Susceptibility Contrast in High Field MRI of Human Brain as a Function of Tissue Iron Content

摘要: Magnetic susceptibility provides an important contrast mechanism for MRI. Increasingly, susceptibility-based is being exploited to investigate brain tissue microstructure and detect abnormal levels of iron as these have been implicated in a variety neuro-degenerative diseases. However, it remains unclear what extent magnetic susceptibility-related at high field relates actual concentrations. In this study, we performed weighted imaging function strength on healthy brains vivo post-mortem tissues 1.5 T, 3 T 7 T. Iron histology was the samples comparison. The calculated parameters R(2)(*) signal frequency shift four iron-rich regions (putamen, globus pallidus, caudate, thalamus) showed almost linear dependence (r>or=0.90 R(2)(*); r>or=0.83 phase, p<0.01) strength, suggesting that potential ferritin saturation effects are not relevant susceptibility-weighted strengths up putative (literature-based) concentration 0.048 Hz/T/ppm. histological data from confirmed slope against 0.0099 Hz/T/ppm dry-weight, which equivalent 0.05 wet-weight closely matched value vivo. These results confirm validity using indicator content regions. absence opens way exploit benefits MRI detection distributions with sensitivity resolution.