Figure 4. An example of discordant ⁶⁸Ga-citrate uptake and MR contrast enhancement.

Post-contrast T1-weighted MR (A) and fused PET/MR (B) images in a 54 year-old female after treatment with bevacizumab for glioblastoma. PET images acquired 138 minutes after injection of 5.6 mCi (207.2 MBq) ⁶⁸Ga-citrate show discordant radiotracer and contrast enhancement in the left medial occipital region. Focal, low-level ⁶⁸Ga-citrate uptake (SUV_max, 0.5) corresponds to an area of faint enhancement (white arrows), while the adjacent area with more intense contrast enhancement is not associated with ⁶⁸Ga-citrate uptake (black arrowheads).