Introducing MRI: Fast Gradient Echo and Echoplanar Imaging (38 of 56)

I'm so glad the last part about t2* was clarified. And I wish I can enroll in an mri class from Nigeria. There's so much wealth of knowledge I just want to tap into.

First, fantastic series and great explanations. Two questions: 1. For the fast gradient echo sequence, is signal acquired during the first gradient echo? Or is there a first 'dummy' gradient that dephases the spins so that an increasing signal is acquired during the next gradient? Technically, as it is explained here, the first acquired signal is decreasing during acquisition. 2. Am I understanding this correctly that in this EPI sequence, an entire 256 by 256 image is acquired in 1 - 2 ms? So that means that in every 2/256 ms, 256 data points are collected? That is quite incredible.

very nice explanation for clearing all the concepts about the echoplanar imaging......but during the spinecho echoplanar imaging explanation in the later of this lecture there was no mention about the 180 degree pulse which we shoud give after every acquision of the echo that is neccessary, because without the 180 flip the image will be only the T2* weighted and there will be no difference between the T2 and gre image???? that is the 180 degree pulse should be given before every time we image.

"There is no TR" 🤯