Origin of B0 orientation dependent R2(*) (=1/T2(*)) in white matter.

ABSTRACT: Recent MRI studies have demonstrated that the relative orientation of white matter fibers to the B0 field significantly affects R2(*) measurement. In this work, the origin of this effect was investigated by measuring R2 and R2(*) in multiple orientations and fitting the results to magnetic susceptibility-based models and magic angle-based models. To further explore the source of magnetic susceptibility effect, the contribution of tissue iron to the orientation dependent R2(*) contrast was investigated. Additionally, the effects of temperature on R2(*) and orientation dependent R2(*) contrasts were studied to understand the differences reported between a fixed specimen at room temperature and in vivo at body temperature. The results suggest that the B0 dependent R2(*) variation is better ex

SUBMITTER: Oh SH 

PROVIDER: S-EPMC3638902 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature