Albert-ludwigs-universitaet Freiburg

Voxalytic Gmbh

Jan Korvink

Andreas Peter

Feng Jia

Peter While

Joerg Funk

Stefan Schonhardt

Nils Spengler

Zhenyu Liu

A passive magnetic flux focusing element having electrically conductive wires () or faces () containing an outer area defined by an outer (), an inner () and connecting edges () forming a closed current loop enclosing a surface area penetrated by a time varying magnetic field flux and through induction sets up a time varying electrical current in the conducting loop thereby achieving a counter magnetic field to the penetrating field completely canceling the penetrating field in the interior of the loop, is characterized in that the element is part of an RF volume- or surface-coil arrangement adapted for receiving and/or transmitting RF signals. Such elements increase the sensitivity and the SNR in MRI and MR spectroscopy experiments due to an increased magnetic flux density by means of Lenz lenses, in combination with a conventional probe.

RF resonator with a Lenz lens

A mufti-channel coil array for use as a transceiver in magnetic resonance imaging (MRI) has a plurality of radio frequency (RF) coils disposed next to one another, devices for electromagnetically decoupling the RF coils and coil elements which are applied onto a planar carrier element (). The carrier elements () have a regular, equilateral polygonal outer contour and the shape of the individual coils () corresponds to the outer contour of the carrier element (). An individual coil () has a loop-shaped structure (), which leads to a decoupling of individual coils () not immediately adjacent to each other when a plurality of individual elements are arranged. The space requirement for adding new coils is reduced, and the modular design makes it possible to easily implement any three-dimensional or two-dimensional shape.

Modular multi-channel coil array for an MRI having decoupling of next but one neighbors

A method for designing an electromagnetic gradient coil for magnetic resonance imaging systems. The method includes the steps of: choosing a set of objectives L, whereby the objectives Lare combined to one weighted-sum objective function; choosing a design variable &#x3c8; for modifying the value of the objectives L; making an initial guess of the value of the design variable &#x3c8;; simulating the magnetic field in a computational domain with respect to the distribution of the surface current density; carrying out a sensitivity analysis by calculating a sensitivity vector G=&#x2202;L/&#x2202;&#x3c8;; updating the design variable &#x3c8;, whereby the value of the design variable &#x3c8; is changed in order to decrease the value of the objective L; determining whether convergency is achieved by either determining whether the value of the objective function does not decrease or the whether the Euclidian norm of the sensitivity vector G approximate to zero; and reconstruction of a discretized coil. The simulation of the magnetic field in a computational domain is effected using a least square finite element analysis. The steps are repeated prior to reconstruction of a discretized coil until convergency is achieved. An effective and improved design for irregular surfaces is thereby created.

MRI gradient coil

Growing community of inventors

Karlsruhe, Germany

Jan Korvink