3D-maps of T1 and magnetization transfer (MT) related saturation from MT-FLASH images
Dreha-Kulaczewski S, Kallenberg K, Dechent P, Helms G, Dathe H
Gttingen University, Faculty of Medicine, Gttingen University
Quantitative magnetization transfer (MT) measurements in brain are commonly performed using FLASH with interleaved MT-saturation. By modeling MT by free evolution of the binary spin bath for short TR and small flip-angles, an MT-related saturation term is identified in the signal equation. Thus, maps of T1, PD-signal, and percentage MT-saturation can be calculated from an MT and two reference 3D-scans (1.25 mm resolution; acquired in 13 min on a 3 Tesla MR-system). The MT-saturation is proportional to the macromolecular fraction and increases with TR. The MT-saturation shows a high contrast between white matter and cortex and multiple sclerosis lesions.