In vivo near-infrared fluorescence imaging of skin and cutaneous melanin
In this Medical Physics M.Sc. project, a near-infrared (NIR) fluorescence imaging system was built for in-vivo diagnosis and evaluation of pigmented skin abnormalities and diseases. Light coming from a 785 nm diode laser is coupled into a ring light guide to uniformly illuminate the skin surface wit...
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Format: | Others |
Language: | en |
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Vancouver : University of British Columbia
2006
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Online Access: | http://hdl.handle.net/2429/77 |
Summary: | In this Medical Physics M.Sc. project, a near-infrared (NIR) fluorescence imaging system was built for in-vivo diagnosis and evaluation of pigmented skin abnormalities and diseases. Light coming from a 785 nm diode laser is coupled into a ring light guide to uniformly illuminate the skin surface with a field-of-view (FOV) of 25 mm diameter. The diffuse reflectance and emitted fluorescence photons are collected by an NIR-sensitive CCD camera, with computer-controlled filter switch to select between reflectance mode and fluorescence mode. Both reflectance and fluorescence images of skin disorders were obtained with an exposure time of 2 seconds. The results show that cutaneous melanin in pigmented skin disorders emits higher NIR autofluorescence (AF) than surrounding normal tissue. This finding challanged the conventional concept that melanin is a non-fluorescence substance. The developed NIR autofluorescence imaging method also provided a new and direct way to characterize cutaneous melanin and can potentially be used for evaluation and diagnosis of pigmented skin diseases and skin cancers, such as melanoma. |
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