Since the subject and verb have to be in agreement, I'm assuming that the singular verb ("is") should be used in the following sentence:

The chest x-ray, along with the other studies, is consistent with chronic obstructive pulmonary disease.

Is this correct?

Thanks for the help, as usual!
It is. In this case X-ray refers to the electromagnetic radiation.
Yes, "is" is correct because it's a singular subject "x-ray".

"other studies" aren't part of the subject, because "along with" makes them subordinate. You need a co-ordinate conjunction (usually "and") to make a combined subject that would take a plural verb.

The chest x-ray is consistent (along with the other studies) ...


The chest x-ray and other studies are consistent with ....