04 April 2011

MRI - Metal Screening


Before every MRI we screen our patients for possible metal foreign bodies. Those can be implanted due to prior medical procedures as well as accidental. One of the specific inquiry concerns possible metal foreign bodies in the orbit. Sometimes patients work with metal and indicate possibility of being exposed to small projectile metal particles. In such case we check prior CT examinations for possible metal foreign bodies. Note above case of a small piece of metal located medially and superiorly in the left orbit. Here metal seems not to be attached to the globe. However due to risk of metal motion in strong magnetic field of the MRI scanner in a case like this we ask for ophthalmologist consultation. One should review scanogram as well as thin slices of the CT - considering size of foreign body and slice thickness. In case we do not have prior CT we order x-ray of the orbits.