Eth Zurich

Unversität Zürich

Universitaet Zuerich

Eidgenossische Technische Hochschule (eth)

Eidgenossische Technische Hochschule Zurich

Simon Gross

Christoph Barmet

Klaas P Pruessmann

Marcel Eric Delavy

David Brunner

Linda Schnorf

Jonas Schmid

A magnetic resonance (MR) apparatus comprises magnet means for generating a main magnetic field in a sample region, encoding means for generating encoding magnetic fields superimposed to the main magnetic field, RF transmitter means for generating MR radiofrequency fields, driver means for operating said encoding means and RF transmitter means to generate superimposed time dependent encoding fields and radiofrequency fields according to an MR sequence for forming images or spectra; and acquisition means for acquiring an MR signal from said object. The magnet means comprise a primary magnetic field source providing a static magnetic field Band at least one secondary magnetic field source providing an adjustable magnetic field B'. To provide improved shimming, the secondary magnetic field source comprises at least two spatially distinct portions of a first magnetic material and of a second magnetic material, respectively, said first magnetic material having a first magnetic moment density m1 and said second magnetic material having a second magnetic moment density m2, and means for independently adjusting said second magnetic moment density m2 by variation of an external control parameter.

Bshimming device for MRI

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

Growing community of inventors

Zurich, Switzerland

Simon Gross