¹¹C-Methionine or ¹¹C-Choline PET is superior to MRI in the evaluation of gliomatosis cerebri.

Gliomatosis cerebri (GC) is a rare neuroepithelial tumor which includes 2 types. Type 1: A 12-year-old boy presented with headache and vomiting. MRI showed the diffuse long T2 signal intensity without enhancement in the right hemisphere. ¹¹C-Methionine PET showed local intense tracer accumulation. Type 2: A 59-year-old woman presented with right hemiparesis and headache. MRI revealed diffuse long T2 signal intensity in multiple lobes, and the left occipital lobe yielded heterogeneous enhancement. ¹¹C-Choline PET showed multiple hypermetabolic foci in the same areas. Our findings show that multiple tracer PET might not only reflect the true extent of GC infiltration but also evaluate GC malignant processes more accurately than MRI.