Figure 1. In vivo imaging patterns of ¹⁹F and SPIO-enhanced MRI in the acute stage of cerebral photothrombosis.

(A) All images were acquired 24 hours after PT induction. The ¹H/¹⁹F overlay shows fluorine signal within the entire cortical infarction when PFC were applied directly after the end of illumination (left, upper image). Delayed injection two hours later led to a rim-like signal in the boundary zone (left, lower image). Note the similar distribution pattern of signal loss on T2-w MRI when SPIO were administered immediately after illumination (right, upper image) and with two hours delay (right, lower image). The relative volume of iron-induced signal loss and ¹⁹F signal in proportion to the total infarct volume decreased from 0.85±0.13/0.61±0.13 to 0.59±0.03/0.29±0.08 (PFC/SPIO) within the first two hours after illumination (B) (both cases p<0.05). When corresponding time points of SPIO/¹⁹F marker injection were compared a significant difference was found between the volume fraction showing ¹⁹F signal and the signal voids in SPIO-enhanced MRI (p<0.05).