Disagree with f_w's bogus PC answer.
In general, radiologists tend to be smarter than many other docs -- I mean higher IQs and more street smarts/worldy knowledge. They are definitely more well rounded than most other docs. Radiologists are ambitious and success-driven. They are socially adept, articulate, and amiable. The whole if-you're-good-with-people-go-into-medicine and if-not-go-into-radiology thing is TOTALLY WRONG. Think about it: In medicine you have to deal with uneducated, illiterate derelicts and scumbags (i.e. patients) and low level ancillary staff (i.e. nurses). In radiology you are in constant communication with fellow physicians. Which one do you think requires superior communication skills?
What else? Oh yeah we are very self confident and self assured -- we picked the best gig in medicine, we earn near the top, and all other specialties envy us so we should be. You can definitely be introverted and do GREAT in rads... I too am somewhat schizoid and love working/thinking alone -- but if/when you want you can get tons of meaningful interaction with colleagues and (if you really want) patients too. Smooth talkers? Heck I don't know... all specialties have those -- rads is no exception.
In rads I think it's important to be somewhat self-motivated -- ideally one should be a philomath -- b/c you do have to read and learn constantly. Being a technophile helps but is not an absolute requirement.
There's probably a ton more but those are a few off the top of my head. Rads rules. Don't think -- do rads.
peace