Raman imaging of large-area human tissue

Raman spectroscopy has been successfully applied to medical applications and emerged as a powerful non-invasive technique able to provide information to identify tissue diseases and guiding during image surgery. Of particular interest for medical diagnosis are Raman images in which a complete Raman spectrum is acquired for each pixel of the image enabling the generation of chemical maps. However, Raman images are usually recorded in a time consuming step-by-step scanning process that may take several minutes or even hours. Integral field Spectroscopy (IFS) is a technique used in Astronomy that reduces the recording time by combining imaging and spectroscopic capabilities in a single instrument. Both, spatial and spectral information are provided simultaneously without scanning procedure and with outstanding light collection efficiency [1]. IFS is based on slicing the image using a mirror stack or a bundle of optical fibers and stringing the slices together in front of the slit of a multiplex spectrograph. Raman SERDS (Shifted Excitation Raman Differential Spectroscopy) images of large-area porcine skin patches and the basic principles for a pseudo-real-time video Raman imaging have already been reported using this technique [2].