When doctors tell patients about unexpected findings on a full-body MRI scan, it leads to over three times more biopsies that find cancer—but even then, very few actual cancers are found, so it might not be worth the hassle and cost.

When people are told about unexpected findings from a full-body MRI scan, they’re much more likely to get unnecessary biopsies that turn out to be harmless — meaning doctors might be doing too many tests that don’t find cancer.

When people get full-body scans or lab tests and are told about unexpected results—even if those results might not mean anything—they end up getting more biopsies, especially when the scan findings are shared. This might lead to too many medical tests that aren’t really needed.

When people who feel fine get a full-body MRI scan, they often find weird little things that aren’t cancer—but those weird finds happen more often than actual cancers are discovered.

When doctors tell patients about unexpected lab results, it leads to 37% more biopsies—but even more biopsies happen when doctors share unexpected MRI results, meaning imaging scans seem to trigger more follow-up tests than blood tests.

When doctors scan someone’s whole body for research, they sometimes find unexpected things — and more than half the time, they can’t tell if those things are harmless or dangerous without doing more tests.