Detection of skin abnormalities using confocal Raman microspectroscopy

Skin cancers are the most numerous of all human cancers. Yet despite their easy accessibility to diagnostic methods, clinicians rely on biopsy and histopathologic validation for positive diagnosis. Raman spectroscopy is an optical technique that has been shown to provide diagnostic ability rivaling or exceeding that of histopathologic examination. This work evaluated the utility of depth-resolved confocal Raman spectroscopy for skin cancer diagnosis. Processing techniques were developed to automatically eliminate inherent fluorescence background noise. A bench-top confocal Raman microscope (CRM) was developed using an external-cavity diode laser to allow system portability. This system was used to classify malignant skin lesions in vitro with high accuracy. Based on this success, a handheld CRM was developed for clinical measurements of suspected nonmelanoma skin cancers. Raman spectra obtained with this system were able to completely differentiate skin lesions. The findings of this work reveals confocal Raman spectroscopy to be a viable tool for clinical diagnosis of skin lesions.