Well I did say the actual calculations would be (and are) more complicated. And as I said, short of availability constraints, the MRI itself isn't an issue, it

Well I did say the actual calculations would be (and are) more complicated. And as I said, short of availability constraints, the MRI itself isn't an issue, it's the follow up. Ignoring the fact that in the real world due to constraints this isn't really a local optimization, if we assume infinite availability you still have a problem that low sensitivity tests lead to excess unnecessary work up risks. Your assertion that it is always easy to get good information leading to correct choices here is just incorrect and probably naive. The trade offs you are talking about are very well known and have been studied by professionals for decades; none of them will claim it easy - for good reasons. Note I'm not appealing to authority here. Many people can educate themselves to the degree that in a narrow area of their own healthcare they are as or more knowledgable than the average professional. However, this is not at all easy, and will require a ton of work. The cost benefit for a lot of screening etc. just isn't there; for a particularly symptomatic disease it may well be.