Abstract: The invention relates to a medical imaging device which includes a central control unit and a number of peripheral devices connected to the central control unit, one or more of the peripheral devices being provided with separate emergency control means which are arranged to allow the peripheral devices in question to function independently from the central control unit, the medical imaging device also being provided with an emergency control unit for controlling the emergency control means. The invention also relates to a method for use of the medical imaging device according to the invention in a safety critical environment and to a computer program for carrying out the method according to the invention.

Abstract: The invention relates to a radio-frequent (RF) coil system (17, 17?) for use in a magnetic resonance imaging (MRI) system. The RF coil system comprises at least one main coil (35) for transmitting an RF magnetic field (B1) into and/or receiving an RF magnetic field (B1?) from an examination volume (3) of the MRI system. The main coil has a coil axis (36), which is or is to be oriented parallel to a main magnetic field (Bo) in the examination volume (3), and at least one electrical conductor (37, 39) which extends mainly parallel to the coil axis. According to the invention, the RF coil system comprises an auxiliary coil (45, 47) which is assigned to said conductor of the main coil. The auxiliary coil has two electrical conductors (49, 51) which extend mainly parallel to the coil axis and on opposite sides of said conductor of the main coil. A distance between the two conductors of the auxiliary coil and the conductor of the main coil is small relative to a main dimension (L) of the main coil.

Abstract: A CT scanner comprising a stator and a rotor having an axis of rotation mounted to the stator so that the rotor is rotatable about the axis of rotation comprising: an X-ray source mounted to the rotor, said X-ray source having a focal spot from which X-rays emanate; an X-ray detector array comprising a matrix of rows and columns of X-ray detectors; anti-scattering (AS) material for absorbing X-rays positioned between columns of the X-ray detectors; and anti-scattering (AS) material for absorbing X-rays positioned between rows of the X-ray detectors, whereby the AS material is located between every other row and/or column of detectors, respectively. Furthermore, the thickness and/or height of the foils between rows may be different from the thickness and/or height of the foils between columns.

Abstract: A magnetic resonance imaging apparatus includes a main magnet (12) for generating a main magnetic field in an examination region (14), a plurality of gradient coils (22) for setting up magnetic field gradients in the main field, an RF transmit coil for transmitting RF signals into the examination region to excite magnetic resonance in a subject disposed therein, and an RF receive coil (16) for receiving RF signals from the subject. The RF receive coil includes a first loop (101) and a second loop (102), the first and second loops being disposed substantially in a similar plane (x-z). Also included is a signal combiner (120) for combining the signals received by the first and second loops in quadrature.

Abstract: A magnetic resonance apparatus includes a main magnetic field generating assembly (12) located in a magnetic resonance suite generates a substantially spatially constant main magnetic field through at least a portion of a subject in an imaging region. A gradient field generating assembly (16) overlays spatially variant gradient magnetic fields onto the main magnetic field. A radio frequency assembly (22) excites magnetic resonance in dipoles of a subject in the imaging region. A receiver (36) receives magnetic resonance signals from resonating dipoles in the imaging region. Radio frequency transponders (60) are affixed to objects (22, 104, 106, 108, 110, 114) in the magnetic resonance suite. The transponders (60) are interrogated by a reader/writer (62) to determine which coils are in the bore (14) and whether other coils and objects are outside of a safety threshold (116).

Abstract: The present invention relates to a method for monitoring a system in which a datum-line display (11) is generated on a viewing screen (4) for at least one parameter of the system, comprising a baseline (14) that represents a base value for the parameter concerned, a continuous curve (15) that represents a variation with time of the values of the parameter concerned and is normal with respect to the baseline (14), and a deviation bar (16) that represents the instantaneous deviation between the base value and current parameter value and is normalized with respect to the baseline (14).

