Snapshot MRI with T2*‐weighted magnetization preparation

Abstract

A method for encoding T₂*-dependent contrasts into the preparation period of magnetization-prepared uitrafast MRI sequences is demonstrated and validated. The preparation block consists of a 90°—T—90°_p sequence, where p is shifted by 90° for successive images. By adding two such successive images in quadrature, a combined image is obtained, in which the pixel intensities depend on the incoherent intravoxel dephasing that occurred during T in a way that is similar to the dependence on TE in a gradient-echo sequence. The method could therefore be useful for applications that require very short repetition times for good temporal resolution, together with detection of T₂*-weighted contrasts, such as functional MRI in the brain.