But how do you know the unnecessary treatment isn’t necessary? There is likely always something happening in your body that would suggest an unnecessary treatment. So if you start doing scans when you have no outward reason to, you’ll always find something that looks like it needs treatment.
There’s no perfect information in medicine.
The more scans you do, the more times you’ll make the wrong choice and unnecessarily treat something.
Well, first of all, if it were possible to do these scans on everyone, we would be able to better study what things that show up actually do benefit from treatment, and which are better to ignore.
Absent that, it would be a matter of judgment. Some people do get fairly extensive annual physical exams, so there is data out there. For each issue the scan found, it would be a matter of researching and making a judgment call on whether the risk/benefit weighs toward action. I would prefer to make those decisions with as much information as possible vs just remaining ignorant and hoping the things I don't know about are best left alone.