Amide Proton Transfer Imaging for High-Grade and Low-Grade Brain Tumors

Masahiro Ida¹, Toshiki Wakayama, Katsutoshi Murata²

We evaluate whether amide proton transfer (APT) imaging can provide additional information in differentiating malignant brain tumors (WHO grade III & IV) from benign tumors (grade II) and chemotherapy-induced pseudoprogression and irradiation necrosis. APT imaging was performed at 3-tesla using a gradient-echo sequence for CEST (W.I.P) with thirteen frequency offsets (4.5ppm). Increased APT signal was observed in tumor tissues in grade III and IV. However, no elevation of APT signal was recognized in grade II tumors, chemoradiation-indueced pseudoprogression and necrosis. APT imaging can provide adjunct information utilized for differentiating malignant brain tumors from benign tumors and post-therapeutic necrosis.