In vivo metabolite compartmentalization probed using intracellular GdDTPA

3which translates into an intracellular concentration of 104µ m. Whilst these values are estimates, the similarity suggests that the change in PCr/Cr relaxation is due to intracellular contrast agent and that the MR-visible PCr/Cr signal may predominantly arise from metabolite in the cytosol. Conclusion This study has shown that the in vivo relaxation times of intracellular metabolites may be influenced by the intracellular delivery of GdDTPA 24 hours after electroporation. Despite the significant effects of electroporation on PCr/Cr levels, data from this study suggest that significant components of the MR-visible PCr/Cr resonance reside in the cytosol, supporting current knowledge. Using this approach, the sub-cellular compartmentalization of PCr/Cr and other metabolites in other tissues may be investigated.