Parallel magnetic resonance imaging

摘要

Parallel MRI started with the introduction of coil arrays in improving radiofrequency (RF) acquisition (what is called ) and continued with an analogous development for RF transmission ( ). Based on differences in the spatial sensitivity distributions of the involved array elements, both techniques try to shorten the respective -space trajectory. Parallel imaging refers to the acquisition of -space data, whereas parallel transmission is dealing with the deposition of RF energy packages in the excitation -space. However, parallel transmission is not simply the reciprocal of parallel imaging. The main goal of parallel imaging is the shortening of the acquisition time. The main goal of parallel transmission is the shortening of the pulse duration of spatially selective RF pulses. The present article describes the basic concept, the state of the art, and the similarities and differences of both technologies.