Abstract: The present invention relates to an arrangement (10) for influencing and/or detecting magnetic particles (100) in a region of action (300), which comprises selection means (210) for generating a magnetic selection field (211) having a pattern in space of its magnetic field strength such that a first sub-zone (301) having a low magnetic field strength and a second sub-zone (302) having a higher magnetic field strength are formed in the region of action (300). The arrangement further comprises drive means (220) for changing the position in space of the two sub-zones (301, 302) in the region of action (300) by means of a magnetic drive field (221) so that the magnetization of the magnetic material changes locally. The arrangement further comprises receiving means (230) for acquiring detection signals, which detection signals depend on the magnetization in the region of action (300), which magnetization is influenced by the change in the position in space of the first and second sub-zone (301, 302).

Abstract: The invention relates to a device and a method for the determination of the position of a catheter in a vascular system (8). In this, the measured positions (r1, r2) of two magnetic localizers at the tip of a catheter are displaced by correction vectors (k1, k2) while optimizing a quality dimension. The quality dimension includes a component taking account both of the deviation of the measured positions (r1, r2) from the vascular layout and of the deviation of the associated orientation (r2?r1) from the orientation of the vascular layout according to a vascular map. In addition, the quality dimension may include components which evaluate the measured shape of the catheter compared to the vascular map. An additional correction step can further ensure that the corrected positions (r1?, r2?) correspond to the preset fixed distance (d) of the localizers (4, 5).

Abstract: The present invention relates to a magnetic resonance examination system (10) and to a method of operating such a magnetic resonance examination system (10). In particular the present invention relates to a magnetic resonance examination system (10) comprising a superconducting main magnet (20) surrounding an examination region (18) and generating a main magnetic field in the examination region (18), and further comprising a magnetic field gradient system (30) selectively causing alternating gradient magnetic fields in the examination region (18), said magnetic field gradient system (30) being coupled to the main magnet (20).

Abstract: A superconductive magnet system with a super conductive magnet is provided with a cooling system. A thermal switch is configured to thermally (de)couple the superconductive magnet from/to the cooling system so that the magnet can be decoupled from the cooling system e.g. in the event of a quench.

Abstract: A magnetic resonance examination system (10) includes a superconducting main magnet (20) surrounding an examination region (18) and generating a main magnetic field in the examination region (18) A magnetic field gradient system (30) selectively causes alternating gradient magnetic fields in the examination region (18). The magnetic field gradient system (30) is disposed outside of the main magnet (20). In order to provide stable operation of the superconducting main magnet (20) of a magnetic resonance examination system (10) with such a magnetic field gradient system (30), the magnetic resonance examination system (10) is provided with a predicting device (91) and a preventing device (92) The predicting device (91) predicts the behavior of the main magnet (20) due to the gradient magnetic fields (e.g.

Abstract: The present invention relates to an arrangement (10) for influencing and/or detecting magnetic particles in a region of action (300). The arrangement (10) comprises selection means (210) for generating a magnetic selection field (211) having a pattern in space of its magnetic field strength such that a first sub-zone (301) having a low magnetic field strength and a second sub zone (302) having a higher magnetic field strength are formed in the region of action (300), drive means (220) for changing the position in space of the two sub-zones (301, 302) in the region of action (300) by means of a magnetic drive field (221) so that the magnetization of the magnetic material changes locally, and receiving means (230) for acquiring detection signals, which detection signals depend on the magnetization in the region of action (300), which magnetization is influenced by the change in the position in space of the first and second sub-zone (301, 302).

Abstract: The present invention relates to an arrangement (10) for influencing and/or detecting magnetic particles (100) in a region of action (300), which comprises selection means (210) for generating a magnetic selection field (211) having a pattern in space of its magnetic field strength such that a first sub-zone (301) having a low magnetic field strength and a second sub-zone (302) having a higher magnetic field strength are formed in the region of action (300). The arrangement further comprises drive means (220) for changing the position in space of the two sub-zones (301, 302) in the region of action (300) by means of a magnetic drive field (221) so that the magnetization of the magnetic material changes locally. The arrangement further comprises receiving means (230) for acquiring detection signals, which detection signals depend on the magnetization in the region of action (300), which magnetization is influenced by the change in the position in space of the first and second sub-zone (301, 302).

