The radiologist is a physician specialist, and ordering an imaging study is requesting their consultation. If I send you for a study, I indicate the problem, and briefly what I want them to look for, or what question I want answered.
In response, the radiologist will a)agree that the study I ordered was the appropriate one, or suggest a different study; b)write a report which hopefully will answer the question I posed; and c)indicate anything else which can be gleaned from the study, often unrelated to the question at hand. He/she will also review other "pertinent normals".
MANY times over the years I received a report of unrelated findings.
I highly doubt that the practice of radiology varies significantly between countries.
Finally, in the USA, they are vastly overpaid (!)