• Question: are there any risks to mri scanning like there are with x-rays?

    Asked by sterry2 to Carolyn on 16 Mar 2010 in Categories: .
    • Photo: Carolyn McGettigan

      Carolyn McGettigan answered on 16 Mar 2010:

      MRI scans have been used in medicine for around 20 years with no known side-effects. The main risks are associated with the fact that the scanner is a giant magnet. So, you shouldn’t go in there with metal in or on your body, particularly if you’re only being scanned for research and not medical treatment. The people who shouldn’t be scanned includes individuals who have medical implants like cardiac pacemakers, aneurysm clips, pins or plates.

      At the imaging centre at UCL we go through several careful checks of our participants so we can be sure they are suitable to go in the scanner. The good thing is that once you’re in there it’s totally ‘non-invasive’ – no injections or anything. Our participants just have to lie still and do our experiment for a while. Some people find the scanner very relaxing indeed – I’ve had to throw away a couple of data sets from participants who fell asleep! One guy I tested even began snoring before the experiment started – that was a bad day ; )

Comments

  • Photo: Joe

    Joe commented on :

    Can I just add to Carolyn’s reply and say that MRI is a very safe technology — much safer than X-rays overall. If you follow the safety guidelines C mentioned, then a person can have as many MRI scans as necessary with no extra safety risks. In fact, we worry about getting lower back ache from lying on your back without moving more than anything from the MRI scanner.

    I can’t even guess how many times I’ve been in an MRI scanner in the last 10 years — I reckon a couple of hundred times. For me the biggest risk is falling asleep but it’s totally worth it because seeing your own brain is fantastic. It’s almost as much as showing someone their own brain for the first time.

  • modshamini commented on :

    What if someone has to have an MRI scan and they’re claustrophobic? :S

  • Photo: Joe

    Joe commented on :

    Hi Shamini,

    That does happen fairly commonly. If they have to have an MRI then it is normally being done for clinical — rather than research — purposes. In that case, they typically are administered a sedative by the consultant to calm them and remove the worst of the claustrophobia. In the worst cases, they might be completely sedated. Either way, this is fine because the doctor is only taking structural pictures of the anatomy and you don’t have to be awake for that.

    When Carolyn and I use MRI scanners, we do functional (rather than structural) scans that allow us to map out what parts of the brain are engaged when a person performs some task (like reading words or solving a problem or whatever). For that, you obviously need to be awake. So if we had a volunteer who was severely claustrophobic, we just wouldn’t test them.

    Cheers.