Guarding against overexposure to radiation

I'm happy to see radiologists talking about strategies to minimize radiation exposure in these articles: Strategies for reducing 'dose creep' in digital x-ray and Study suggests ways to cut CR radiation.Most patients have no idea how much radiation they've been exposed to and their doctors don't know either. I've always thought one of the useful elements of a personal health record would be a radiation exposure diary to measure cumulative dose. These articles are about digital X-ray, but CT is a bigger problem.