Abstract
Although it has been 40 years since MRI equipped with gradient coil was developed by Dr. Lauterbur in 1973, MRI technology is still under development for both hardware and imaging methods, and has been commercially available. This article introduces two current technologies, parallel transmission available on Siemens MRI and multi-band EPI under development. Parallel transmission can reduce transmission field inhomogeneity, which is caused by penetration depth of high frequency Radio frequency, typically on 3T MRI. Moreover, parallel transmission enables the local excitation along with read-out and phase-encoding direction, in addition to the excitation along with slice direction in the conventional method. Multi-band EPI, one of outcomes of Human Connectome Project in the USA, can be widely applied to fMRI (functional MRI), Diffusion Tensor Imaging (DWI) and Diffusion Spectrum Imaging (DSI), offering high-temporal and spatial resolution, reduction of data acquisition time, and improvement of statistical power.