Abstract: An electromagnet comprises: a ferromagnetic core (50, 72); electrically conductive windings (34, 76) disposed around the ferromagnetic core such that current flowing in the windings magnetizes the ferromagnetic core; and a superconducting film (60, 80, 82) arranged to support eddy current cancelling supercurrent that suppresses eddy current formation in the ferromagnetic core when the windings magnetize the ferromagnetic core. A magnetic resonance scanner embodiment includes a main magnet (20) generating a static magnetic field and a magnetic field gradient system (30) with a plurality of said electromagnets (34, 50, 60) configured to superimpose selected magnetic field gradients on the static magnetic field.

Abstract: A magnet system, in particular for a magnetic resonance examination system, comprises a superconductive main magnet having a near group of coil windings and a remote group of coil windings. A gradient coil system forms a source of power dissipation into at least part of the coil windings. The near group of coil windings and the remote group of coil windings are near and remote from the source of power dissipation, respectively A cooling system has a high-temperature cooling station and a low-temperature cooling station. The high-temperature cooling station cools mainly the near group of coil windings. The low temperature cooling station cools mainly the remote group of coil windings. The near and remote group optionally are made of different superconductive materials. Thus, additional degrees of freedom are achieved which allow less expensive magnet design.

Abstract: The present invention relates to a magnetic resonance examination system (10) comprising a superconducting main magnet (20) surrounding an examination region (18) and generating a main magnetic field in the examination region (18), and further comprising a magnetic field gradient system (30) selectively causing alternating gradient magnetic fields in the examination region (18), said magnetic field gradient system (30) being disposed outside of the main magnet (20).

Abstract: The invention relates to a pointing device (40) for indicating the spatial position of markers (2) to a localization system (10). The pointing device (40) comprises a sensor (42) that detects if a definite interaction with the marker (2) takes place. The sensor (42) may for example be a pressure sensor (42) that determines if the contact force exceeds a threshold which could lead to undesired shifts of the marker (2). The pointing device (40) is used to determine the spatial coordinates of the marker (2), which can then be registered with the image coordinates of the marker (2) in a stored image, e.g. a CT-image.

Abstract: The present invention relates to a magnetic resonance examination system (10) and to a method of operating such a magnetic resonance examination system (10). In particular the present invention relates to a magnetic resonance examination system (10) comprising a superconducting main magnet (20) surrounding an examination region (18) and generating a main magnetic field in the examination region (18), and further comprising a magnetic field gradient system (30) selectively causing alternating gradient magnetic fields in the examination region (18), said magnetic field gradient system (30) being coupled to the main magnet (20).

Abstract: A superconductive magnet system with a super conductive magnet is provided with a cooling system. A thermal switch is configured to thermally (de)couple the superconductive magnet from/to the cooling system so that the magnet can be decoupled from the cooling system e.g. in the event of a quench.

Abstract: The invention relates to a device and a method for correction of the position (x) of a field sensor (4) measured by means of a magnetic localization device. External field distortions, such as caused for example by the rotating components (1a, 1b) of a computer tomograph (1), are then determined with the help of reference sensor (3) placed at a known position. It is possible to deduce, for example, the current angle of rotation (?) of the computer tomograph (1) from the measurement signals of the reference sensor (3). Based on an empirically determined correction (?(x, ?)), the uncorrected determined positions (x) of the field sensor (4) can then be converted to corrected positions (x?) in relation to the field distortions. The field generator (2) and the reference sensor (3) are preferably fastened to the gantry in order to eliminate the dependency of the field distortions on an inclination of the gantry.

