Abstract: The invention relates to an arrangement and a method for determining the spatial distribution of magnetic particles in an examination area. Magnetic field means are used to generate a spatially inhomogeneous gradient magnetic field with at least one region with a low field strength, in which the magnetization of the particles is in a state of non-saturation, whereas they are in a state of saturation in the remaining region. By using change means to shift the area with a low field strength within the examination area, a change in the magnetization of the magnetic particles is brought about which can be detected from outside by detection means and contains information about the spatial distribution of the magnetic particles in the examination area. The magnetic field means or the change means or the detection means or a combination of these means are arranged at least partially on a medical instrument.

Abstract: A transmission path (13) for transmitting high frequency (RF) signals is disclosed, which comprises a plurality of lead segments (20, 21, 22) which are coupled to one another on one end by a capacitive coupling element (30) and on the other end by an inductive coupling element (31) and which each have an effective length of approximately ?i/4, wherein ?i is the wavelength of a differential mode signal to be transmitted over the path (13). By providing these element (30, 31) in the form of distributed elements which electrically extend over at least a part of adjacent lead segments (20, 21; 21, 22) a very thin transmission path (13) can be realized, which is especially suitable for use with invasive catheters. Furthermore, this path (13) can be guided through RF fields of a magnetic resonance (MR) imaging system because common mode resonances are effectively suppressed.

Abstract: The invention relates to a method of determining the spatial distribution of magnetic particles in an examination zone. According to this method a spatially inhomogeneous magnetic field is generated which includes at least one zone (301) in which the magnetization of the particles is in a non-saturated state whereas the particles in the remaining zone are in a saturated state. Shifting this zone within the examination zone produces a change of the magnetization which can be externally detected and contains information concerning the spatial distribution of the magnetic particles in the examination zone.

Abstract: The arrangement (10) is suited for transmitting an informative signal (S1), generated by suitable signal generator (1) at a first electrical site (7a) to a second electrical site (7b). The first electrical site (7a) is electrically connected to the second electrical site (7b) by means of a capacitively coupled transmission line (5a, 5b). In order to enable such capacitively coupled transmission line distributed or lumped capacitors (4a, 4b, 4c, 4d) can be used. The arrangement is connectable to an accessory device (6), which may comprise a spectrometer, a further signal generator, tuning means, etc. The further signal (S2) is generated by the accessory device (6) and transported via the capacitively coupled transmission line (5a, 5b) in a direction from the second electrical site (7b) to the first electrical site (7a). The further signal (S2) can be used for feeding an amplifier (2), or for carrying the signal (S1).

Abstract: The invention relates to a method and an apparatus for influencing magnetic particles in a region of action. With the help of an arrangement that has means for generating magnetic fields, a spatially inhomogeneous magnetic field is generated that has at least one zone (301) in which the magnetization of the particles is in a state of non-saturation, whereas it is in a state of saturation in the remaining zone. By displacing the said zone within the region of action, a change in magnetization is produced that can be detected from outside and that gives information on the spatial distribution of the magnetic particles in the region of action. Alternatively, the displacement may also be repeated so frequently that the region of action heats up. To improve the accessibility of the region of action, the said region is situated outside the arrangement having means for generating magnetic fields.

Abstract: An arrangement for magnetic particle imaging and a method for influencing and/or detecting magnetic particles in a region of action is disclosed, which arrangement comprises: magnetic particles in a region of action, the magnetic particles being influenceable and/or detectable, 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 strengthare formed in the region of action, 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 particles changes locally, wherein each magneticparticle comprises a non-magnetic substrate with a layer of stainless steel.

Abstract: An electrically conductive link (connection lead) or transmission line (13) including at least one transformer (41, 42; 83) for coupling at least two lead segments (51, 52; 81, 82) of the line (13) and for providing safety of the line when guided through a RF field. These lines are especially provided for use with a magnetic resonance (MR) imaging system and for connecting an electrical device (10), especially a catheter or another invasive device for the examination of a human body, to a connection unit (12) such as, for example, a power supply or control unit outside the examination zone (1) without imposing the risk of disturbances and/or destruction of the electrical device and/or the connection unit and of burning a patient (P) by a heating of the line when guided through RF fields.

Abstract: Examining an object wherein magnetic particles are introduced into at least part of a target area of the object under examination, the target area having a first part with a magnetic field strength that keeps magnetic particles in a non-saturated state, and a second part with a second magnetic field strength that keeps the magnetic particles in a saturated state. A superposed oscillating or rotating magnetic field is generated at least partially in the first part-area to cause at least some magnetic particles to oscillate or rotate. The target area is irradiated with electromagnetic radiation and detected radiation includes reflected or scattered electromagnetic radiation, which is modulated by interaction with rotating or oscillating magnetic particles in the target area. The intensity, absorption or polarization of the detected electromagnetic radiation is determined as a function of change in rotation or oscillation of the magnetic particles due to modulation.