Abstract: The invention relates to an MRI system (1) comprising an examination volume (11), a main magnet system (13) for generating a main magnetic (field (B0) in the examination volume, a gradient magnet system (19) for generating gradients of the main magnetic field, and an anti-vibration system (39) for reducing vibrations of the gradient magnet system. According to the invention the anti-vibration system comprises a gyroscope (41) which is mounted to the gradient magnet system. As a result of the gyroscopic effect of the gyroscope, the vibrations of the gradient magnet system are effectively reduced. In an open type MRI system (1) according to the invention, a separate gyroscope (41, 43) is mounted to each of the two portions (21, 23) of the gradient magnet system (19), and each gyroscope has an axis of rotation (61) parallel to the main direction (Z) of the main magnetic field (B0).

Abstract: An MR device for MR imaging includes an RF coil system. In order to enable switching to and fro between different applications in such an MR device without having to move the patient so as to position a new RF coil system, it is proposed to provide the RF coil system for the transmission and/or reception of RF signals with at least two RF coil arrays which are integrated in one coil former and have been optimized for different applications, each RF coil array comprising at least two RF coils which are decoupled from one another.

Abstract: An apparatus for producing a corrected reconstructed image from magnetic resonance imaging data acquired by a magnetic resonance imaging scanner (10) includes a reconstruction processor (44) that reconstructs a corrected reconstructed image from acquired magnetic resonance imaging data. A parameters calculation processor (52) determines at least one characteristic of the imaging subject. A correction pattern adjustment processor (54) selects a correction pattern from a family of stored correction patterns based on the at least one characteristic. An image correction processor (56) corrects the uncorrected reconstructed image using the selected correction pattern to produce the corrected reconstructed image.

Abstract: In a magnetic resonance imaging method magnetic resonance signal samples are received for a predetermined field of view by a receiving antenna having a spatial sensitivity profile. The sampling in the k space corresponds to the predetermined field of view in the geometrical space. Folded-over images having folded-over pixel values are reconstructed from the sampled magnetic resonance signals. Pixel contributions for spatial positions within the predetermined field of view are calculated from the folded-over pixel values and the spatial sensitivity profile of the receiver antenna. The magnetic resonance image is formed from the pixel contributions for spatial positions within the predetermined field of view. Thus, aliasing or fold-over artefacts caused by a field of view that is too small are avoided.

Abstract: A magnetic resonance system and method are described for performing an improved magnetic resonance ductography which gives better resolution and higher signal to noise ratio than known systems and methods. Use is made of a small coil together with a post processing technique addressed to the improvement of the sensitivity of the coil. The magnetic resonance sequence used is a fat suppressed T2 weighted turbo spin echo sequence.

Abstract: The invention relates to a computerized tomography method, in which an examination area is scanned radiographically along a helical trajectory by a conical beam. The radiation transmitted through the examination area is measured by means of a detector unit, wherein the absorption distribution in the examination area is reconstructed exactly or at least quasi-exactly from these measured values. Reconstruction uses redundant measured values and comprises derivation of the measured values from parallel rays of different projections, integration of these values along ?-lines, weighting of these values and back-projection.

Abstract: A conebeam computed tomography scanner (10) acquires conebeam projection data along a generally helical source trajectory around an examination region (14). An exact reconstruction processor (40) includes a convolution processor (42) and an aperture weighted backprojection processor (46, 66). The convolution processor (42) performs at least one convolution of the acquired projection data. The convolving operates on projection data falling within an exact reconstruction window (38) and on at least some redundant projection data falling outside the exact reconstruction window (38) to produce convolved projection data.

Abstract: In a method for magnetic resonance imaging of at least a portion of a body placed in a stationary and substantially homogeneous main magnetic field, the body is subjected to a sequence of RF and magnetic field gradient pulses during an interval TSE, thereby generating a plurality of spin echo signals, which are measured and processed for reconstruction of an image. Thereafter, during an interval TDRV, an additional spin echo is generated by subjecting the body to at least one further refocusing RF pulse and/or magnetic field gradient pulse, and a RF drive pulse (?X) is irradiated at the time of this additional spin echo. In order to provide a fast and reliable method for T1-weighted imaging, which gives a high T1 contrast and also a sufficient signal-to-noise ratio, the phase of the RF drive pulse (?X) is selected such that nuclear magnetization at the time of the additional spin echo is transformed into negative longitudinal magnetization.

