MR scanning, tattoo inks, and risk of thermal burn: An experimental study of iron oxide and organic pigments: Effect on temperature and magnetic behavior referenced to chemical analysis.

Background: Tattooed persons examined with magnetic resonance imaging (MRI) can develop burning sensation suggested in the literature to be thermal burn from the procedure. MRI-induced thermal effect and magnetic behavior of known tattoo pigments were examined ex vivo. Materials and Methods: Magnetic resonance imaging effects on 3 commonly used commercial ink stock products marketed for cosmetic tattooing was studied. A main study tested 22 formulations based on 11 pigment raw materials, for example, one line of 11 called pastes and another called dispersions. Samples were spread in petri dishes and tested with a 0.97 T neodymium solid magnet to observe visual magnetic behavior. Before MRI, the surface temperature of the ink was measured using an infrared probe. Samples were placed in a clinical 3T scanner. Two scans were performed, that is, one in the isocenter and one 30cm away from the center. After scanning, the surface temperature was measured again. Chemical analysis of samples was performed by mass spectroscopy. Results: Mean temperature increase measured in the isocenter ranged between 0.14 and 0.26 degrees C (P<.01) and in the off-center position from -0.16 to 0.21 degrees C (P<.01). Such low increase of temperature is clinically irrelevant. Chemical analysis showed high concentrations of iron, but also nickel and chrome were found as contaminants. High concentration of iron was not associated with any increase of temperature or any physical draw or move of ink. Conclusion: The study could not confirm any clinically relevant temperature increase of tattoo pigments after MRI.