Figure 4.

MR tracking of ⁽¹²⁵⁾I-fSiO4@SPIO-labeled MSCs in stroked rats after IC and IV injection. T2-weighted MR images of ischemic rat brain before (a,f,k) and after IC (A) and IV (B) transplantation of unlabeled MSCs, ⁽¹²⁵⁾I-fSiO4@SPIO particles, or ⁽¹²⁵⁾I-fSiO4@SPIO-labeled MSCs at day 1 (b,g,l), day 3 (c,h,m), day 7 (d,I,n), and day 14 (e,j,o). Arrows indicated hypointense signals from ⁽¹²⁵⁾I-fSiO4@SPIO particles and ⁽¹²⁵⁾IfSiO4@ SPIO-labeled MSCs after IC injection. For IV injection, no signal from ⁽¹²⁵⁾I- fSiO4@SPIOs or ⁽¹²⁵⁾I-fSiO4@SPIO-labeled MSCs could be detected in the brain.