Abstract: A medical examination device (1) comprising an examination space (3), a combination of a frame (5) and a patient table (4), and rack (8) which can be driven by a drive (9, 10) to displace a patient on the patient table into and out of the examination space. The rack comprises an elongated push-pull member (8) which is connected to the patient table and which has a length that exceeds the length of the patient table. As a result, the patient table can be displaced from the frame into the examination space over a distance that is larger than the length of the patient table.

Abstract: The invention relates to an MR arrangement which includes a medical instrument (3), an RF arrangement (17) which is provided thereon and in which at least one microcoil (1) and a capacitor (2) are connected so as to form a resonant circuit, and also an optical signal lead (4) via which a light signal is applied to the RF arrangement. In order to achieve simple and fast determination of the position of the medical instrument (3) within the examination zone of an MR apparatus, the invention proposes to provide a modulator (20) for modulating the light signal applied to the RF arrangement and also an optoelectrical converter (5) which converts the modulated light signal into an electrical signal and is coupled to the resonant circuit in such a manner that the resonant circuit is triggered by the electrical signal from the optoelectrical converter (5) so as to emit an RF field.

Abstract: A magnetic resonance imaging apparatus includes an RF coil system with M RF coils (11–18) for detecting RF signals from a region of interest, M being an integer larger than 2, and N receiver channels (C1–C4) for receiving and processing the detected RF signals, N being an integer larger than 1 and smaller than M. At least two RF coils (12, 16; 14, 18) are combined for reception of RF signals of said RF coils with a single receiver channel. The at least two RF coils are selected so as to provide maximum spatially varying coil sensitivities along the principal axis for coil sensitivity encoding. The proposed MRI apparatus provides an optimal solution enabling it to be used with the SENSE method. The individuality is maximized along the preferred or actual sense reduction direction as is spatial distinctness along the axes of primary clinical interest.

Abstract: A magnetic resonance imaging system comprises means for generating a main magnetic field with a main magnetic field strength an a plurality of magnetic resonance signal receiving positions, provided by one or more receiver antennae. The receiver antennae or coils have a spatial sensitivity profile for acquiring magnetic resonance signals at a predetermined degree of undersampling. Further means for reconstructing a magnetic resonance image from the set of undersampled magnetic resonance signals and the spatial sensitivity profiles are provided. In addition, means are provided for determining the degree of undersampling (R) in dependency of the given main field strength (B0) and the selected field-of-view (FOV).

Abstract: A magnetic resonance imaging method comprises application of a pulse sequence which includes one or more pulses. The pulse sequence having an intrinsic scan time based on a full sampling rate in k-space for a predetermined full ‘field-of-view’ and a reference temporal pulse shape of the magnetic gradient pulses. A series of magnetic resonance signals is acquired by means of a receiver antennae system having a spatial sensitivity profile. Undersampled signal acquisition is applied to acquire undersampled magnetic resonance signals at a predetermined reduced sampling rate in k-space, the sampling rate being reduced by a reduction factor relative the full sampling rate. The pulse sequence being is during an actual signal scan time is applied. The actual signal scan time being larger than the intrinsic signal scan time times the reduction factor.

Abstract: The invention relates to a method for magnetic resonance imaging (MRI) of at least a portion of a body placed in a stationary and substantially homogeneous main magnetic field. The method comprises the steps of subjecting the body to a diffusion-weighting sequence (DW1), generating a train of MR echoes (E1, E2, E3, E4, E5) by an imaging sequence (EPI1), and measuring this train of MR echoes. These steps are repeated until a complete imaging data set with a sufficient number of phase-encoding steps is measured. Thereafter, the imaging data set is corrected for macroscopic motions by means of an individual phase-correction of each train of MR echoes. Finally, an image is reconstructed from the imaging data.