In vivo near-infrared autofluorescence imaging of pigmented skin lesions: methods, technical improvements and preliminary clinical results
Article first published online: 22 JUN 2012
© 2012 John Wiley & Sons A/S
Skin Research and Technology
Volume 19, Issue 1, pages 20–26, February 2013
How to Cite
Wang, S., Zhao, J., Lui, H., He, Q. and Zeng, H. (2013), In vivo near-infrared autofluorescence imaging of pigmented skin lesions: methods, technical improvements and preliminary clinical results. Skin Research and Technology, 19: 20–26. doi: 10.1111/j.1600-0846.2012.00632.x
- Issue published online: 7 JAN 2013
- Article first published online: 22 JUN 2012
- Manuscript Accepted: 26 APR 2012
- near infrared autofluorescence imaging;
- pigmented skin lesion;
Fluorescence emission from in vivo cutaneous melanin was recently detected under near-infrared (NIR) excitation by our group. We then built a prototype NIR autofluorescence imaging system to observe and characterize the melanin distribution in human skin. In this article, we reported a new setup of NIR fluorescence imaging system and calibration methods to optimize the system for better clinical feasibility and clearer image.
The imaging system was designed to perform both fluorescence and reflectance imaging with a 785-nm fiber-coupled laser source. The illumination light was purified by a 785-nm bandpass filter for fluorescence excitation; while the spontaneous components were selected by a longpass filter for NIR reflectance imaging. A hand-controlled filter wheel was used to switch these two filters for different imaging modes. A dichroic filter was used to guide the illuminating light onto the skin surface for excitation. Reflectance and fluorescence signals were collected sequentially by a NIR optimized CCD camera. The captured images were calibrated by the reflectance images of a standard reflectance disk for non-uniform illuminations and light collection efficiencies.
The clinical results demonstrated that NIR fluorescence intensities and distribution patterns vary among lesion types. It was also confirmed that pigmented skin lesions emitted higher NIR fluorescence than the surrounding normal skin due to the presentation of higher concentrations of cutaneous melanin within the lesions.
NIR autofluorescence imaging system could be utilized as a powerful tool for visualizing melanin distribution in pigmented skin lesions and as a potential method for aiding melanoma detection.