Telethermographic Evidence of Tattoos Dermatological Relevance

A tattoo is a marking made by inserting ink into the layers of skin to change the pigment for decorations or other reasons. Because it requires breaking the skin barrier, tattooing may carry health risks, including infection and allergic reactions and can modify the thermal and optical properties of the skin tissues. The aim of the present work is the definition of appropriate procedures based on computerized convolution filters to evaluate thermographic images of tattooed skin tissues in voluntary subjects, for dermatological aims. In fact, investigating the infrared radiation emitted by skin tissues is of noticeable importance in order to evaluate the dermatological behavior due to under skin microcirculation. In this context, the telethermographic technique, that put in evidence the thermal radiation emitted from cutaneous surfaces, constitutes the proper instrument to enhance tattoos cutaneous effects. In particular, it appears to be very helpful in the evaluation of skin reactions and scars. At the acquired images we have applied the Image Mean Index algorithm to highlight any differences between thermographic images. After that, we have applied the Sobel Operator and Laplacian convolution filter to compute an approximation of the gradient of the image intensity function. It has been our intention to find out any possible alteration in the cutaneous properties that can occur after the tattooing practices. Moreover, it has been possible to evaluate the presence of any skin damages due to such practices through the comparison between the regions of interest, where the tattoo was applied and the contra lateral not tattooed ones, by enhancing thermally anomalous behaviors and determine all the possible changes in skin tissues and their relative nature, either pathological or not.