Figure 4.

Fluorescent contrast agent uptake and contrast evaluation in whole brains with U251 tumors. (A-D) shows mean fluorescence intensity values of normal brain (N) and tumor tissues (T) for each fluorescent contrast agent presented as a box and whisker plot for (A) TMR-PEG1k, (B) TMR-PEG550, (C) IRDye800CW and (D) ICG. Each dot represents the mean intensity for an individual animal and the blue line indicates the value for a naïve brain from that fluorescence imaging channel. (E) Tumor-to-background ratio (TBR) for all contrast agents, including CE-MRI, at each timepoint represented as the median and interquartile range between animals (IQR). (F) Contrast-to-noise ratio (CNR) for all contrast agents at each timepoint represented as a median and IQR. The grey dotted line starting at 3 min and extending across the plot of (E) and (F) represents the median TBR and CNR for the Early CE-MRI acquisition.