Imaging of Human Skin Lesions Using Multipixel Fourier Transform Spectroscopy Fourier Transform Spectral Imaging

A novel spectral image-analysis system based on Fourier transformed spectroscopy combined with image processing has been used for the in vivo study of porphyrin localisation in human skin lesions. Fluorescence measurements were performed on patients with basal cell carcinomas (BCC) and acne. BCC lesions were examined after a 16-hour topical application of aminolaevulinic acid (ALA); for acne lesions, autofluorescence was studied. The results of fluorescence microscopy of BCC lesions revealed red fluorescence in the stratum corneum, epidermis, pilosebaceous units and in the tumour sites. The in vivo macroscopic examination showed higher protoporphyrin IX (PP) fluorescence in BCC lesions and in acne as compared to the surrounding normal tissue. An enhanced demarcation of the lesions' borders was obtained using the spectral similarity-mapping function.