That's interesting about the DICOM fields (but we've strayed off topic). I'm a bit (maybe very much) out of date now, but I recall that the various manufacturers of DR equipment seemingly liked to use their own "exposure indexes" (with calibration requirements based upon differing physical factors - as in "physics" - μGy, HVL and what-have-you). Perhaps by now there has been a move towards standardisation.
Which technologies (manufacturers) are you using? I'm guessing Agfa and Fuji.
If I'm reading you correctly, your radiographers have been "cranking up" factors slightly since adopting DR. I'm assuming (hopefully) that patient doses are not unduly affected, as the AEC circuitry should terminate exposures once meaningful images (what we used to have thought of as contrast, or "film blackening") have been obtained. There should be a DICOM field that records actual exposure duration (as well as the current-time product - mAs).
As you probably know, there are many fields (or "Tags") in the DICOM header, including one (0018,115E) that gives patient dose.
DICOMlookup is very useful.
For reference,
these are the DICOM tags you have indicated.
