Moving-coil loudspeakers generally provide a substantial improvement in linearity when current driven, together with the elimination of voice-coil heating effects. Consequently there is a need to investigate low-distortion power amplifier topologies suitable for this purpose. After considering established current feedback approaches, a novel method using a common-base isolation stage is outline...

Outcome. This live show has the ambitious goal of showing to people who are not expert in RF engineering/electronics the fundamental steps to be followed for a coil construction. The steps can be summarized as follows: 1) Choice of the coil design according to the available MR system and the anatomical region 2) Choice of the material 3) Coil construction a. Tuning b. Matching c. Decoupling We ...

Circular loops are the most common MR detectors. Loop arrays offer improved signal-to-noise ratios (SNRs) and spatial resolution, and enable parallel imaging. As loop size decreases, loop noise increases relative to sample noise, ultimately dominating the SNR. Here, relative noise contributions from the sample and the coil are quantified by a coil noise figure (NF), NF(coil), which adds to the ...

Radio Frequency coil development, one component of a functioning magnetic resonance imaging (MRI) system, has evolved since the beginning of MRI into a very diverse area. Today for example, transmit and receive coils, volume and surface coils, and single channel and multiple channel coils are all included. Coils are created to fit the particular needs of specific research purposes, taking into ...

This paper reports on a micro saddle coil for local high-resolution magnetic resonance imaging (MRI) fabricated by embedding a flexible coil pattern into a polydimethyilsiloxane (PDMS) tube. We can change the sensitivity of the micro coil by deforming the shape of the coil from a saddle-shaped mode to a planar-shaped mode. The inductance, the resistance, and the Q-factor of the coil in the sadd...

The effect of geometrical asymmetry β (described by the length-diameter ratio of rods) on the rod-coil diblock copolymer phase behavior is studied by implementation of self-consistent field theory (SCFT) in three-dimensional (3D) position space while considering the rod orientation on the spherical surface. The phase diagrams at different geometrical asymmetry show that the aspect ratio of rods...

Introduction: A new concept relating to a fast mechanically rotating radio-frequency (RRF) transceive coil and method for application in MRI is presented. The introduction of controlled RF system rotation as additional degree of freedom during imaging facilitates the use of (at least) one coil sensitivity pattern to effectively emulate a conventional RF coil array over time. This approach aims ...

OBJECTIVE To evaluate the clinical application of phased-array surface coil intensity correction in magnetic resonance imaging (MRI) in spinal metastases. METHODS 3 phantoms and 50 patients with a corresponding total number of 80 spinal metastases were included in this study. Fast spin echo T1- and T2- weighted MRI with and without surface coil intensity correction was routinely performed for...

Purpose: Most published studies of multi-channel transmit coils report only the radiation losses, single element reflection (Sxx) and power absorbed by phantoms or human body models. However, at higher frequency the power reflected by the entire coil (Pref_coil) as well as the surface and volume losses in coil elements become important for understanding the coil performance. Our goal was to inv...