A Parametric Study of Radiative Dipole Body Array Coil for 7 Tesla MRI

TL;DR

This paper investigates how the placement of radiative dipole antennas in a phased array affects MRI performance at 7 Tesla, using numerical simulations and in-vivo experiments to optimize array design.

Contribution

It provides a comprehensive parametric analysis of dipole positioning effects on array efficiency and safety metrics for ultrahigh-field MRI.

Findings

Optimal dipole placement improves $B_1^{+}$ efficiency.

Mutual coupling is minimized with specific array configurations.

Experimental results validate numerical predictions.

Abstract

In this contribution we present numerical and experimental results of a parametric quantitative study of radiative dipole antennas in a phased array configuration for efficient body magnetic resonance imaging at 7T via parallel transmission. For magnetic resonance imaging (MRI) at ultrahigh fields (7T and higher) dipole antennas are commonly used in phased arrays, particularly for body imaging targets. This study reveals the effects of dipole positioning in the array (elevation of dipoles above the subject and inter-dipole spacing) on their mutual coupling, $B_1^{+}$ per $P_{acc}$ and $B_1^{+}$ per maximum local SAR efficiencies as well as the RF-shimming capability. The numerical and experimental results are obtained and compared for a homogeneous phantom as well as for a real human models confirmed by in-vivo experiments.