Abrégé

The invention relates to a magnetic resonance imaging system comprising at least one radiofrequency gradiometer (GR), which comprises two conductive coils (BCA, BCB), referred to as capture coils, having a common sensitivity axis (z) and spaced apart along the axis, wherein each of the coils is connected in series to another conductive coil (BEA, BEB), referred to as the input coil, to form a flux concentrator (CF), and wherein each input coil is inductively coupled to a SQUID magnetometer (MSA, MSB); characterised in that the gradiometer also comprises an electronic processing circuit (CET) configured to linearly combine output signals (VSA, VSB) from the SQUID magnetometers in order to obtain a signal (VS) representative of a difference between radiofrequency magnetic field values (Bz) corresponding to the two capture coils.

Classes IPC  ?

• G01R 33/32 - Systèmes d'excitation ou de détection, p. ex. utilisant des signaux radiofréquence

Abrégé

The invention relates to a magnetic resonance imaging (MRI) device (1), designed to image an essentially metallic component, comprising means (b'') for generating a polarization magnetic field intended to be applied to said component (a), radiofrequency (RF) means (g) for exciting said component (a), detection means cooperating with antenna means, for delivering a magnetic resonance imaging (MRI) signal, and means for processing said MRI signal so as to deliver characteristic information about the state of said component (a). The component (a) is subjected to a very weak field of less than 10 mT, and the detection means comprise a pick-up coil (h) magnetically coupled with the polarization means (b'') and the radiofrequency means (g) and operating as a flux concentrator, and a SQUID (superconducting quantum interference device) detector arranged downstream of said pick-up coil (h) via a transformer.

Classes IPC  ?

• G01R 33/32 - Systèmes d'excitation ou de détection, p. ex. utilisant des signaux radiofréquence
• G01R 33/36 - Détails électriques, p. ex. adaptations ou couplage de la bobine au récepteur
• G01R 33/44 - Dispositions ou appareils pour la mesure des grandeurs magnétiques faisant intervenir la résonance magnétique utilisant la résonance magnétique nucléaire [RMN]
• G01R 33/565 - Correction de distorsions d'image, p. ex. dues à des inhomogénéités de champ magnétique
• G01N 24/08 - Recherche ou analyse des matériaux par l'utilisation de la résonance magnétique nucléaire, de la résonance paramagnétique électronique ou d'autres effets de spin en utilisant la résonance magnétique nucléaire

Classes IPC  ?

• G01N 24/08 - Recherche ou analyse des matériaux par l'utilisation de la résonance magnétique nucléaire, de la résonance paramagnétique électronique ou d'autres effets de spin en utilisant la résonance magnétique nucléaire
• G01R 33/32 - Systèmes d'excitation ou de détection, p. ex. utilisant des signaux radiofréquence
• G01R 33/36 - Détails électriques, p. ex. adaptations ou couplage de la bobine au récepteur
• G01R 33/44 - Dispositions ou appareils pour la mesure des grandeurs magnétiques faisant intervenir la résonance magnétique utilisant la résonance magnétique nucléaire [RMN]
• G01R 33/565 - Correction de distorsions d'image, p. ex. dues à des inhomogénéités de champ magnétique

Abrégé

A radiofrequency detection and acquisition system, which is based on SQUID and configured to be integrated into a nuclear magnetic resonance system, comprises a primary detection antenna, a flux transformer having an inlet winding connected to the primary detection antenna, a low critical temperature SQUID device for capturing the magnetic flux produced by an outlet winding of the flux transformer and supplying a secondary detection signal, a cryogenic device for cooling the SQUID device and the flux transformer, and means for processing the secondary detection signal emitted by the SQUID device to supply an analogue acquisition signal. The primary detection antenna may be of the volume type, comprising Helmholtz coils or saddle coils, or a more complex volume geometry, particularly gradiometric geometry. The means for processing the secondary detection signal may comprise a flux-locked loop, provided to linearize the response of the SQUID device.

Classes IPC  ?

• G01R 33/32 - Systèmes d'excitation ou de détection, p. ex. utilisant des signaux radiofréquence
• A61B 5/05 - Détection, mesure ou enregistrement pour établir un diagnostic au moyen de courants électriques ou de champs magnétiquesMesure utilisant des micro-ondes ou des ondes radio
• A61B 5/245 - Détection de champs biomagnétiques, p. ex. de champs magnétiques produits par des courants bioélectriques spécialement adaptée aux signaux magnétoencéphalographiques [MEG]
• G01R 33/34 - Détails de structure, p. ex. résonateurs
• G01V 3/12 - Prospection ou détection électrique ou magnétiqueMesure des caractéristiques du champ magnétique de la terre, p. ex. de la déclinaison ou de la déviation fonctionnant par ondes électromagnétiques

Abrégé

The invention relates to a flux concentrator device (5) arranged upstream of an ultrasensitive magnetometer (3), which device is intended to input an external magnetic flux and deliver a concentrated flux at the input of the magnetometer (3) and is characterised in that it comprises a primary gradiometric volumetric magnetic detection antenna (50) cooled to a cryogenic temperature and a flux transformer (55) arranged between the primary detection antenna (50) and the magnetometer (3), this flux transformer (55) having a primary winding (6) connected to the primary detection antenna (50).

