Fig. 4.

Patient 4. a T2-weighted FLAIR MRI shows a left frontal hyperintense tumor with minimal contrast enhancement on T1-weighted images (not shown). b MET PET shows a large hotspot region in the tumor. c DSC perfusion MRI with rCBV greyscale map shows areas with low, normal, and high perfusion in the region corresponding to the PET hotspot. d Co-registration of MRI, PET, and corresponding histological images with defined ROIs (ROI₁, red and orange; ROI₂ yellow). There was no identifiable ROI₃ in this sequence. As shown, ROI₁ covers almost the entire tumor volume