Echo Planar Imaging скачать в хорошем качестве

Echo Planar Imaging

EPI is the fastest way of imaging in MRI. With echo-planar imaging, a single echo train is used to collect data from all lines of k-space during one TR. This technique shortens the time of acquisition significantly. There are two major types of echo-planar imaging sequences: Spin Echo and Gradient echo sequences. All the lines of k-space can be acquired in a single TR known as single-shot echo-planar imaging or in two or more TRs known as multi-shot echo-planar imaging. The phase-encoding gradient (Gy) and the frequency-encoding (or readout) gradient (Gx) are turned on and off very swiftly. This technique that allows the rapid filling of k-space. So echo-planar imaging can be reflected as a multi echo variant of the GRE sequence same as the fast SE is a multi-echo variant of the SE sequence. We now use Echo-planar imaging for diffusion-weighted imaging instead of SE sequence. Echo-planar imaging is more vulnerable to magnetic susceptibility effects and it provides greater tissue contrast as compare to standard GRE sequences; therefore, echo-planar imaging sequences are used extensively assess cerebral perfusion. Link to my presentation can be found below: https://www.dropbox.com/s/sres30es9i5...