English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Analysis of RF transmit performance for a 7T dual row multichannel MRI loop array

Kozlov, M., & Turner, R. (2011). Analysis of RF transmit performance for a 7T dual row multichannel MRI loop array. In 33rd Annual International Conference of the IEEE EMBS.

Item is

Files

show Files

Locators

show

Creators

show
hide
 Creators:
Kozlov, Mikhail1, Author              
Turner, Robert1, Author              
Affiliations:
1Department Neurophysics, MPI for Human Cognitive and Brain Sciences, Max Planck Society, ou_634550              

Content

show
hide
Free keywords: Antenna arrays, Biomedical imaging, Computational electromagnetics
 Abstract: We present a numerical investigation of the RF fields generated inside a human head by single and dual-row loop arrays. For a uniform circular polarization (CP) mode excitation, a dual-row array has no advantage for human brain excitation. Significant improvement of B1+ homogeneity with a simultaneous increase of coverage in the axial direction can be obtained by using a dual-row array together with a static RF shim: that is, excitation of both rows separately in CP mode, while providing the upper row elements with a +90 phase shift relative to axially adjacent lower row elements. For this case the excitation efficiency over the entire brain remains practically unaffected, and the improved B1+ coverage results in a relatively smaller amount of power delivered to brain. To keep the mean B1+ across the brain equal to its value in a uniform CP excitation mode, a larger transmit power level is required. This results in a moderate increase of peak SAR10g. The location of peak SAR10g moves from the brain (uniform CP mode location) to the nose skin. The performance of dual-row arrays in transmit SENSE operation will be explored in future investigations.

Details

show
hide
Language(s):
 Dates: 2011
 Publication Status: Published in print
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: -
 Identifiers: -
 Degree: -

Event

show
hide
Title: 33rd Annual International Conference of the IEEE EMBS
Place of Event: Boston, MA, USA
Start-/End Date: 2011-08-30 - 2011-09-03

Legal Case

show

Project information

show

Source 1

show
hide
Title: 33rd Annual International Conference of the IEEE EMBS
Source Genre: Proceedings
 Creator(s):
Affiliations:
Publ. Info: -
Pages: - Volume / Issue: - Sequence Number: - Start / End Page: - Identifier: -