Due to the non-renewable nature of hyperpolarized signal, the effects of non-ideal slice excitation can significantly impact signal evolution. These effects could be compounded by cross-talk between adjacent slices when contiguous multi-slice evolution. To correct for these effects, the expected multi-slice profile is used to decompose the measured hyperpolarized signal durring pharmacokinetic analysis. This methos was compared via simulation agains conventional fitting where each slice is assumed to have an ideal profile with the prescribed excitation angle. The multi-slice decomposition method reduced error in the apparent rate constant for conversion of hyperpolarized pyruvate into lactate.