Abstract: The invention relates to a method of segmenting a three-dimensional structure from a three-dimensional, and in particular medical, data set while making allowance for user corrections. The method is performed with the help of a deformable three-dimensional model whose surface is formed by a network of nodes and mashes that connect these nodes. Once the model has been positioned at the point in the three-dimensional data set at which the structure to be segmented is situated and positions of nodes have, if necessary, been changed by known methods of segmentation, any desired nodes can be displaced manually. The nodes of the model are re-calculated by making weighted allowance for the nodes that have been displaced manually.

Abstract: The invention relates to a device and a method for the determination of the position of a catheter in a vascular system (8). In this, the measured positions (r1, r2) of two magnetic localizers at the tip of a catheter are displaced by correction vectors (k1, k2) while optimizing a quality dimension. The quality dimension includes a component taking account both of the deviation of the measured positions (r1, r2) from the vascular layout and of the deviation of the associated orientation (r2?r1) from the orientation of the vascular layout according to a vascular map. In addition, the quality dimension may include components which evaluate the measured shape of the catheter compared to the vascular map. An additional correction step can further ensure that the corrected positions (r1?, r2?) correspond to the preset fixed distance (d) of the localizers (4, 5).

Abstract: The invention relates to a device and a method for correction of the position (x) of a field sensor (4) measured by means of a magnetic localization device. External field distortions, such as caused for example by the rotating components (1a, 1b) of a computer tomograph (1), are then determined with the help of reference sensor (3) placed at a known position. It is possible to deduce, for example, the current angle of rotation (?) of the computer tomograph (1) from the measurement signals of the reference sensor (3). Based on an empirically determined correction (?(x, ?)), the uncorrected determined positions (x) of the field sensor (4) can then be converted to corrected positions (x?) in relation to the field distortions. The field generator (2) and the reference sensor (3) are preferably fastened to the gantry in order to eliminate the dependency of the field distortions on an inclination of the gantry.

Abstract: The invention relates to a navigation system for navigating a catheter (3) in a vascular system (10), in which the current spatial position of the catheter (3) is continually measured by a locating device (2). The temporal sequence of the position signals obtained in this way is subjected to a filtering operation in order to compensate for cyclic intrinsic movements of the vascular system which are caused for example by the heartbeat. The filtering may comprise the suppression of amplitude maxima in the frequency spectrum at the heartbeat frequency. Furthermore, the filtering may comprise the calculation of a center of the trajectory in time windows of the length of the heartbeat.

Abstract: The invention relates to a device and a method for navigating a catheter in the vessel system or an intervention needle in an organ of a patient that is subject to a spontaneous movement due to heartbeat and/or respiration. In this connection, a movement model (11) that describes the displacement of points in the vessel system with respect to a reference phase (E0) of the spontaneous movement is kept ready in the memory of a data processing device (10). The spatial positions and orientations of the instrument (4) measured by a locating device (2) in the vessel system of the patient (3) and also the ECG values (E) recorded in parallel therewith are converted by the data processing device (10) with the aid of the movement model (11) into a movement-compensated position (r+?) of the instrument that can then be displayed in a static vessel or organ map (12). The movement model (11) can be obtained from a series of three-dimensional recordings of the vessel system.

Abstract: The invention relates to a catheter system comprising a first, outer catheter (1) and a second catheter element contained in it, which can particularly be a guide wire (2). A respective active localizer (4, 5) is placed on the first and on the second catheter element (1, 2), for example sensors of a magnetic tracking system. The first catheter element (1) preferably has a fixing device (3), by means of which it can be fixed relative to the vascular system (7). If the guide wire (2) is, for example, to be navigated through a stenosis (6), the position of its localizer (5) relative to the localizer (4) is measured on the catheter element at rest (1), so that its position relative to the vessel (7) is known. Since interference factors such as organ movement balance each other during the measurement of the relative position of the localizers (4, 5), the navigation can be carried out with very high accuracy.