Classes IPC  ?

• G01R 33/24 - Dispositions ou appareils pour la mesure des grandeurs magnétiques faisant intervenir la résonance magnétique pour la mesure de la direction ou de l'intensité de champs magnétiques ou de flux magnétiques
• G01R 33/34 - Détails de structure, p. ex. résonateurs
• G01R 33/32 - Systèmes d'excitation ou de détection, p. ex. utilisant des signaux radiofréquence
• G01R 33/565 - Correction de distorsions d'image, p. ex. dues à des inhomogénéités de champ magnétique

Abrégé

Radiofrequency (RF) detection and acquisition system (1) which is based on SQUID and which is provided particularly to be integrated into a nuclear magnetic resonance (IRM or RMN) equipment item, comprising a primary detection antenna (5), a flux transformer (2) having an inlet winding (6) which is connected to the primary detection antenna (5), a low critical temperature SQUID device (3) which is provided to capture the magnetic flux produced by an outlet winding (8) of the flux transformer (2) and to supply a secondary detection signal, a cryogenic device provided to cool the SQUID device (3) and the flux transformer (2), and a step (4) of processing the secondary detection signal emitted by the SQUID device (3) in order to supply an analogue acquisition signal. The primary detection antenna (5) is of the volume type, comprising Helmholtz coils or saddle coils, or a more complex volume geometry, particularly gradiometric geometry, and the step (4) of processing the secondary detection signal comprises a flux-locked loop (FLL) which is provided to linearise the response of the SQUID device (3).

Classes IPC  ?

• G01R 33/32 - Systèmes d'excitation ou de détection, p. ex. utilisant des signaux radiofréquence
• G01R 33/34 - Détails de structure, p. ex. résonateurs
• G01R 33/44 - Dispositions ou appareils pour la mesure des grandeurs magnétiques faisant intervenir la résonance magnétique utilisant la résonance magnétique nucléaire [RMN]

Abrégé

Radiofrequency (RF) detection and acquisition system (1) which is based on SQUID and which is provided particularly to be integrated into a nuclear magnetic resonance (IRM or RMN) equipment item, comprising a primary detection antenna (5), a flux transformer (2) having an inlet winding (6) which is connected to the primary detection antenna (5), a low critical temperature SQUID device (3) which is provided to capture the magnetic flux produced by an outlet winding (8) of the flux transformer (2) and to supply a secondary detection signal, a cryogenic device provided to cool the SQUID device (3) and the flux transformer (2), and a step (4) of processing the secondary detection signal emitted by the SQUID device (3) in order to supply an analogue acquisition signal. The primary detection antenna (5) is of the volume type, comprising Helmholtz coils or saddle coils, or a more complex volume geometry, particularly gradiometric geometry, and the step (4) of processing the secondary detection signal comprises a flux-locked loop (FLL) which is provided to linearise the response of the SQUID device (3).

Classes IPC  ?

• G01R 33/32 - Systèmes d'excitation ou de détection, p. ex. utilisant des signaux radiofréquence
• G01R 33/44 - Dispositions ou appareils pour la mesure des grandeurs magnétiques faisant intervenir la résonance magnétique utilisant la résonance magnétique nucléaire [RMN]
• G01R 33/34 - Détails de structure, p. ex. résonateurs

Produits et services

Magnetic resonance imaging [MRI] apparatus, not for medical purposes; Nuclear magnetic resonance [NMR] apparatus not for medical use; Magnetic detectors; Imaging devices for scientific purposes; Electronic imaging devices; Magnetic detection apparatus and instruments. Medical instruments and apparatus, in particular nuclear magnetic resonance equipment and for medical imaging in general; Nuclear magnetic resonance [NMR] apparatus for medical use; Magnetic resonance imaging scanners; Magnetic resonance imaging [MRI] apparatus for medical purposes; Magnetic resonance imaging [MRI] apparatus for medical purposes; Nuclear magnetic resonance installations for medical scanning; MRI diagnostic apparatus; Magnetic treatment apparatus for medical use; Electronic apparatus for medical purposes; Medical diagnostic apparatus for medical purposes; Diagnostic imaging apparatus for medical use; Magnetic field generators for medical use; Sources of magnetic fields for use in medical diagnosis and treatment. Design of magnetic resonance imaging [MRI] apparatus for medical use; Design of nuclear magnetic resonance [NMR] imaging apparatus for medical use; Design and development of diagnostic apparatus; Design and development of medical diagnostic apparatus; Design and development of computer software for use with medical technology; Design of magnetic resonance imaging [MRI] apparatus not for medical use; Design of nuclear magnetic resonance [NMR] imaging apparatus not for medical use; X-ray imaging, other than for medical purposes; Non-medical, ultrasound imaging services.