The potential for histological screening using a combination of rapid Raman mapping and principal component analysis

Rapid Raman mapping was carried out on 20 mu m sections of oesophagel biopsy samples. Contiguous 7 mu m sections were stained with haematoxylin and eosin (H&E)with histopathology provided by an expert pathologist. The step size and acquisition times were varied and the resulting spectra, principal component (PC) score maps and loads were compared. Overall mapping times were also compared to traditional Raman point mapping. The principal component loads for each of the maps were seen to be similar despite varying the acqusition time and number of spectra. Gross biochemics information was extracted showing good correlaties with the H&B sections even for short overall mapping times (30-90 minutes for a 2mm biopsy, 0.5 s acqusition time per 25.3 mu m Raman pixel). This demostrates that low signal to noise spectral maps are sufficient for the identification of histologically relevant biochemistry using principal component analysis as long as the spectral dataset is large enough. (c) 2009 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim