Koninklijke Philips Corporation N.v.

Holger Timinger

Johannes Adrianus Overweg

Sascha Krueger

Vladimir Pekar

Michael Kaus

Joerg Sabczynski

Hans-Aloys Wischmann

Joern Borgert

Sascha Kruger

The present invention relates to an arrangement () for influencing and/or detecting magnetic particles () in a region of action (), which comprises selection means () for generating a magnetic selection field () having a pattern in space of its magnetic field strength such that a first sub-zone () having a low magnetic field strength and a second sub-zone () having a higher magnetic field strength are formed in the region of action (). The arrangement further comprises drive means () for changing the position in space of the two sub-zones () in the region of action () by means of a magnetic drive field () so that the magnetization of the magnetic material changes locally. The arrangement further comprises receiving means () for acquiring detection signals, which detection signals depend on the magnetization in the region of action (), which magnetization is influenced by the change in the position in space of the first and second sub-zone (). Control means () are further introduced for controlling the selection means () to individually set the gradient strength of at least one of the static magnetic gradient fields () in a desired direction.

Arrangement with variable selection field orientation for magnetic particle imaging

The invention relates to a device and a method for the determination of the position of a catheter in a vascular system (). In this, the measured positions (r, r) of two magnetic localizers at the tip of a catheter are displaced by correction vectors (k, k) while optimizing a quality dimension. The quality dimension includes a component taking account both of the deviation of the measured positions (r, r) from the vascular layout and of the deviation of the associated orientation (r&#x2212;r) 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 (r', r&#x2033;) correspond to the preset fixed distance (d) of the localizers ().

Device and method for the determination of the position of a catheter in a vascular system

The present invention relates to a magnetic resonance examination system () and to a method of operating such a magnetic resonance examination system (). In particular the present invention relates to a magnetic resonance examination system () comprising a superconducting main magnet () surrounding an examination region () and generating a main magnetic field in the examination region (), and further comprising a magnetic field gradient system () selectively causing alternating gradient magnetic fields in the examination region (), said magnetic field gradient system () being coupled to the main magnet (). In order to provide a technique to reliably detect a quench of the superconducting main magnet () of such a magnetic resonance examination system () a detecting device () is suggested for detecting an emerging quench of the main magnet (), said detecting device () being adapted to operate in different modes depending on the mode of operation of the magnetic resonance examination system (e.g. ramp-up, ramp-down or continuous operation).

Detecting quench in a magnetic resonance examination system

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.

Superconductive magnet system for a magnetic resonance examination system

A magnetic resonance examination system () includes a superconducting main magnet () surrounding an examination region () and generating a main magnetic field in the examination region () A magnetic field gradient system () selectively causes alternating gradient magnetic fields in the examination region (). The magnetic field gradient system () is disposed outside of the main magnet (). In order to provide stable operation of the superconducting main magnet () of a magnetic resonance examination system () with such a magnetic field gradient system (), the magnetic resonance examination system () is provided with a predicting device () and a preventing device () The predicting device () predicts the behavior of the main magnet () due to the gradient magnetic fields (e.g., by calculating the expected heat load of the main magnet caused by an imaging protocol) and the preventing device () prevents, based on the predicted behavior of the main magnet (), the main magnet () from quenching.

Prevention quench in a magnetic resonance examination system

The invention relates to a device and a method for correction of the position (x) of a field sensor () measured by means of a magnetic localization device. External field distortions, such as caused for example by the rotating components () of a computer tomograph (), are then determined with the help of reference sensor () placed at a known position. It is possible to deduce, for example, the current angle of rotation (&#x3a6;) of the computer tomograph () from the measurement signals of the reference sensor (). Based on an empirically determined correction (&#x3b4;(x, &#x3a6;)), the uncorrected determined positions (x) of the field sensor () can then be converted to corrected positions (x') in relation to the field distortions. The field generator () and the reference sensor () are preferably fastened to the gantry in order to eliminate the dependency of the field distortions on an inclination of the gantry.

Correction of measured values for a magnetic localization device

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.

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Hamburg, Germany

Holger Timinger