Noninvasive assessment of cardiac ischemic injury using Rb-87 and Na-23 MRimaging, P-31 MR, and optical spectroscopy

The aim of the study was to compare and analyze different noninvasive indic es of cell damage in the isolated pig heart model of regional ischemia. We used Na-23 and Rb-87 MR imaging to evaluate Na+/K+ balance, P-31 MR spectro scopy to measure energetics, and optical spectroscopy to assess oxymyoglobi n (MbO(2)). Hearts were subjected to 120-min occlusion of the left anterior descending artery and were then reperfused for 120 min. Reperfusion result ed in an increase in Na-23 (37 +/- 18% of the posterior wall) and decrease in Rb-87 (55 +/- 15%) image intensities, partial recovery of PCr, ATP, the total phosphates, and MbO(2), in the anterior wall. The above changes are c onsistent with the irreversible cell damage in the anterior wall, confirmed by lack of staining with triphenyltetrazolium chloride. Changes in Na+ and Rb+ in the infarct area inversely correlated and their ratio is a more sen sitive index of cell injury than either of them alone. Published 2000 Wiley -Liss, Inc.dagger