Browse evidence-based analysis of health-related claims and assertions
Getting an ultrasound of the thyroid if you have no symptoms doesn’t seem to help people live longer or prevent them from dying of thyroid cancer, according to a study in Korea.
Correlational
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.
There's no universal rulebook for using full-body MRI scans to check healthy people for cancer, so different hospitals do it differently—making it hard to trust the results or use them widely in doctors' offices.
Descriptive
A special type of full-body scan that doesn’t use radiation can find serious health problems that aren’t cancer—like bulging blood vessels, harmless lumps, liver issues, or lung infections—and sometimes leads doctors to take action.
When doctors didn’t have a regular test to check for cancer, a special full-body MRI scan found cancer in nearly 7 out of 10 people—so it might help catch cancers that other tests miss.
Quantitative
When doctors scanned healthy adults with a full-body MRI just to check for problems, most of the cancers they found were in people who didn’t have any symptoms—meaning the scan caught cancers before people even felt sick.
When people got a full-body MRI scan and then had a biopsy done just to check if something was wrong, more than half of them turned out to have cancer — so the biopsy seems to be a good way to find real cancer cases in this group.
A special type of full-body MRI scan found cancer in 2.2% of healthy or slightly symptomatic adults between 35 and 79, and even more often in people over 65 — suggesting it might catch cancers that regular screenings usually miss.
Doctors are testing a full-body scan that can find many types of cancer at once, and they’re using it on both people who pay for it themselves and those who get it for free, to see if rich and poor people are being detected differently.
Using a full-body MRI scan to look for cancer early might help find cancer sooner and at an earlier stage, which lets doctors better understand how people get diagnosed over time.
Using a full-body MRI scan to check for cancer and other serious health problems might help doctors find them more accurately, based on how often it correctly identifies or rules out disease.
Using a special full-body MRI scan and a new way to sort results, doctors can find serious health problems that aren't cancer—like heart or liver issues—that need quick follow-up.
Using a full-body MRI scan to check for hidden health problems has been linked to finding cancers and other serious conditions in real patients, and doctors use special scoring systems to decide who needs more tests.
When doctors scan healthy people’s whole bodies with MRI, they find cancer in about 1 out of every 80 people—but almost a quarter of those with suspicious findings never get follow-up tests, so we might be missing even more cancers than we think.
Two expert radiologists using the ONCO-RADS system to rate MRI scans agreed on the cancer risk level in nearly all cases — showing the system is consistent and not just based on personal opinion.
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.
If you're an adult with no symptoms, being older, having high blood pressure, carrying hepatitis B, or having had surgery before might mean your full-body MRI shows more suspicious findings that could need further checking.
When healthy adults get a full-body MRI scan, those flagged with higher ONCO-RADS scores (4 or 5) are much more likely to actually have cancer—about 4 in 10 for score 4 and 3 in 4 for score 5.
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.
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.
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.
We don’t have enough solid proof yet to say that scanning the whole body with MRI helps healthy people find problems early or saves money.
Getting a full-body MRI scan if you're not at high risk for disease might find things that aren't actually problems, leading to more tests and stress — and no one has yet measured how often this happens.
Some people think that getting a full-body MRI scan might help find several health problems at once and save you from having to do lots of separate tests — but this hasn’t been proven yet.