A.A. Hurshkainen1, I.J. Voogt2, A.A. Haghnejad2, D.W. Klomp2, P.R. Luijten2, I.V. Melchakova1, S.B. Glybovski1, C.A.T. van den Berg2, and A.J.E. Raaijmakers2
1Department of Nanophotonics and Metamaterials, ITMO University, Saint-Petersburg, Russian Federation, 2Imaging Division, UMC Utrecht, Utrecht, Netherlands
Dipole antennas are being used increasingly for body
imaging at 7T. For dipole antennas, SAR levels can be reduced by increasing the
antenna-subject spacing. However, this will increase inter-element
coupling. In this study we investigate
the relationship between antenna-subject spacing, inter-element coupling and maximum
local SAR levels for fractionated dipole antennas. We demonstrate that the
originally presented antenna-subject spacing (2 cm) can be increased without
significant scattering losses. We have realized an 8-element array of
fractionated dipole antennas with 4 cm antenna-subject spacing and demonstrate uncompromised
imaging performance with 45% lower local SAR levels in comparison to the
original design.
