Novel Raman signal recovery from deeply buried tissue components

摘要

A program of work has been established to explore the possibility of sampling Raman information from material deeply buried within tissues. Time-gating, spatial offsetting of source and collection (spatially offset Raman spectroscopy) and transmission approaches have been explored. This invited contribution will outline these and the limitations of each technique will be discussed. Time-gating allows well defined depth selection, but with low penetrations of the order of 1-2mm; whereas SORS has allowed some depth selection and an order of magnitude greater depth range; the use of transmission Raman spectroscopy has permitted greater depths of penetration, but depth selection is not possible in this configuration. To date transmission Raman has demonstrated recovery of compositional information through 27mm of mammalian tissue. Furthermore, a first demonstration of Kerr-gated Raman spectroscopy for fluorescence suppression in resonance Raman measurements of liver and kidney is also outlined.