Discrimination and classification of liver cancer cells and proliferation states by Raman spectroscopic imaging.

Discrimination of nodular lesions in cirrhotic liver is a challenge in the histopathologic diagnostics. For this reason, there is an urgent need for new detection methods to improve the accuracy of the diagnosis of liver cancer. Raman imaging allows to determine the spatial distribution of a variety of molecules in cells or tissue label-free and to correlate this molecular information with the morphological structures at the same sample location. This study reports investigations of two liver cancer cell lines, - HepG2 and SK-Hep1, - as well as HepG2 cells in different cellular growth phases using Raman micro-spectroscopic imaging. Spectral data of all cells were recorded as a color-coded image and subsequentially analyzed by hierarchical cluster and principal component analysis. A support vector machine-based classification algorithm reliably predicts previously unknown cancer cells and cell cycle phases. By including selectively the Raman spectra of the cytoplasmic lipids in the classifier, the accuracy has been improved. The main spectral differences that were found in the comparative analysis can be attributed to a higher expression of unsaturated fatty acids in the hepatocellular carcinoma cells and during the proliferation phase. This corresponds to the already examined de novo lipogenesis in cells of liver cancer.

Color Doppler sonographic dynamic tissue perfusion measurement demonstrates significantly reduced cortical perfusion in children with diabetes mellitus type 1 without microalbuminuria and apparently healthy kidneys.

MOTIVATION: With respect to the devastating consequences of the increasing prevalence of diabetes mellitus, the main reason for end stage renal disease and dialysis in industrialized countries, and the very limited diagnostic and therapeutic possibilities to predict, monitor and prevent diabetic nephropathy (DN), new concepts for early recognition and quantification of the prevailing microvascular changes in DN are urgently needed. MATERIALS AND METHODS: We present the first study of renal cortical tissue perfusion measurement by means of standardized color Doppler sonographic videos evaluated with the PixelFlux software 1 for Dynamic Tissue Perfusion Measurement (DTPM) in 92 patients with DM1 without MA compared to 71 healthy probands. RESULTS: DTPM reveals a highly significant diminution of cortical perfusion in patients with DM1 compared to healthy probands by 31 %, most pronounced in the distal hemicortex (reduction by 50 %) compared to 21 % within the proximal hemicortex. CONCLUSION: Thus, DTPM offers a novel means of numerically describing the state of the renal microvasculature in DM in a patient-friendly, non-invasive, non-ionizing manner.