SPATIALLY LOCALIZED P-31 NMR MEASUREMENTS OF LONGITUDINAL RELAXATION RATES IN THE CANINE MYOCARDIUM

FLAX-ISIS spatial localization was combined with inversion recovery to enable the measurement of spatially localized T1 values. This approac h was applied to the transmural determination of creatine phosphate lo ngitudinal relaxation times in the canine myocardium. By examining fiv e voxels spanning the left myocardial wall, we observed that transmura l T1 values for creatine phosphate ranged from 3.61 +/- 0.20 in the en docardium to 4.00 +/- 0.20 in the epicardium at 4.7 Tesla. As such, th e canine myocardium exhibits no transmural variation in the T1 values of creatine phosphate. This simple approach can be extended to enable the in vivo measurement of transmural enzymatic rates.