Aims and objectives
In the past years many Authors have claimed that skin tattoos might expose patients to safety issues related to thermic effects of inks,
when undergoing MRI examinations.
However,
as it is thought that,
after an initial phase from tattoo deposition,
the solvent tends to evaporate,
the most appropriate parameters to take into account when analyzing the thermic effects of tattoos appear to be the ones of pigments alone.
The pigments are injected into the dermis forming a layer which,
after solvent’s evaporation,
is estimated to...
Methods and materials
Five commercial tattoo inks of different colorations (black,
blue,
red,
yellow,
white) were subjected to measurement of electric and magnetic parameters and were then let dry,
in order to measure the same parameters on pigments alone.
The electric conductivity measurement on liquid inks was carried out through an “Agilent” electrical impedance analyzer combined with a "16452A Liquid Test Fixture".
The 16452A employs the parallel plate method,
which sandwiches the liquid material between two electrodes to form a capacitor.
An impedance analyzer is then used to...
Results
The examined inks do not present any significant magnetic properties and show,
at the relevant frequency,
a predominantly conducting behaviour.
In electromagnetic simulations a SAR increment in the tattooed area is noticed,
due to an electric conductivity slightly higher than the one of the tissues.
The temperature increase from the physiological value was nevertheless comparable to the one obtained in the absence of the tattoo.
Conclusion
Although the analysis was carried out in the intent of exasperating some possible thermic effect of tattoos,
limitedly to examined inks the results exclude the onset of abnormal heating during MR scans.
References
Chemical Substances in Tattoo Ink: Survey of chemical substances in consumer products (Kortlægning af kemiske stoffer i forbrugerprodukter) no.
116,
2012