About fMRI
This page borrows heavily from that which appears on Dr. Jody Culham's lab website. Dr. Culham is a true innovator in the field, and her expertise in neuroimaging has benefitted many fMRI researchers. She is also the creator of the 'fMRI 4 Newbies' website, an invaluable source of information for anyone interested in functional MRI.
Is it safe?
MRI scans have been performed around the world for many years, with very few incidents occurring. Although being exposed to a magnetic field of this strength has no effect on biological tissue, it is important to ensure no ferromagnetic objects enter the scanner room. Also, metal that is implanted in your body (like a pacemaker or aneurysm clip) may malfunction in these conditions. Therefore, it is critical that you fully comply with all safety procedures and answer screening questions honestly and accurately.
If it is determined you meet eligibility requirements, here are some things to keep in mind.
The day of the scan:
- If applicable, remember to wear contact lenses instead of glasses.
- Do not drink excessive amounts of liquid, especially caffeine, before the scan.
- Do not wear any clothing with metal around the head, such as a shirt with a metal zipper. Metal buttons and zippers on pants are generally okay.
- Do not use any hairclips and be prepared to remove jewellery and piercings.
- For women, if possible, do not wear an underwire bra (the metal can throw off the magnetic field). Sports bras are an fMRI compatible alternative.
- Avoid wearing mascara (can contain metal flakes), hair gel (can throw off magnet signal) and arriving to the scan with wet hair.
- Make sure you know where you are going to meet the experimenter and what time you are expected to show up. If you have to cancel, provide as much notice as possible.
While in the magnet:
- Make sure you are comfortable while lying in the scanner. Anything that is slightly uncomfortable at the start of the scan will feel much worse by the end.
- As the bed is moving into the center of the bore, you may start to feel dizzy. This is entirely normal and should subside once you are in place. Let the experimenters know if it does not.
- Try not to change head or body position while the magnet is beeping. The position of body parts in the magnetic field distorts it. So if you cross your legs, scratch your head, open your mouth, yawn (inhale deeply), or shift your posture, it can lead to artifacts even if your brain doesn't move.
- Swallowing can lead to head motion artifacts. If you can avoid swallowing during a scan, the data quality will be better. If trying not to swallow makes you gag or swallow suddenly, then it's best to just swallow normally.
- Try to stay relaxed throughout the session. If you tense up at the beginning of a scan, your head can drift as you settle down.
- You will be given a squeeze ball in case you need to stop the scan midway. You can use this if something goes wrong with the stimuli or if you need to stop immediately
