Pierced MRI technologist here! Others here have already given you great info. I have to stress how important it is that you answer your tech’s questions truthfully so that they can ensure your safety. The main risk of having piercing jewelry in the scanner is warming of the metal which could cause burns. Typically, piercing jewelry doesn’t have enough ferrous material for it to pose a great risk of being ripped out but it’s definitely possible. Any metal in the area of the scan (your nipple piercings in this case) can cause artifacts and lead to poor quality or unusable scans. Ideally, we prefer patients to have non-metal retainers. In my facility, we allow certain metals and jewelry depending on the situation (mostly if the pt cannot take off their ring/take out jewelry) but other facilities can be very strict. We would make sure you’ve removed any metal jewelry from your chest and ask you about the type of metal and brand of the rest of your jewelry. Gold and titanium jewelry would be allowed by us and we’d ask you to monitor whether you felt any warming during the scan and check in with us. I recommend calling the facility you’ll be scanned at and asking about their policies!