Just a little FYI on MRI. MRI stands for Magnetic Resonance Imaging. The main word being magnetic. That being said, when an MRI technologist asks you to remove all metal objects and electronic devices from your person it does not mean put them in your pocket or attach them to you belt loop. Why you ask? Because it is a powerful magnet. To put it in perspective. The earth's magnetic field is .5 Gauss. The magnet strength of a typical MRI unit is 1.5 Tesla. 1 Tesla=10,000 Gauss. It will suck the ferrous item right out of your hand. We techs call it the missile effect. Because the objects become projectiles in the room.
To sum up. When an MRI tech asks you to take everything out of your pockets. That doesn't mean leave the nail clippers in there. And it certainly doesn't mean leave the toy BB gun that you just confiscated from your son.