Eissa N. E. AguorCees W. A. van de KolkFatih Arslan • Marcel G. J. NederhoffPieter A. F. M. Doevendans • Gerard PasterkampGustav J. StrijkersCees J. A. van Echteld

Myocardial edema can arise in several disease states. MRI contrast agent can accumulate in edematous tis- sue, which complicates differential diagnosis with contrast- enhanced (CE)-MRI and might lead to overestimation of infarct size. Sodium Chemical Shift Imaging ( 23 Na-CSI) may provide an alternative for edema imaging. We have developed a non-infarct, isolated rat heart model with two levels of edema, which was studied with 23 Na-CSI and CE-MRI. In edematous, but viable tissue the extracellular sodium (Nae ) signal is hypothesized to increase, but not the intracellular sodium (Nai ) signal. Isolated hearts were perfused at 60 (n = 6) and 140 mmHg (n = 5). Dimethyl methylphos- phonate (DMMP) and phenylphosphonate (PPA) were used to follow edema formation by 31 P-MR Spectroscopy. In separate groups, Thulium(III)1,4,7,10 tetraazacyclododecane- N,N 0 ,N 00 ,N 000 -tetra(methylenephosphonate) (TmDOTP 5- )a nd