Fig. 4

a Serial slice images of liposomal accumulation taken from 43 to 48 mm (abdomen). The highest signal intensity of the liposomes was at 45–46 mm. Organs are identified: P pancreas tumor, L liver, S spleen, K kidney. b Orthogonal views of the pancreatic tumor and liposomal accumulation through different anatomical planes. c ROI analysis on liposome signal in various locations over time measured in MSOT a.u. Bar height represents the median value and error bars represent the standard deviation throughout the organ. Peak liposomal accumulation occurred at 8 h post-injection. Significantly more liposomes accumulated in the tumor versus off-target organs (p < 0.05). Representative locations of organs can be viewed in Additional file 3: Figure S3