English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  OTUP-workflow: Target specific optimization of the transmit k-space trajectory for flexible universal parallel transmit RF pulse design

Geldschläger, O., Bosch, D., & Henning, A. (2022). OTUP-workflow: Target specific optimization of the transmit k-space trajectory for flexible universal parallel transmit RF pulse design. NMR in Biomedicine, Epub ahead. doi:10.1002/nbm.4728.

Item is

Basic

show hide
Genre: Journal Article

Files

show Files

Creators

show
hide
 Creators:
Geldschläger, O1, 2, Author              
Bosch, D2, 3, Author              
Henning, A1, 2, Author              
Affiliations:
1Research Group MR Spectroscopy and Ultra-High Field Methodology, Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_2528692              
2Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_1497794              
3Department High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_1497796              

Content

show
hide
Free keywords: -
 Abstract: Purpose: To optimize transmit k-space trajectories for a wide range of excitation targets and to design 'Universal pTx RF pulses' based on these trajectories. Methods: Transmit k-space trajectories (stack-of-spirals and SPINS) were optimized to best match different excitation targets using the parameters of the analytical equations of spirals and SPINS. The performances of RF pulses designed based on optimized and non-optimized trajectories were compared. The optimized trajectories were utilized for universal pulse design. The universal pulse performances were compared with subject specific tailored pulse performances. The OTUP-workflow (Optimization of transmit k-space Trajectories and Universal Pulse calculation) was tested on three test target excitation patterns. For one target (local excitation of a central area in the human brain) the pulses were tested in vivo at 9.4T. Results: The workflow produced appropriate transmit k-space trajectories for each test target. Utilization of an optimized trajectory was crucial for the pulse performance. Using unsuited trajectories diminished the performance. It was possible to create target specific universal pulses. However, not every test target is equally well suited for universal pulse design. There was no significant difference in the in vivo performance between subject specific tailored pulses and universal pulse at 9.4T. Conclusions: The proposed workflow further exploited and improved the universal pulse concept by combining it with gradient trajectory optimization for stack-of-spirals and SPINS. It emphasized the importance of a well-suited trajectory for pTx RF pulse design. Universal and tailored pulses performed with a sufficient degree of similarity in simulations and a high degree of similarity in vivo. The implemented OTUP-workflow and the B0 /B1 + map data from 18 subjects measured at 9.4T are available as open source (https://github.com/ole1965/workflow_OTUP.git).

Details

show
hide
Language(s):
 Dates: 2022-03
 Publication Status: Published online
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: -
 Identifiers: DOI: 10.1002/nbm.4728
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: NMR in Biomedicine
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: London : Heyden & Son
Pages: - Volume / Issue: Epub ahead Sequence Number: - Start / End Page: - Identifier: ISSN: 0952-3480
CoNE: https://pure.mpg.de/cone/journals/resource/954925574973