Unversität Zürich

Eidgenossische Technische Hochschule (eth)

Eidgenossische Technische Hochschule (eth) Eth Zentrum

Eidgenössische Technische Hochschule (eth) and Universität Zürich

Eidgenossiche Technische Hochschule (e T H)

Eidgenossische Technische Hochschule Zurich

Christoph Barmet

Klaas Prussmann

David Brunner

Bertram Wilm

Simon Gross

Peter Boesiger

Nicola De Zanche

Marcel Eric Delavy

Klass Prüssmann

Sebastian Kozerke

Kai Eberhardt

Jonas Schmid

Linda Schnorf

Michael Schär

Maximilian Häberlin

Klaas PRÜSSMANN

Thomas Schmid

Klaas P PRÜSSMANN

David O Brunner

Maximilian HÄBERLIN

Measuring instrument for measuring magnetic fields

A magnetic field probe, particularly for magnetic resonance applications, comprises: &#x2014;a detector liquid that exhibits a nuclear magnetic resonance (NMR) line characterized by a chemical shift &#x3b4;; &#x2014;an electrically conductive structure surrounding the detector liquid for receiving therefrom a magnetic resonance signal; and &#x2014;a container containing the detector liquid; &#x2014;the detector liquid containing paramagnetic dopant means dissolved therein; &#x2014;said NMR transition having an observable resonance frequency &#x3c9; when the field probe is placed in an external magnetic field; and has orientation means for orienting the field probe in relation to a reference direction of said external magnetic field. The concentration cof said paramagnetic dopant means is selected in such manner that, when the field probe is placed into an external magnetic field Band oriented in a predefined manner with respect to said external magnetic field at a given temperature T, a temperature dependence &#x3c9;'(T) of said resonance frequency is substantially zero.

Temperature compensated NMR magnetic field probes

A method of determining an actual gradient impulse response function during execution of a magnetic resonance (MR) imaging or spectroscopy sequence, wherein a main magnetic field is generated in a sample region of an MR apparatus by means of a main magnet and wherein superimposed time dependent gradient fields and radiofrequency fields in a first RF band are generated in the sample region according to a first MR sequence for forming images or spectra, the gradient fields being generated by gradient forming means of the MR apparatus operated according to a gradient forming sequence part of said first MR sequence, the MR apparatus further comprising at least one magnetic field probe. The method comprises the steps of: &#x2014;operating said at least one magnetic field probe according to a second sequence, whereby a time dependent probe signal is repeatedly acquired from each magnetic field probe during a probe acquisition time window, thus providing at least one time dependent probe signal; &#x2014;obtaining said actual gradient impulse response function by calculating an impulse response function from said at least one time dependent probe signal and from said gradient forming sequence part.

Method of determining a gradient impulse response function during execution of a magnetic resonance imaging or spectroscopy sequence

A method of determining the position of at least one magnetic field probe located within a pre-defined volume of interest within a magnetic resonance (MR) imaging or spectroscopy arrangement comprises applying a spatially and temporally variable magnetic reference field having a unique time-course at every point in said volume of interest during a preselected time window. An MR signal is ac-quired from said magnetic field probe during said time window, and the position of the probe is determined from the probe MR signal.

Determining positions of a magnetic field probe in a magnetic resonance measurement

A dynamic field camera arrangement for monitoring electromagnetic field behavior in a spatial region comprises a main magnetic field and a radiofrequency (RF) field limited to a first RF band, particularly in an MRI or NMR apparatus. The arrangement comprises a magnetic field detector set comprising a plurality of low-frequency magnetic field detectors, each one of said magnetic field detectors comprising a magnetic resonance (MR) active substance, means for pulsed MR excitation of said substance and means for receiving an MR signal generated by said substance, wherein said pulsed excitation and said MR detector signal is in a second RF band that does not overlap said first RF band. The MR signal receiving means comprise a first RF filter which suppresses RF signal from said first RF band and transmits RF signal from said second RF band.

Dynamic field camera arrangement for magnetic resonance applications and methods for operating the same

A method of observing axial magnetization (Mz) in an object (O) located in a main magnetic field (B) comprises the step of determining magnetic field intensity (B) in at least one magnetic field probe (P) arranged in the neighborhood of the object. The magnetic field probe comprises a magnetic resonance (MR) active substance, means for pulsed MR excitation of the substance and means for receiving an MR signal generated by said substance.

Observation of axial magnetization of an object in a magnetic field

A magnetic field probe comprises a sample that exhibits magnetic resonance at an operating frequency, an electrically conductive structure surrounding the sample for receiving a magnetic resonance signal therefrom, and a solid jacket encasing the sample and the conductive structure. The jacket is made of a hardened two-component epoxy system containing a paramagnetic dopant dissolved therein, with the concentration of the dopant being chosen such that the jacket has a magnetic susceptibility that is substantially identical to the magnetic susceptibility of the conductive structure.

Magnetic field probe and method for manufacturing the same

The present invention describes a magnetic resonance imaging method wherein spatially resolved frequency sensitive image data are collected by means of free precession sequences employing very small radio frequency (RF) excitation pulses per unit time which result in highly frequency selective steady-state signals dominated by linear properties of the system, for which the superposition principle holds. By appropriate linear combination of steady state signals of N different frequencies, N resonance lines can be acquired simultaneously. This method allows spectroscopic recordings with very low RF power deposition which renders the method suitable for applications at high static magnetic field strengths.

Measuring method of spatially resolved frequency selective images

Growing community of inventors

Zurich, Switzerland

Christoph Barmet