ON THE CORRELATION BETWEEN TISSUE HYDRATION STATE AND PROTON NMR RELAXATION RATES IN EXPERIMENTAL LIVER-TRANSPLANTATION

As the tissue hydration state is one of the most important parameters to predict viability cold stored livers before transplantation, we inv estigated the correlation between the tissue inverse total water fract ion, reflecting the hydration state, and proton relaxation times in co ld stored rat liver and orthotopic liver transplantation in a pig mode l. In cold stored rat liver excellent linear correlations between rela xation rates R-1 (=1/T-1) and R-2 (=1/T-2) and inverse total water fra ction 1/P-w were obtained. In pig liver transplants, the slope and int ercept obtained from a linear regression model are twice as high for R -1 and almost identical for R-2; however, correlation coefficients are lower due to increased biological variation and a smaller range in st orage conditions, reflected by the range of water content, Proton nucl ear magnetic resonance relaxation times measured during the cold stora ge on the whole organ non-invasively show also linear correlation with the inverse total water fraction, but the method is presently not acc urate enough to estimate the hydration state of the liver tissue with sufficient precision, NMR relaxation times obtained from liver biopsie s have the potential to predict tissue viability in experimental fiver transplantation independent of species, strain and gender, and thus m ay be useful in estimating the viability of human donor livers (or at least add a new complementary information to the information gained by standard liver selection and function test before and after transplan tation). (C) 1997 John Wiley & Sons, Ltd,