Amide proton transfer image corrected by apparent diffusion coefficient improved diagnostic accuracy in grading brain tumors on a PET/MR system

Amide proton transfer (APT) imaging is useful for grading brain tumors; however, its diagnostic accuracy is compromised by the heterogeneity of the tumor's structure. In this study, we investigated using a PET-magnetic resonance (PET/MR) system whether dividing the APT by the apparent diffusion coefficient (ADC) improves the diagnostic ability of high-grade and low-grade brain tumors by correcting for the effects of tissue structure. The corrected APT (APT/ADC) showed the best diagnostic performance in grading brain tumors compared to APT, ADC, and standardized uptake value (SUV) alone.