199 results about "Magnetic resonance scanner" patented technology

A system for combining electromagnetic position and orientation tracking with magnetic resonance scanner is provided. One embodiment includes a magnetic resonance scanner defining a reference coordinate system for scanning a target. Coupled to the magnetic resonance scanner is a magnetic field source which produces a magnetic field. The magnetic field is sensed by a magnetic field sensor which produces a signal proportional to the magnetic field. The magnetic field sensor has a location relative to the reference coordinate system. The location of the magnetic field sensor relative to the reference coordinate system of the magnetic resonance scanner is determined by a location tracking device using at least a line segment model of the magnetic field source and the signal from the magnetic field sensor.

In a method and control device for determining the position in at least one spatial direction of a local coil on a patient table in a scanner of a magnetic resonance tomography apparatus, a radio-frequency signal is emitted in the presence of a magnetic field gradient applied in the appertaining spatial direction and a signal profile is measured by the local coil along the magnetic field gradient. The signal profile is acquired for each of a number of positions of the patient table relative to the scanner along the magnetic field gradient. Based on the measured signal profile the position of the local coil is determined.

A motion tracking system for dynamic tracking of and compensation for motion of a patient during a magnetic resonance scan comprises a first camera positioned to view an optical marker along a first line of sight; a second camera positioned to view the optical marker along a second line of sight; and a computer system configured to analyze images generated by the first and second cameras to determine changes in position of the optical marker, and to generate tracking data for use by a magnetic resonance scanner to dynamically adjust scans to compensate for the changes in position of the optical marker, wherein the computer system is configured to dynamically adapt its image analysis to utilize images from all cameras that are currently viewing the optical marker.

A hybrid imaging system and a patient bed for same are disclosed. The hybrid imaging system includes a magnetic resonance scanner and a second modality imaging system spaced apart from the magnetic resonance scanner by a gap. In some embodiments, the gap is less than seven meters. The patient bed is disposed at least partially in the gap between the magnetic resonance scanner and the second modality imaging system, and includes a linearly translatable patient support pallet aligned to be selectively moved into an examination region of the magnetic resonance scanner for magnetic resonance imaging and into an examination region of the second modality imaging system for second modality imaging. In some embodiments, a linear translation range of the linearly translatable pallet is less than five times a length of the patient support pallet along the direction of linear translation.

The invention discloses a multi-b-value DWI (diffusion weighted image) noise reduction method based on mutual information. The method comprises steps as follows: acquiring to-be-tested multi-b-value DWIs in multiple diffusion sensitive gradient directions by a magnetic resonance scanner; performing preprocessing such as head movement correction, eddy current correction and the like on the images; estimating different b-value image signal-to-noise ratios; performing noise reduction processing on the images through setting parameters of an optimal noise reduction algorithm so as to acquire DWIs with higher signal-to-noise ratios. The method fully considers features of different images, and three-dimensional structural features of the processed images are reserved as many as possible while noises are eliminated. During establishment of a high-order complex model, different b images have higher image quality, so that acquired high-order parameter images can have smaller errors and fewer singular values. The method can be better applied to preprocessing of a high-order model imaging technology and plays an active role in further research on white matter fiber structures.

A hybrid imaging system includes a magnetic resonance scanner and a second modality imaging system disposed in the same radio frequency isolation space. The second modality imaging system includes radiation detectors configured to detect at least one of high energy particles and high energy photons. In some embodiments a retractable radio frequency screen is selectively extendible into a gap between the magnetic resonance scanner and the second modality imaging system. In some embodiments shim coils are disposed with the magnetic resonance scanner and are configured to compensate for distortion of the static magnetic field of the magnetic resonance scanner produced by proximity of the second modality imaging system.