Abstract: A magnetic resonance imaging system is provided with one or more electrical accessory devices, for example, catheters (10) or RF surface coils (6), which are intended for use during the examination of an object, as well as with a connection lead (13) which is arranged so as to extend through an examination zone (1) of the magnetic resonance imaging apparatus, which zone can be exposed to an RF field, and to connect the accessory device to a connection unit (12). In order to avoid heating of the connection lead (13) due to common mode currents induced in the connection lead by the RF field, which currents could lead to injury of a patient or damage of the accessory device or the connection unit (12), the connection lead (13) comprises at least two lead segment (131, 132, . . .

Abstract: An arrangement and a method for influencing and/or detecting magnetic particles in a region of action is disclosed, which arrangement 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, 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 particles changes locally, wherein the selection means comprise at least one permanent magnet comprising a high resistive permanent magnet material.

Abstract: A method and an arrangement for separating magnetic particles, magnetic particles and the use of magnetic particles are disclosed wherein the method comprises the steps of: —subjecting the magnetic particles to a first magnetic field such that the particle direction of easy magnetization is oriented parallel to the magnetic field vector of the first magnetic field, —subjecting the magnetic particles to a second magnetic field having an orientation rotated about an angle relative to the magnetic field vector of the first magnetic field, —applying a separating force on the magnetic particles.

Abstract: A method and an arrangement for influencing and/or detecting and/or locating magnetic markers in a region of action is disclosed, which method comprises the steps of: generating a magnetic drive field so that the magnetization of the magnetic marker changes, generating a magnetic selection field having a pattern in space of its magnetic field strength providing a magnetic field gradient in the region of action, acquiring a first signal by means of a first receiving probe and acquiring a second signal by means of a second receiving probe, the first receiving probe and the second receiving probe being located at different locations relative to the region of action, the first signal and the second signal depending on the magnetization of the magnetic marker in the drive field and in the selection field and further depending on the location of the magnetic marker, the magnetic selection field having a first magnetic field strength configuration, repeating at least once the acquisition of the first signal and of t

Abstract: A method and an arrangement for influencing and/or detecting magnetic particles in a region of action of an examination object is disclosed, which method comprises the steps of: generating a magnetic selection field by means of selection means, the 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, changing the position in space of the two sub-zones in the region of action by means of a magnetic drive field generated by drive means so that the magnetization of the magnetic particles change locally, acquiring signals by means of receiving means, which 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, wherein the selection means and/or the drive means and/or the receiving means are provided at least partly

Abstract: The invention relates to a method of determining a spatial distribution of magnetic particles in an examination area, in which a magnetic field is generated which has a first part-region having a relatively low magnetic field strength and a second part-region having a relatively high magnetic field strength. The position of the two part-regions is changed, as a result of which the magnetization in the examination area changes, and real measured values which depend on the change in magnetization are recorded. A dependence distribution which depends on a spatial distribution of magnetic particles is then determined such that a sum which comprises as summands a) the difference of the real measured values from fictitious measured values which are determined by applying a transfer function to the dependence distribution, and b) the product of a regularization parameter and of a regularization value which is determined by applying the regularization functional to the dependence distribution, is minimized.

Abstract: An arrangement and a method for influencing and/or detecting magnetic particles in a region of action is disclosed, which arrangement 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,—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 particles changes locally,—receiving means for acquiring signals, which 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, wherein the selection means and/or the drive means and/or the receiving means comprises at least partially a litz wire/stranded wire.

Abstract: An arrangement and a method for detecting and/or locating magnetic material, and the use of an arrangement in the examination of buildings is disclosed, which arrangement 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, 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, 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, wherein the magnetic selection field comprises at least a time-variable field component varying at a frequency of at least about 100 Hz.

Abstract: An arrangement and a method for influencing and/or detecting magnetic particles in a region of action is disclosed, which arrangement 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, 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 particles changes locally, receiving means for acquiring signals, which 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, wherein the arrangement comprises a coil arrangement comprising a surrounding coil and a magnetic field generator such that the surrounding coil almost completely surrounds the magnetic field g

Abstract: The present invention relates to a catheter (6) comprising: a connector (65, 66) at a proximal side of the catheter for connecting the catheter to an external signal transmission/receiving unit (10) for transmitting and/or receiving signals, an electrode (63, 64) at a distal side of the catheter, and an electrical connection including an electrical wire (61, 62) for electrically connecting the electrode and the connector for the transmission of signals between the electrode and the connector, wherein the electrical connection has a high electrical resistance of at least 1 k?, in particular of at least 5 k?. Thus, the present invention provides a solution to prevent excessive heating during EP interventions under MR guidance by using by using highly resistive wires and or lumped resistors as connections within catheters.

Abstract: An arrangement and a method for influencing and/or detecting magnetic particles in a region of action is disclosed, which arrangement 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,—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 particles changes locally, wherein the selection means comprises at least one permanent magnet wherein the permanent magnet is at least partially shielded by an electrically high conductive shielding means.

Abstract: An arrangement and a method for influencing and/or detecting and/or locating magnetic particles in a region of action is disclosed, which arrangement comprises: —drive means for generating a magnetic drive field so that the magnetization of the magnetic particles changes, wherein the magnetic particles comprise at least a first and a second magnetic particle, —the receiving means comprising at least a first receiving probe providing a first signal (231?) and a second receiving probe providing a second signal—detection means for determining signal features arising from the first particle in the first signal and in the second signal.