Could this data be anonymized and open-sourced for training diagnostic algorithms? It’s hard to put the genie back in the bottle so why not at least make some use of the images?
See https://www.cancerimagingarchive.net/ for some examples of carefully curated data.
How much is the data worth for machine learning if you do not have access to the interpretation (and annotations) for the data? That is the hard part.
But. Is it ethical or even legal to do so without patient consent? No (at least not in my country).
The de-id part was actually really easy since DICOM is a very standardized format and this hospital system had good practices in place to only input certain information about each patient.