Bümchen und Häschen sind subjetiv ... dieser längliche weiße Fleck da zwischen TH12 und L1 wäre vergleichsweise objektiv ...

Ist sowas gemeint ?

subjektiv ... objektiv

An MRI/CT scan is looked at objectively, although may never be entirely free of subjective input from different examiners.

Ein Beispiel für den Vorschlag in #6:

The clinical diagnosis of craniosynostosis by means of physical examination forms the basis. .... A three-dimensional CT scan images a craniosynostosis in a reliable way and is the most reliable objective diagnostic method. A standardly performed three-dimensional CT scan to objectivize the deformity is highly recommended for operative planning

Thomson (core.ac.uk)

The authors of the guideline in #7 using 'objectivize' are Dutch. The verb does exist (meaning to view or interpret objectively without the influence of personal feelings or opinions) but, like RES-can " ... I don't think I've ever seen it used in this context (or any context for that matter) ..."

I much prefer her suggestion of "... discussed and considered objectively", which would be in relation to the clinical findings.

The patient is complaining of the typical symptoms of an inguinal hernia. Otherwise, findings are unremarkable.

https://www.collinsdictionary.com/dictionary/...

objectivize in British English

or objectivise 

to cause to be objective

to objectivize his feelings

the claims that role-play exercises 'objectivize' recruitment

The first step in considering an issue is to objectivize it, that is to remove the 'we', and the 'our' and the emotive terms, and to replace them with objective factual equivalents. 

objectivize in American English

objectify

to cause to become concrete or objective; objectify

 Also (esp. Brit.): objectivise

objectify in British English

(transitive)to represent concretely; present as an object

 Also: objectivate

objectify in American English

to give objective form to; make objective or concrete; externalize

to present as an object, esp. of sight, touch, or other physical sense; make objective; externalize

objectivate in British English

another word for objectify

Für objectivize, objectify und objectivate hat Collins keine deutsche Übersetzung ...

Back to the basic question in the OP: Do we use "objectify" like this in English?

IMHO the answer is still "no", and "objectivize" as given in all the definitions in #9 doesn't fit the context either.

You can objectivise feelings or objectivise an abstract concept by presenting it as a work of art. In the example given in #7, it is the deformity that is being "objectivised" by a CT scan, not the CT scan itself.

In the OP: die MRT Bilder besprochen und objektiviert. The normal anatomy and any pathological changes (in the groin or wherever) are being objectivised by the MRI scan. The MRI images themselves are not being objectivised, they are being discussed and looked at/considered objectively in the light of the clinical picture.