It’s typically four years of undergraduate study, four years of medical school, one year of general internship such as internal medicine and 4 years of radiology residency. There are fellowship options after that for subspecialization.
More subjectively, it is a field with little patient contact and more contact with referring physicians to discuss their patients studies. It is computer based and encompasses most other fields of medicine, so every day is diverse and interesting. Radiology is a pillar of any hospital, guiding patient treatment in many cases. It requires attention to detail and an in-depth knowledge of anatomy and disease processes.
I couldn't say much about the medical requirements, but from a radiation physicist's point of view, I can say radiologists would need to be comfortable working with ionising radiation and will need a good mathematical understanding to deal with dose measurements and converting between different units.