MacOS 27 compatibility

[Haralampos Ladopoulos]

Hello everyone

So can we upgrade to MacOS 27 and continue running Horos 4.0.1 or do we have to wait for a newer version of Horos?

Thanks!

[Hiroaki Inomata]

Hi,

Horos v4.0.1 crashes the viewer on macOS 27.

It is up to you whether to wait for a fix.

The repository's "Issues" page lists various development versions.
https://github.com/horosproject/horos/issues
Trying those out is one option.

By the way, the pace of development for the Horos project itself has
slowed down recently.
You might want to consider switching to a different application.
If you check the Mac App Store, you will find plenty of apps available
for free or at low prices (under $10 USD).

iCat Solution, which previously supported Horos, has released the Falcon series.
https://apps.apple.com/us/app/falcon-mx-dicom-viewer/id1494173140
I also distribute the Phorlix series.
https://apps.apple.com/us/app/phorlix-lite-dicom-viewer/id6740269806

In terms of fundamental design, these newer apps are superior to Horos.

I believe there are alternatives available, even if a new version of
Horos isn't released.


Hiroaki Inomata, MD

2026年9月20日(日) 14:52 Haralampos Ladopoulos <ladop...@gmail.com>:

>
> Hello everyone
>
> So can we upgrade to MacOS 27 and continue running Horos 4.0.1 or do we have to wait for a newer version of Horos?
>
> Thanks!
>

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[Haralampos Ladopoulos]

Transition from Horos to Falcon MX is not very easy. I use two DICOM nodes for remote access, I have already setup same albums and I have a 1TB database. There is not an import settings option on Falcon so I just have to wait for a Horos update. 

Thanks!

[Hiroaki Inomata]

1TB of study data in Horos?
That’s a massive amount of data!
With that kind of volume, it might be a good time
to consider shifting over to a dedicated PACS to handle it all smoothly.



2026年9月20日(日) 18:46 Haralampos Ladopoulos <ladop...@gmail.com>:

> To view this discussion visit https://groups.google.com/d/msgid/horos-project/09016ea7-ab77-4cfe-8373-d4f761306d65n%40googlegroups.com.

[Haralampos Ladopoulos]

1TB on external SSD that works flawlessly on Horos Locations 

[Hiroaki Inomata]

>I have already set up the same albums and I have a 1 TB database. There is no import settings option in Falcon.

Albums are specific to Horos/OsiriX, so I wouldn’t expect a recently
developed viewer to support importing them.

I implemented the initial version of the ROI-color-rotation-UI in
response to a user request and submitted it to Horos as a pull
request, which was later merged:
https://github.com/horosproject/horos/issues/342
At the time, I found that the ROI state was stored in a Horos-specific
format rather than a standard DICOM object — a design choice I did not
particularly like.

Modern DICOM viewers should prioritize interoperable DICOM data over
proprietary application formats.
As shown in the attached screenshots, segmentation and ROI data
created by PHORLIX can be viewed in other viewers, including Weasis.

If Horos albums work for you, that’s fine.
I simply prefer portable DICOM over proprietary application data.


Hiroaki Inomata, MD

2026年9月20日(日) 22:34 Haralampos Ladopoulos <ladop...@gmail.com>:

> To view this discussion visit https://groups.google.com/d/msgid/horos-project/c526b1e2-6a24-4597-98cf-b029e2a92980n%40googlegroups.com.

[Haralampos Ladopoulos]

Το Falcon MX στο Apple Store κατεβαίνει και εγκαθίσταται χωρίς πληρωμή. Στην έκδοση αυτή μπορείς να διαμορφώσεις τις ρυθμίσεις του listener καθώς και ένα dicom node. Μπορείς να δοκιμάσεις την συνδεσιμότητα του node που έφτιαξες αλλά δεν μπορείς να κατεβάσεις εξετάσεις από το PACS. Στην δοκιμή αυτή το αποτέλεσμα είναι ping offline....

Όταν στην απλή αυτή δοκιμή το πρόγραμμα αποτυγχάνει πώς θα το εμπιστευτώ ώστε να το αγοράσω...

Και το ερώτημα παραμένει. Υπάρχει οδηγός μετάβασης από το Horos στο Falcon?

[Hiroaki Inomata]

For context, I have no affiliation with Falcon. I mentioned it only because
iCat Solution has described Falcon as the successor to Horos.

As far as I know, DICOM does not define a single, universal command
for transferring all studies from one PACS or DICOM database to another.
The actual migration workflow depends on the features implemented by
each application.

You may already know this, but the simplest way to transfer studies is
to use DICOM Send, which uses the C-STORE operation.

PHORLIX supports C-STORE as a Storage SCP.
In PHORLIX, click the PACS button in the database window, set the AE
title and listening port in the PACS panel,
and click Start. PHORLIX will then wait for incoming DICOM associations.
To send studies from Horos or HorliX, add PHORLIX as a DICOM network
node using PHORLIX’s IP address, AE title, and port.
Then select one or more studies and choose “Export to DICOM Network
Node” (DICOM Send).
Multiple studies can be sent in one operation.
In my experience, this workflow generally works, although individual studies
may occasionally fail to transfer and need to be retried.

By the way, i could implement a dedicated migration utility if needed,
but I have not needed one myself.
HorliX still runs in my Golden Gate environment, so I have no need to
migrate my own data.

Hiroaki Inomata, MD

2026年9月21日(月) 11:50 Haralampos Ladopoulos <ladop...@gmail.com>:

[Aðalsteinn Atli Guðmundsson]

I have found a  temporary solution for my Horos crashing on MacOS 27: Reducing screen resolution.

For me, Horos opens normally with the list of studies, but when I try to open a study to view the images, it immediately crashes.

If I disconnect my laptop from all external displays, then Horos works! My laptop's screen resolution is 1512x982.

If I have my laptop in clamshell mode (lid closed) and connected to a single external monitor, Horos crashes when that monitor is in it's default resolution (2560x1440), but if I reduce the resolution of that display Horos works fine!
Best resolution that Horos runs on for me is 1600x900.

So if you need to run Horos before a fix is applied, go to System Settings -> Displays and make sure all connected and built-in displays are set to a resolution of 1600x900 or smaller. For some displays, you'll have to click "Advanced..." and enable "Show resolutions as list" to be able to manually select a resolution.
I haven't tried, but I'm betting this will also work if you're running Horos on an iMac, Mac Studio or Mac Mini.

Note that after enabling "Show resolutions as list" you can press "Done" and also enable "Show all resolutions" below the list of resolutions to get a longer list of resolutions but some of those may have aspect ratios that don't fit your screen causing some sides of the display to become black and unused while that resolution is selected. Perhaps, on your display and with all resolutions enabled, you can select something greater than 1600x900 that works, but for me, that is the max.