#Spin echo sequence diagram series#
#Spin echo sequence diagram download#

It is an important step forward in the development of bringing myelin water imaging to the mainstream.

#Spin echo sequence diagram download#

GS, GP, and GF are the slice selective, phase-encoding, and frequency-encoding gradients, respectively. Download scientific diagram Spin-echo sequence from publication: Miniaturised NMR sensor Realisation of a miniaturised NMR sensor Miniaturization and Sensors ResearchGate, the professional. Ray Ballinger Diagnosis not applicable In the first figure, RF is the radiofrequency pulse, a slice selective 90-degree pulse followed by two 180-degree refocusing pulses. Together, these two studies provide strong evidence of the reproducibility of myelin water imaging. Spin echo sequence diagrams Case contributed by Dr J. All spin echo sequences include a slice selective 90-degree pulse followed by one or more 180 degree refocusing pulses as shown in the diagrams. Results from the two scanners were found to be highly correlated but with a significant offset in myelin water fraction of 4.3%. The two variables of interest in spin echo sequences are the repetition time (TR) and the echo time (TE). In this sequence, several 180 refocusing radio-frequency pulses are delivered during each echo time (TR) interval, and the phase-encoding gradient is briefly switched on between echoes. A multicenter reproducibility study of myelin water imaging in brain between two scan vendors (Siemens and Philips) was also performed. Fast spin echo (FAISE or FSE, ref 65bis), also called turbo spin echo (TSE) is an MRI sequence that results in fast scan times. The reproducibility of myelin water imaging in the spinal cord was found to be high (coefficient of variation = 6.1%, Cronbach’s α = 0.89). In this study I present the first implementation of myelin water imaging using GRASE in human cervical spinal cord. Proton density or T2-weighted spin echo sequences are particularly slow. The GRASE sequence has so far only been applied to brain imaging, and reproducibility between different scan vendors has not been assessed. The diagrams shown are based on those in current use on a clinical scanner. In 2007, a paradigm shift took place when the standard sequence for myelin water imaging changed from a multi-echo spin echo sequence to a gradient and spin echo (GRASE) sequence.

Examine the effect of inversion-recovery on contrast and its applications. Explain the contrast obtained, the advantages and disadvantages of each sequence. With each repetition, a k-space line is filled, thanks to a different phase encoding.

#Spin echo sequence diagram series#

This series is repeated at each time interval TR (Repetition time). Describe the principles of signal acquisition for each type of sequence. Generic diagram The spin echo sequence is made up of a series of events : 90 pulse 180 rephasing pulse at TE/2 signal reading at TE. Myelin water imaging is a quantitative magnetic resonance imaging technique that can be used as an in vivo biomarker for myelin in the central nervous system. To present the members of the spin echo and gradient echo sequence families. If we take a close look at a pulse sequence diagram, we can see that during the excitation pulse, we need to create resonance that affects only a slice of data.