Huzaira Misbah, Anderson R Rox
Wellman Labs of Photomedicine, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St., Boston, Massachusetts 02114, USA.
Lasers Surg Med. 2002;31(2):121-8. doi: 10.1002/lsm.10075.
Tattoo removal is a significant problem. The extraction of magnetite (Fe(3)O(4)) ink tattoos by a magnetic field was investigated, with and without Q-switched laser treatment.
STUDY DESIGN/MATERIALS AND METHODS: Magnetite particles (1.4 microm) were used to make mature, black skin tattoos on hairless albino rats. A Q-switched ruby laser (QSRL) 3.5 J/cm(2), 6.5-mm spot size, 40-nanosecond pulse width was used for treatment. Permanent magnets (1.4 T, 6-mm diameter) were tested to extract the magnetite particles, alone and after QSRL. Lightening of treated tattoos was measured from digital photographs, and the amount and distribution of magnetite in skin biopsies was scored blindly.
External application of magnets on mature magnetite tattoos without prior QSRL treatment, did not significantly extract, lighten, darken, or change their histologic appearance. A magnetic field applied immediately after QSRL treatment extracted some ink when epidermal injury was present, and caused significant redistribution of magnetite into the upper dermis with vertical banding along magnetic field lines. When applied for 3 weeks following QSRL, magnets caused darkening of tattoos.
Magnetite skin tattoos can be manipulated by external magnets, especially after Q-switched laser treatment. Magnetically-extractable tattoos may be feasible.
纹身去除是一个重要问题。研究了在有或没有调Q激光治疗的情况下，通过磁场提取磁铁矿（Fe(3)O(4)）墨水纹身。
研究设计/材料与方法：使用磁铁矿颗粒（1.4微米）在无毛白化大鼠身上制作成熟的黑色皮肤纹身。使用调Q红宝石激光（QSRL），能量密度为3.5 J/cm(2)，光斑尺寸为6.5毫米，脉冲宽度为40纳秒进行治疗。测试了永磁体（1.4特斯拉，直径6毫米）单独以及在QSRL治疗后提取磁铁矿颗粒的效果。从数码照片测量治疗后纹身的变浅情况，并对皮肤活检中磁铁矿的数量和分布进行盲法评分。
在未进行QSRL预处理的成熟磁铁矿纹身上外用磁体，并未显著提取、变浅、加深或改变其组织学外观。在QSRL治疗后立即施加磁场，当存在表皮损伤时可提取一些墨水，并导致磁铁矿显著重新分布到真皮上层，沿磁力线呈垂直条纹状。在QSRL治疗后施加3周磁体，会导致纹身颜色加深。
磁铁矿皮肤纹身可通过外部磁体进行操控，尤其是在调Q激光治疗后。可磁提取的纹身可能是可行的。
