Experimental acute pancreatitis: MR relaxation time studies using gadolinium–DTPA

Spin-lattice (T1) and spin-spin (T2) relaxation times of normal and sodium taurocholate-induced pancreatitis (38 rats) were determined in vitro using a 10.7-MHz magnetic resonance (MR) spectrometer. The increase in pancreatic T1 time in acute hemorrhagic pancreatitis correlated well with the elevated water content of the organ. Gadolinium-DTPA did not affect significantly the relaxation times of normal pancreas in vitro during 1 t 20 min postinjection, but it decreased the elevated T1 times of inflamed pancreas almost to baseline values. MR imaging studies of rat pancreas in vivo (8 rats, 0.35-T resistive magnet) indicated that the swollen pancreas and associated edema were depicted using a T2-weighted SE sequence. Fifteen minutes postinjection of gadolinium-DTPA a homogeneous enhancement of inflamed pancreas was detected. The differentiation of pancreatic necrotic foci from surrounding viable tissue and edema could not be detected on Gd-DTPA-enhanced MR images after 15 min postinjection although microscopical workup indicated these different tissue constituents in the pancreas.