Laser tattoo removal is a successful application of the theory of selective photothermolysis (SPTL). However, unlike treatments for blood vessels or hair the mechanism required to shatter tattoo particles uses the photomechanical effect. In this situation the energy is absorbed by the ink particles in a very short time, typically nanoseconds. The surface temperature of the ink particles can rise to thousands of degrees but this energy profile rapidly collapses into a shock wave. This shock wave then propagates throughout the local tissue (the dermis) causing brittle structures to fragment. Hence tissues are largely unaffected since they simply vibrate as the shock wave passes. For laser tattoo removal the selective destruction of tattoo pigments depends on four factors:
The Kirby-Desai Scale assigns numerical values to six parameters: skin type, location, color, amount of ink, scarring or tissue change, and layering. Parameter scores are then added to yield a combined score that will show the estimated number of treatments needed for successful tattoo removal. Experts recommend that the Kirby-Desai scale be used by all laser practitioners prior to starting tattoo removal treatment to help determine the number of treatments required for tattoo removal and as a predictor of the success of the laser tattoo removal treatments. Prior to 2009, clinicians had no scientific basis by which to estimate the number of treatments needed to remove a tattoo and the use of this scale is now standard practice in laser tattoo removal.
In the early 1980s, a new clinical study began in Canniesburn Hospital's Burns and Plastic Surgery Unit, in Glasgow, Scotland, into the effects of Q-switched ruby laser energy on blue/black tattoos. Further studies into other tattoo colours were then carried out with various degrees of success. Research at the University of Strathclyde, Glasgow also showed that there was no detectable mutagenicity in tissues following irradiation with the Q-switched ruby laser. This essentially shows that the treatment is safe, from a biological viewpoint, with no detectable risk of the development of cancerous cells.
Card symbols have long been popular symbols to get inked. The ace of spades is usually the most popular one to get but not far behind are the Queens. The queen of clubs symbolises a strong willed and positive person. Tattoos in between the fingers usually need to get redone every few years as they do fade due to the amount of rubbing that occurs there.