Phase map based investigation of intravoxel signal dephasing in gradient echo MRI
Rauscher A, Reichenbach J, Witoszynskyj S, Barth M, Sedlacik J
IDIR, FSU, Core Unit MR Methods
Macroscopic inhomogeneities of the static magnetic field cause anaccelerated T2` decay due to intravoxel spin dephasing. In lowresolution gradient echo images this leads to a poor signal-to-noiseratio in magnetic inhomogeneous regions. We present a method based onunwrapped single-echo, high resolution phase images that allows tosimulate and investigate intravoxel signal dephasing and BOLDsensitivity in a systematic manner. The method can be used todetermine optimum scan parameters (in-plane resolution, echo time,slice thickness, obliqueness of the imaging plane, z-shimming) on anindividual basis.