A: (left): 0.5 mM MnCl2 was sufficient to increase the T1 signal of pre-labeled healthy hAMSCs, but injured/dead DOX hAMSCs failed to take up MnCl2; (right) BLI shows better survival of hAMSCs 48 hrs after incubation with either 0.1 mM or 0.5 mM MnCl2, compared to DOX hAMSCs. 1B: (left) Hindlimb MRI showing positive MEMRI signal from pre-labeled hAMSCs in left hindlimb; (right) corresponding positive BLI signal from same hindlimb, confirming live hAMSCs. 1C: (top) short- (SAX) and long- (LAX) axis MEMRI of mouse heart immediately post-hAMSC delivery. Note the positive signal in the basal inferior wall (arrow) whereas simultaneous DOX hAMSC injection in anterior wall shows no MEMRI signal (dotted arrow); (bottom) 2 days after hAMSC delivery, i.p. MEMRI injection reveals intense uptake in basal inferior wall (healthy hAMSCs, arrow) with no uptake in anterior wall (DOX hAMSCs, dotted arrow).