Is there a way to get the size of a DICOM file before downloading it from DICOMweb?

[psavery]

When retrieving a DICOM instance (via WADO-RS retrieve instance), is it possible to obtain the size of the DICOM file, without having to stream the entire thing?

For instance, I have a local dcm4chee server, and if I run code like this:

import requests
url = 'http://localhost:8008/dcm4chee-arc/aets/DCM4CHEE/rs/studies/2.25.25644321580420796312527343668921514374/series/1.3.6.1.4.1.5962.99.1.3205815762.381594633.1639588388306.2.0/instances/1.3.6.1.4.1.5962.99.1.3205815762.381594633.1639588388306.15.0'
result = requests.get(url, stream=True)

It would be very helpful to know either the DICOM file size, or the number of bytes that will be streamed, before streaming (or after only streaming the header). I don't see a Content-Length in result.headers. Is there another way to know how large the DICOM file is (or how much data will be streamed)? Maybe there is something in the DICOMweb standard I am missing?

For the imaging data commons server, the request does return the content length:

import requests

url = 'https://proxy.imaging.datacommons.cancer.gov/current/viewer-only-no-downloads-see-tinyurl-dot-com-slash-3j3d9jyp/dicomWeb/studies/2.25.227261840503961430496812955999336758586/series/1.3.6.1.4.1.5962.99.1.1334438926.1589741711.1637717011470.2.0/instances/1.3.6.1.4.1.5962.99.1.1334438926.1589741711.1637717011470.36.0'

result = requests.get(url, stream=True)
print(result.headers['Content-Length'])
# '5479856'

I can use the Content-Length, along with the multipart/related boundary size and streaming a little header information in, to figure out exactly how large (in bytes) the DICOM file is, without having to stream the whole thing.

Is there a way to get the DICOM file size in dcm4chee without streaming the whole thing?