These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Spatial excitation using variable-density spiral trajectories.
    Author: Schröder C, Börnert P, Aldefeld B.
    Journal: J Magn Reson Imaging; 2003 Jul; 18(1):136-41. PubMed ID: 12815650.
    Abstract:
    PURPOSE: To examine the usefulness of variable-density k-space trajectories for the design of multi-dimensional spatially selective RF pulses. MATERIALS AND METHODS: Experimental phantom and in vivo studies were performed and confirmed by simulations. Two-dimensional spatially selective magnetization patterns were excited using variable-density spiral trajectories and analyzed with respect to the signal excitation outside the excitation field of view (FOX). RESULTS: By using variable-density trajectories, signal excitation outside the FOX was drastically reduced compared to trajectories with a uniform density, while maintaining fairly short pulse durations. CONCLUSION: A main advantage of the method is that unwanted signal excitation outside the nominal FOX can be reduced without significantly increasing the duration of the RF excitation pulse. The variable-density approach is useful for all applications that require a well-defined spatial excitation profile, e.g., to perform imaging in a reduced field of view (FOV), for spatial saturation pulses, for curved slice imaging or in MR spectroscopy.
    [Abstract] [Full Text] [Related] [New Search]