Using Rest API When StoreDicom is set to false

I have thousands of DICOM studies stored locally. I would like to use Orthanc to index these studies without duplicating storage. I set the “StoreDicom” flag to false in the config file. However, if I try to use the REST API to modify metdata fields of an instance (see this example in orthanc book) I get a server-side error that says

“W0130 15:22:27.757200 ServerContext.cpp:587] Unable to read attachment dicom of instance d02kd923-as9dkf83-93kd93kd-3kd83kd8-38fjd83”

This error makes sense given the instructions that say “Orthanc allows to modify a set of specified tags in a single DICOM instance and to download the resulting anonymized DICOM file”. However, is there a way to modify a set of tags without requiring there to be underlying image data

I appreciate any advice!


Modifying a DICOM instance by Orthanc requires this DICOM instance to be stored within Orthanc, which is not the case if “StoreDicom” is set to “true”.

Setting “StoreDicom” to “false” does not mean that Orthanc separates the DICOM tags from the pixel data. It means that Orthanc only indexes a small subset of so-called “main DICOM tags” in its SQL database, then drops the source DICOM instances.