The present invention relates to a method and apparatus for imaging the mechanical properties of the prostate of a patient non-invasively. The apparatus generally comprises a magnetic resonance scanner, a vibration assembly coupled to the perineal region of the patient, and a driver that drives the mechanical exciter. The method generally comprises positioning the vibration assembly against the perineal region of the patient, vibrating the mechanical exciter to cause deformational excitation of a tissue region contacted in the perineum, capturing a series of images in time (snapshots) of the tissue region using the MR scanner, and finally processing the displacement images to generate maps of mechanical properties of images tissue.

In a contacting system and method for contacting magnetic resonance local coils with a unit for additional signal processing of a magnetic resonance data acquisition unit, a number of coil coupler elements are electrically connected with the magnetic resonance local coils and apparatus coupler elements are mounted at the magnetic resonance tomograph, and are electrically connected with a unit for signal processing. The coil coupler elements and the apparatus coupler elements are fashioned so that, given a movement of the local coils along a movement path in the magnetic resonance data acquisition unit, a successive contacting of at least a portion of the coil coupler elements with apparatus coupler elements ensues at least over a specific path segment of the movement.

An embodiment of the invention relates to the generation of MR images of a volume section within an examination object by way of a magnetic resonance scanner. In at least one embodiment, the following steps are performed: generating at least one of the MR images; automatically performing a number of quality inspections on the at least one MR image; and, should one of these quality inspections fail, an action is automatically performed in order to improve a quality when generating more of the MR images.

A whole-body coil arrangement for an open magnetic resonance scanner for use with a second diagnostic and/or therapeutic modality is proposed. The whole-body coil arrangement includes at least one coil conductor and a radio-frequency shield. The whole-body coil arrangement is embodied at least in part as essentially transparent to the second modality.

Disclosed is a method and system for acquiring absolute temperature imagery using an MR scanner. The method involves using the RF coil as a passive antenna, and performing radiometric measurements of the noise variance of the target within the field of view of the RF coil. The noise variance corresponds to the absolute temperature of the volume within the field of view of the RF coil. The room of the MR scanner is used for electromagnetic shielding during the acquisition of radiometric data. This method may be performed with minimal or no add-ons to existing MR scanner hardware. Disclosed are a method for calibrating an MR scanner for radiometric temperature measurements, and a method for acquiring and generating thermal imagery with a calibrated MR scanner.

A method and magnetic resonance tomography system to generate magnetic resonance image data of an examination subject, raw imaging data are acquired from multiple slices of a predetermined volume region of the examination subject using local coils during a table feed in the magnetic resonance scanner. Image data of the slices are reconstructed on the basis of the raw imaging data. A normalization of the image data is subsequently implemented on the basis of measured coil sensitivity data of the local coils that are used.

In a method for determination of a position of a local coil on a bed in at least one spatial direction within a magnetic resonance scanner, a signal intensity value is initially, extracted from magnetic resonance measurements implemented with the appertaining local coil for acquisition of magnetic resonance images of an examination subject and/or for measurement of further system parameters at each of various positions of the recumbent bed relative to the tomograph. The functional dependency of the extracted signal intensity values on the position of the bed relative to the scanner is then determined. The position of the local coil on the bed is determined on the basis of the determined functional dependency. A corresponding control device for a magnetic resonance system and a computer program product implement the method.

In a method and magnetic resonance apparatus for segmenting image data of an examination object, raw data of the examination object are achieved with the operation of a magnetic resonance scanner. Quantitative image data of the examination object are then calculated in a processor from the raw data. At least one physical variable of the examination object is quantitatively ascertained pixelwise and is displayed. The quantitative image data are segmented for identification of predetermined objects in the quantitative image data, and displayed in a display unit.

