Maybe internists should worry first. It is easier to teach a computer how to follow patient management algorithms, by far, than to teach it how to read even a simple X-Ray. Which is to say internists should worry about computers taking over their jobs (or at least making all the treatment and management decisions) before radiologists should worry about computers taking over their's. High blood sugar? Okay, a computer can figure that out and then spit out a drug choice. You'd just need thorough nurses to enter all the data in and physical exam findings (not that physical exams actually guide much anymore).
I'm speaking tongue in cheek; I don't think internists need to worry about computers taking over their jobs. Just saying it could happen to them much earlier than it would happen to us.
Radiology is as much art as science, and context plays a large roll. It's not chess or math where the rules are hard and fast and where "right is right". Thus computers can't be expected to master it anytime soon.
Examples: Identical ultrasound findings can mean diametrically opposed things, but with context of comparison X-Ray it can be easily distinguished (emphysematous cholecystitis is a mimic for porcelain gallbladder on ultrasound, for example, but easily distinguishable with correlation). Identical findings can be suggestive of different things depending on clinical history: free air in a seventy-year old with bowel obstruction can relate to perforation, but free air in that same seventy-year old can be normal status post surgery. Free fluid may be normal in a teen girl but is rarely normal in a boy. White matter disease is chronic small vessel disease if you are seventy but may be Lyme, multiple sclerosis or guillain barre in a thirty year old. Etc..