Finite element analysis of thermal and acoustic processes during laser tattoo removal.

Background And Objective: Q-switched laser therapy is commonly used for the removal of tattoos. However, despite ever increasing demand for this intervention, a better understanding of the mechanisms that result in pigment reduction is required in order to optimise outcomes and reduce the number of treatment episodes.

Study Design: A finite element analysis computer simulation was developed to model the fragmentation response of ink granules during irradiation of a professional black tattoo using a Q-switched Nd:YAG laser.

Determination of the thermal and physical properties of black tattoo ink using compound analysis.

Despite the widespread use of laser therapy in the removal of tattoos, comparatively little is known about its mechanism of action. There is a need for an improved understanding of the composition and thermal properties of the tattoo ink in order that simulations of laser therapy may be better informed and treatment parameters optimised. Scanning electron microscopy and time-of-flight secondary ion mass spectrometry identified that the relative proportions of the constituent compounds of the ink likely to exist in vivo are the following: carbon black pigment (89 %), carvacrol (5 %), eugenol (2 %), hexenol (3 %) and propylene glycol (1 %).

Adverse effects following Q-switched ruby laser treatment of pigmented lesions.

A retrospective study was conducted to investigate the incidence of adverse effects following Q-switched ruby laser treatment of pigmented lesions at the Wessex Specialist Laser Centre. Sixty-one patients received a total of 151 treatments between January 2006 and January 2008. This is the largest series to date of patients on whom adverse effects have been reported following Q-switched ruby laser treatment of an assortment of pigmented lesions.