No, oftentimes they will intentionality constrain the scan to a specific area that they’re interested in. This limits the time and cost. However there are prett

No, oftentimes they will intentionality constrain the scan to a specific area that they’re interested in. This limits the time and cost. However there are pretty consistent scan procedures, eg they might order a “sacral MRI” for lower back issues. As others have mentioned, full body MRIs may be used for cancer that they’re concerned may have metastasized. The reluctance of people to do this is that it’s kind of “going fishing”. If they spot something weird, they may wind up having to follow up on it even if it’s probably benign. They don’t want you to come back a few years down the road and hold them responsible for not looking into an ambiguous blotch on an MRI that turned out to be cancerous rather than benign. It’s not really scalable. Someone on here did mention the idea of starting a program of doing full body scans of everybody and then building a database of what things turned out to be an issue to build a better automatic early detection system. It’s an interesting idea. That being said, having an MRI really sucks. You put on ear protection and have to lay still for dozens of minutes or hours while the machine clicks, beeps, clunks, and buzzes at ear-splitting volumes (hence the ear protection). And since an MRI acts as a huge magnet, you can’t take headphones in with you. There was one or two places I went that had non-metallic ear phones, but this seems to be exception rather than the norm. Contrast means getting an injection partway through. And even if you’ve never had problems with claustrophobia, MRIs can still trigger it (there are open MRIs, but these may compromise on resolution). So it’s very understandable that a reasonable amount of effort is made to minimize MRI time.