There are many different medical situations and injuries that require a radiologist, and it is one of our most crucial technologies for assessing injury. That means job security is fairly high. As far as being in a high paying medical field, this is a great path for those who can't see themselves sticking anyone with a needle, or performing heart surgery. That isn't to say being a radiologist is easy, but you won't be cutting into anyone's skin.
First you'll need to go to medical school, but then you'll need to do four years of radiology training. That's quite a bit of schooling but it's what's necessary when your job is to not only use expensive equipment but also to assess the photographs taken. A radiologist is no good if they can't assess the images they take.