The invention relates to the image processing and medical instrument technology field and provides a burgeoning parameter extraction method of biological tissue anisotropy detection, wherein the method is used for clinic application. An analysis method of reconstructing and quantizing a clear, refine and highly-stable biological-tissue microcosmic anisotropy characteristic and a correlation apparatus are obtained. In a technical scheme used in the invention, based on the kurtosis-tensor fractional anisotropy microstructure characteristic extraction method, a subject collects multiple b value diffusion weight images of tissues along a plurality of diffusion sensitivity gradient directions on a magnetic resonance scanner; after the diffusion weight images are preprocessed, in an individual space, a second-order diffusion tensor and a fourth-order kurtosis tensor matrix reflecting a water molecule diffusion distribution probability density function characteristic in the tissues are acquired through fitting; through matrix operation, the corresponding fractional anisotropy FA and kurtosis tensor fractional anisotropy KTFA are acquired; and combining a characteristic parameter, a nerve fiber microstructure characteristic is acquired. The method and the apparatus are mainly used in medical equipment designing and manufacturing.

The invention relates to the technical field of medical instruments, provides a novel practical method for extracting MRI (magnetic resonance imaging) parameters of structural abnormality of white matters of a human brain, and aims to achieve the purpose of objectively evaluate the lesion degree by analyzing anisotropy of tissues through a certain characteristic extraction method. The invention adopts the technical scheme that the method for extracting high-order tensor characteristic parameters of diffusion kurtosis tensor imaging comprises the following steps: a subject collects diffusion weighted signals of tissues along a plurality of directions on a magnetic resonance scanner, then a second-order or fourth-order tensor that reflects diffusion and distribution probability density function of water molecules in the tissues can be obtained through fitting, and lesion characteristics of diffusion and distribution abnormality of the water molecules, caused by structural abnormality of the tissues, can be obtained through certain tensor analysis, wherein parameters from two different angles, including diffusion coefficient and kurtosis coefficient, are mainly included. The invention is mainly applied to design and manufacture of medical instruments.

The invention relates to a local coil (1) with a magnetic resonance antenna group (2) comprising a plurality of antenna turns (3, 3A, 3E) arranged in adjacent rows (SR1, SR2, SR3) ), the antenna turns arranged adjacent to each other are inductively decoupled from each other through geometric overlap (UX, UZ), and the antenna turns are staggered in alternate directions (R1, R2, R3), so that two in a row The overlapping area of ​​the antenna turns is staggered from the overlapping area of ​​two antenna turns in an adjacent row, at least some of the antenna turns are designed to compensate for the stagger, so that they are redrawn as different areas and thus the antenna lines Adjacent rows of turns in the stagger direction terminate substantially at the front end and at the rear end, respectively, on a straight line ( L1 , L2 ) transverse to the stagger direction. The invention also relates to a magnetic resonance apparatus with such a local coil, a method for constructing such a local coil and a method for measuring magnetic resonance signals.

A method for compensating for respiratory motion of a structure imaged by a magnetic resonance (MR) scanner, such as heart, is disclosed. The method comprises obtaining a sequence of navigator samples (22) representative of the progressive displacement of the structure during a first time interval (20), and adjusting a waveform (14) of predefined initial parameters to follow the sequence of navigator samples. During a second time interval (24) which follows the first time interval and during which the magnetic resonance scanner takes a number of image projection views or lines (17), the expected respiratory displacement of the structure is estimated at the times that the image projection lines are taken, by extrapolating the waveform model and estimating the displacements (26) predicted by the extrapolated waveform, so that the position at which the image projection lines are taken can be adjusted to compensate for the respiratory motion, so as to yield a sharper magnetic resonance image.

The invention discloses a diffusion-weighted imaging method comprising the following steps: a plurality of b-value DWI images of a testee are collected via a magnetic resonance scanner, and noise reduction operation is performed on the DWI images via an SVD-PCA-based method; after the noise reduction operation, the DWI images are obtained and subjected to non-linear fitting operation, and estimated parameters of noncoherent motion in voxel can be obtained; the parameters comprise true diffusion coefficients, false diffusion coefficients and perfusion scores. According to the diffusion-weighted imaging method, after singular values of a vector composite matrix are filtered, noise components of the DWI images can be effectively removed; a signal to noise ratio can be improved, and therefore reliability of the estimated parameters of the noncoherent motion in the voxel can be improved.