage, example
1/ The most feature I like Orthanc is plugin. I can add whatever I want by using C++ plugin in Orthanc.
2/ The most feature I like Dcm4Chee is that it’s more IHE compliant. One of feature I use from Dcm4chee is Qido RS which allows me to upload multiple file types (jpeq, png, mp4, pdf, dicom) whilst Orthanc only supports few of them (I am not flowing them much closely but as far as I know, it only support pdf, dicom)
3/ Orthanc supports Worklist partially, but Dcm4chee supports Worklist fully.
4/ For the performance I observe that they run equally (at least for the wado-rs feature). Although Orthanc runs much lower RAM than Dcm4Chee (It can be easily notes by comparing C++ vs Java :slight_smile: ).

So in conclusion, depending on the situation and how large your PACS is, choosing Dcm4Chee or Orthanc is your own consideration.

P/S If anyone has any observation of the maximum studies/ storage usage, it would be very helpful. From the Orthanc book, it can contains 15Tb of dicom. But I have not had a number from Dcm4Chee. This feature can be a key when choosing Orthanc or Dcm4Chee.

Thank you all for the input! I would agree, Sebastien and the Orthanc community are a big selling point! For example, I posted a similar question to the dcm4che google group, and it took them much longer to give me a response.

For me the only real downside to Orthanc is that it’s written in C++. It’s a pretty uncommon skill in the world I work in (backend web & cloud). dcm4chee is written in Java, which makes crawling through the source code much easier.

I think for now, I’m going to go with Orthanc. dcm4chee seems much more heavyweight, and would probably be overkill for my purposes.

Thank you all for your help and input!


Hello everyone,

I am new to the world of RIS/PACS, I can see that Orthanc is a lightway, modern, web/cloud friendly server that eliminates a lot of set up overheard. What i can’t understand is what does “Complementing the main PACS” mean and why can’t it be a “main PACS”. My target is a medium sized clinic in a developing country, I don’t have any an idea about how much TB of dicom is generated daily in any kind of facility and I want to have a starting point to dig more into designing a full software architecture for the a medium sized clinic.

Mohamed Mounir.


I promised not to interfere in this thread, but here is my insight on Mohamed’s very specific question. This is a short, hopefully intuitive answer, that doesn’t intend to be universal (no flaming please!).

All depends on your definition of a PACS. In Europe, “PACS” often refers to the combination “VNA (i.e. DICOM server/store) + CE-certified viewer of medical images (focused on the clinical radiology workflow) + RIS (Radiology Information System)”. A typical PACS is also interfaced using HL7 messages to the other servers of the hospital, notably the HIS (Hospital Information System), the EHR (Electronic Health Record), and the Web publication portal (to share medical images with general practitioners and patients).

As far as the Orthanc project is concerned:

You can find hints about the scalability of the Orthanc server in the following FAQ, keeping in mind that we currently plan a large refactoring of the database schema to yet improve its performance:

Also, regarding the viewer for radiologists, if you don’t need FDA/CE certification, the Stone Web viewer can possibly be a solution, taking into account the fact that we plan to introduce support for 2D measurements, yet for 3D volume rendering (MPR) in next releases:

In your case of a developing country, if you don’t need a RIS, you could consider using the Orthanc server as a “PACS” (more precisely, a VNA), combine it with one free and open-source viewer for radiology workflow (cf., publish images using the Stone Web viewer, and deploy a free and open-source EHR such as GNU Health (cf.

I hope this clarifies my personal vision about the Orthanc project for clinical setups.

Kind Regards,


The main advantage of DCM4CHEE is that it’s an enterprise PACS. It has all the DICOM SOP Classes you can think of. It accepts any kind of medical image you can throw at it. The biggest challenge with DCM4CHEE is initial setup, that is if you’re installing it from scratch (on a linux or windows computer). In my case, I installed DCM4CHEE on a Synology NAS 5 years ago - DCM4CHEE comes as a prepackaged docker image on a number of Synology NAS boxes. It has been very reliable (1300+ bed capacity hospital). As for Orthanc, it is very easy to deploy, very easy to configure. I could have deployed Orthanc on Synology NAS but it’s package was still in Beta Version then. I usually deploy Orthanc in small clinics and it’s usually paired with OHIF Viewer. I install Lesion Tracker package (comes pre-integrated with Orthanc/OHIF) then update Orthanc part (I had trouble sending images from modalities to old versions of Orthanc). My advice: If you’re going for DCM4CHEE, get a pre-built image (there are so many Ubuntu Boxes out there with DCM4CHEE 3 pre-installed). If you’re going for Orthanc, don’t install it on Windows!! I’ve had several challenges with Orthanc on windows (Orthanc service keeps stopping for no reason). The best way to enjoy Orthanc is on Linux. It works flawlessly on OpenSuse. Final advice: If your organization is small, go for Orthanc. If you have multiple modalities with all kinds of image sources (endoscopy, dematology, ecg, etc), go for DCM4CHEE.



And i run successfuly Orthanc on windows 7TB studies already, 37GB postgres database. No issue at all.

a am also archiving studies every day on it so its quite busy all the time. No single failure.

Windows server 2019 essentials as VM on esxi.




I don’t want to interfere in the “DCM4CHEE vs. Orthanc” debate, but I hereby answer your sentence: “If you’re going for Orthanc, don’t install it on Windows!! I’ve had several challenges with Orthanc on windows (Orthanc service keeps stopping for no reason).”

There was indeed an issue regarding auto-restart of the Windows service in release 21.1.7 of the Windows installers by Osimis, and the 21.2.0 release improved the handling of errors in the Orthanc server. But we are not aware of any other problem regarding the Windows installers 21.2.0 by Osimis.

If you have an issue regarding Orthanc on Windows, please provide a minimal working example (e.g. a sequence of screenshots showing how to reproduce the stopping of the Orthanc service), so as someone can work on a fix:

Also, note that Orthanc should also accept by default any kind of DICOM image from any kind of DICOM modality. If this is not the case, please provide a sample DICOM file that isn’t ingested correctly by Orthanc.


I have to admit, my Orthanc instances on Windows were not on clean windows installations. The 1st one was on a Windows 10 Pro machine which had all sorts of application on it, including ORS VISUAL miniPACS. The other instance was on Windows Server 2016 with multiple docker containers. I suspected software or port conflicts but I didn’t pursue it further because it was just for testing purposes. I’m sure it should be better with a dedicated Windows machine.


Hi everybody,

Thank you all for your super fast and especially useful replies, and excuse me if my questions were not in the right thread, this one has been so informative for me that i forgot that its main subject was “How does Orthanc compare to dcm4chee?”. As soon as reached the bottom, i jumped right away to seek more information from this wonderful community.

At this point, I believe that Orthanc and its plugins will do the job. One last point that bugs me would be whether implementing the HL7 interface is a must, or can be bypassed somehow.

Mohamed Mounir.