U.S. Philips Corporation

Other

Hans H Tuithof

Johannes J Van Vaals

Hendrik Jan Meulenbrugge

Dietmar W Kunz

Jeroen Snelten

Johannes J Cuppen

William T Dixon

Albertus C Meyer

Jacobus Mulder

Anne J Boerboom

An invasive device which is intended to cooperate with a magnetic resonance imaging apparatus is provided with an RF coil which is situated near a distal part of the invasive device. The RF coil is used so as to visualize the position of a distal end of the invasive device, introduced into an object, in an image of the object. Current induced by an RF field to be generated by the magnetic resonance imaging apparatus develops heat in the electric connection between the RF coil and a control unit, which may be annoying to a patient. In order to counteract the development of heat in the invasive device, the invasive device is provided with a hollow carrier. The electric connection extends through said carrier which is provided with an electrically conductive shield with an additional resistance.

Invasive device for use in a magnetic resonance imaging apparatus

A method of magnetic resonance imaging of a part of the body (106) arranged in a substantially uniform, static magnetic field where, in order to follow a dynamic process in the body, the temporal resolution is enhanced by successively generating MR signals which are associated with only a part of a reference set of lines in the k-space. After the generating and sampling of a series of MR signals associated with the lines of the part of the reference set, a reconstruction set is renewed and an image of the part of the body is reconstructed from the reconstruction set by a processing unit (110) executing a 2D Fourier transformation, said image subsequently being displayed on a monitor (111). In order to counteract motion artefacts, for example echo images of contours of objects in the image, the associated lines of the part of the reference set are uniformly distributed in the k-space during the generating of MR signals.

Method of and device for magnetic resonance imaging of objects

A magnetic resonance device (1) for imaging inter alia human organs by way of magnetic resonance is provided in close proximity with an x-ray imaging device (20). When, for example, in neurosurgery interventional techniques are executed in combination with a magnetic resonance device (1), the organs are suitably visualized but the instruments guided to an organ via an opening in the body are not visible or only hardly so. Prior to the present invention, in order to carry out interventional procedures, the patient would be transported between a room housing magnetic resonance device and a room housing on x-ray device. Transporting the patient over a long distance between two rooms is objectional because of the risk of motion of the instruments lodged within the body of the patient; as such motion could be fatal to the patient. A solution consists in arranging an X-ray device (20) adjacent the MR device (1), so that the patient need be transported a short distance only. Undesirable mutual influencing of the MR device (1) and the X-ray device (20) is counteracted by shielding the static magnetic field of the MR device and the electromagnetic fields generated by the X-ray device.

Magnetic resonance device

An imaging system includes to a magnetic resonance device (1) for imaging inter alia human organs by way of magnetic resonance and an X-ray device for imaging by way of X-ray. When interventional techniques are applied in combination with a magnetic resonance device (1), the organs are suitably visualized, but the instruments guided to an organ via an opening in the body are not visible or only hardly so. These instruments must be imaged by means of an X-ray device (20); the patient must then be transported some distance, for example a few meters, in order to obtain distortion-free images of the instruments. Transporting the patient has some drawbacks. There is a risk of motion of the instruments within the patient and, moreover, the coordinate systems of the MR device (1) and the X-ray device (20) might deviate from one another. A solution consists in arranging the X-ray device (20) immediately adjacent to or in the MR device (1), so that the patient need not be transported at all or only over a small distance. The undesired mutual influencing of the MR device (1) and the X-ray device (20) is counteracted, for example by using a solid-state X-ray detector (22) which includes a solid-state image pick-up device and, for example by making the position of the X-ray tube (40) dependent on the static magnetic field of the magnetic resonance device.

Imaging system comprising magnetic resonance and X-ray imaging devices

A magnetic resonance imaging method is proposed for the following of a dynamic process in a body (5), such as perfusion in the brain by means of a contrast agent such as Gd-DTPA, or the effects of a physical stimulus. The dynamic process is followed by way of a multiple-slice MR measurement through, for example, 10 slices. In accordance with the invention, before or after the injection of the contrast agent, high-resolution reference images of the slices are formed, the same slices being measured with a lower resolution during the perfusion of the contrast agent. Substitution of the low-resolution data in data matrices containing high-resolution data produces, after Fourier transformation, images of the slices in which the measured changes in image intensities due to the contrast medium are reproduced in the high-resolution images.

Magnetic resonance imaging method

The method and device for NMR Fourier zeugmatography utilizes amplitude-modulated r.f. pulses (90.degree. and 180.degree. pulses) for the excitation of nuclear spins and the generating of nuclear spin echo signals. For three-dimensional Fourier zeugmatography, r.f. pulse having a large bandwidth (for example 10-50 kHz) are desired. The use of amplitude-modulated signals then implies an undesirably high peak power of the r.f. generator. In accordance with the invention, use is made of a frequency-modulated signal which can have a substantially constant amplitude and which preferably covers the desired frequency spectrum at a uniform speed.

Method and device for determining an NMR distribution in a region of a

A phantom for NMR apparatus comprises a structure of holes which are to be filled with a contrast medium so that when the phantom is imaged in NMR apparatus, imaging qualities such as resolution, sensitivity, linearity etc. can be read directly or measurements can be performed for this purpose.

Phantom for NMR apparatus

A magnetic quadrupole lens 5 is disposed between an ion source 1 and a sector magnet 2 in a mass spectrometer, and an electric quadrupole lens 4 is disposed between the sector magnet and a detector 3. The powers and polarities of the lenses may be varied to provide a desired degree of dispersion of the ion streams and a desired focal plane orientation coincident with the detector face or plane.

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Eindhoven, Netherlands

Hans H Tuithof