If a child gets a whole-body MRI and it comes back negative, there’s a 99.1% chance they don’t have cancer — so doctors can be very confident the child is cancer-free based on this scan.

If a whole-body MRI scan comes back negative, there’s a 99.8% chance you don’t have any new cancer developing in the short term—especially if you didn’t need a biopsy after the scan.

Doctors might be able to use a full-body MRI scan as the first test to find cancer in kids, because one study showed it was good at spotting cancer and not giving false alarms — but this was only done in one hospital.

A special kind of full-body scan called MRI with a specific setting (STIR) can find cancer in kids with very high accuracy—correctly spotting it in almost all cases where it’s there and correctly saying it’s not there when it isn’t.

When healthy adults without symptoms get a full-body MRI scan, about 1 in 100 are found to have early-stage cancer—like in the lungs, kidneys, or prostate—and catching it this early might help treat it better.