Download or read book Design and Implementation of Pulse Sequences for Application in MRI written by Geon-Ho Jang and published by . This book was released on 1999 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two different groups of pulse sequences were designed and implemented on a clinical magnetic resonance imaging system. Both sets of sequences were used to generate images of phantoms and/or human brains. The first group of sequences were those which compensate for the effects of flow using the gradient moment nulling technique. Both gradient echo and spin echo sequences with first, second, and third order motion compensation were implemented. The sequences were optimized to take full advantage of the capabilities of the gradient hardware. The spin echo sequences also incorporated a number of techniques for suppression of unwanted echoes that often result in ghost images. A technique is introduced for flow compensation with minimum echo of time and with suppressing unwanted echoes in spin echo sequence. The developed sequences were found to have shorter echo times and better motion compensation than comparable sequences designed by without motion compensation or provided by the instrument manufacturer. The second group of sequences was designed for mapping the diffusion tensor using the pulsed-gradient spin echo (PGSE) technique. A multiple echo PGSE technique was developed in order to minimize the total acquisition time needed to map the full tensor. The sequence is applied with multi slice mode. All components of diffusion tensor measure a single shot experiment. The sequence is applied in diffusive phantoms. The resulting sequences were found to have some utility but need further refinement.