Amide proton transfer imaging of brain tumors using a self-corrected 3D fast spin-echo dixon method: Comparison With separate B 0 correction

To assess the quantitative performance of three-dimensional (3D) fast spin-echo (FSE) Dixon amide proton transfer (APT) imaging of brain tumors compared with B correction with separate mapping methods. Twenty-two patients with brain tumors (54.2 ± 18.7 years old, 12 males and 10 females) were scanned at 3 Tesla (T). Z-spectra were obtained at seven different frequency offsets at ±3.1 ppm, ± 3.5 ppm, ± 3.9 ppm, and -1560 ppm. The scan was repeated three times at +3.5 ppm with echo shifts for Dixon B mapping. The APT image corrected by a three-point Dixon-type B map from the same scan (3D-Dixon) or a separate B map (2D-separate and 3D-separate), and an uncorrected APT image (3D-uncorrected) were generated. We compared the APT-weighted signals within a tumor obtained with each 3D method with those obtained with 2D-separate as a reference standard. Excellent agreements and correlations with the 2D-separate were obtained by the 3D-Dixon method for both mean (ICC = 0.964, r = 0.93, P