Odds of Getting In
The job outlook for radiologists is very good. It's an in-demand field right now and is expected to grow much faster than the rest of the job market (source).
That said, you should aim to be at the top of your class if you want to get in on this career. Residency programs are becoming more and more competitive all the time. If you've got the kind of ambition it takes to climb to the top of your med school classes, it'll be smooth sailing the rest of the way—so long as you always, always keep up with that work ethic.