26 results about "Magnetic resonance elastography" patented technology

Techniques are disclosed for preparing an MR elastography of a liver, which includes creating a photographic recording of an examination object, determining a position of the liver on the basis of the photographic recording, providing an information item regarding a target position of an oscillation generator on the basis of the position of the liver, arranging the oscillation generator on the examination object dependent upon the information regarding the target position, introducing the examination object with the oscillation generator into a patient receiving region of a magnetic resonance device, capturing overview MR image data from the examination object, and selecting an examination region for transverse slices covering at least one subregion of the liver for a recording of MRE image data on the basis of the overview MR image data.

The invention relates to the technical field of magnetic resonance imaging, in particular to a coil assembly and device for small animal magnetic resonance elastography. The coil assembly comprises: a first chamber for accommodating a small animal as an examined object; a radio frequency coil disposed on the outer peripheral side of the first chamber; and a first hole communicating with the first chamber and facing the small animal for receiving a vibrating member, where the vibrating member is inserted into the first chamber via the first hole and contacts the small animal in a facing direction of the first hole.

A driver for transperineal magnetic resonance elastography provides a body harness stabilizing a mechanical actuator against a body reference point to provide improved imaging. The driver may employ a polymer bellows for mechanical simplicity and low cost.

The present invention provides a method, system, medium, and device for constructing a brain network based on mechanical parameters, comprising: step S1: acquiring a brain structural image and a mechanical parameter distribution image using magnetic resonance elastography, registering the brain structural image and the mechanical parameter distribution image, segmenting them using a standard spatial atlas, and extracting the mechanical modulus value of each pixel in each brain region; step S2: calculating the probability distribution function of each brain region and estimating the similarity of the probability distribution functions of each brain region using KL divergence; and step S3: using the calculated KL divergence values ​​as connections between different brain regions, constructing a mechanical network and performing graph theory analysis, comparing graph theory indicators between healthy individuals and patients with neurodegenerative diseases. The present invention can improve the efficiency of early diagnosis of neurodegenerative diseases.

The present application relates to the field of magnetic resonance imaging technology, and more particularly to a coil assembly and apparatus for magnetic resonance elastography of small animals. The coil assembly comprises: a first chamber for accommodating a small animal as an examination subject; a radio frequency coil disposed on the outer periphery of the first chamber; and a first hole connected to the first chamber and facing the small animal, for receiving a vibrating member, wherein the vibrating member is inserted into the first chamber through the first hole and contacts the small animal along the direction of the first hole.

The invention relates to a method for preparing an MR elastography of a liver according to the following method steps: - Creating a photographic image of an object under investigation, - Determination of the position of the liver based on the photograph, - Providing information regarding a target position of a vibration generator based on the position of the liver, - Positioning the vibration generator on the object under investigation depending on the information regarding the target position, - Introducing the examination object with the vibration generator into a patient receiving area of a magnetic resonance device, - Acquisition of overview MR image data of the examination subject, - Selection of an examination region for transverse slices covering at least a partial area of the liver for acquisition of MRE image data based on the overview MR image data.

In a method for performing Magnetic Resonance Elastography (MRE) more efficiently may include providing a periodical vibration signal for exciting mechanical vibrations within an object to be examined with a vibration period, sampling the vibration signal with a sampling period corresponding to a natural number including zero of vibration periods plus a fixed time delay, and performing three motion encoding gradients for magnetic resonance acquisition in each sampling period. The fixed time delay multiplied with a sampling number may be equal to the vibration period. The sampling number may be a natural number greater than two.

The present invention concerns the assessment of mechanical tissue properties in vivo. For this, magnetic resonance elastography (MRE) is often used but suffers from a poor adaptability of the reconstruction process of the mechanical tissue properties based on the images taken by MRE. There is therefore a need for a method for determining mechanical parameters of a tissue of a subject, which is adapted to his / her specificities. The present invention provides with a novel reconstruction process fulfilling this need by a smart use of resampling. This improvement is also advantageous to diagnose chronic diseases or provide biomarkers / therapeutical targets relative to chronic diseases by using these better assessed mechanical tissue properties provided by the novel reconstruction process.

The disclosure relates to an elastography apparatus designed to support magnetic resonance elastography, including an oscillation generator, a fixation apparatus designed to fix the oscillation generator to an object under examination, a pressure sensor designed to detect a contact pressure acting between the oscillation generator and the object under examination, and an output unit designed to output the detected contact pressure.

The invention discloses an internal reference tissue correction method and system for virtual magnetic resonance elastography of acute pancreatitis, relates to the technical field of medical image processing and quantitative evaluation, and discloses the internal reference tissue correction method and system for virtual magnetic resonance elastography of acute pancreatitis. According to the method, the problems of numerical discreteness and deviation in virtual magnetic resonance elastography of acute pancreatitis are solved by automatically identifying internal reference tissues, calculating correction coefficients, correcting elasticity values in a partitioned manner and generating a structured report, and the repeatability of pancreatic hardness measurement and cross-equipment and cross-time-point data comparability can be improved.

The present invention provides an excitation device, system and method for head magnetic resonance elastography driven by the neck. The excitation device includes an electromagnetic drive structure. The electromagnetic drive structure acts on the human neck to achieve vibration of the human neck, and the vibration is transmitted to the brain tissue through the human tissue connecting the human neck and the head. The present invention greatly simplifies the structural complexity of the head magnetic resonance elastography excitation device while ensuring the vibration effect. By adopting a neck drive structure, the drive mechanism is separated from the head coil, and no additional fixing and positioning mechanism is required, thus solving the problem of wide applicability for different head coil structures.

The disclosure is based on a magnetic resonance system comprising a magnetic resonance apparatus with a scanner unit having a main magnet, a gradient coil unit, and a radio-frequency coil unit; a patient receiving region at least partially surrounded by the scanner unit, and an elastography apparatus embodied to excite regions of interest of a patient during a magnetic resonance elastography examination on the patient, comprising a vibration unit, a magnetic resonance-compatible drive unit, and a transmission unit for transmitting a drive torque generated by the magnetic resonance-compatible drive unit to the vibration unit. The magnetic resonance-compatible drive unit has a magnetic resonance-compatible motor.

The invention provides an electromagnetically-driven abdomen magnetic resonance elastography excitation device. The electromagnetically-driven abdomen magnetic resonance elastography excitation device comprises a coil, a vibrating rod, a vibrating plate, a connecting rod and a supporting plate. The two ends of the vibration rod are fixedly connected with the coil and the vibration plate respectively, the coil is driven by current and a magnetic field to generate vibration in the vertical direction, and the vibration plate is driven by the vibration rod to generate vibration in the vertical direction; the vibration plate and the supporting plate are fixedly connected through the connecting rod to form a clamp shape, the vibration plate and the supporting plate are matched to clamp the abdominal cavity of the human body, the connecting rod is movably installed on the supporting plate, and the vibration plate can be close to or away from the supporting plate by moving the connecting rod. The electromagnetic drive coil vibrates, the vibration rod drives the vibration plate to vibrate, the vibration frequency is accurate, and the vibration amplitude can be continuously adjusted; the vibration plate and the supporting plate are matched with each other, such as a clamp, to clamp the abdominal cavity of a human body, so that the contact area with the abdominal cavity is enlarged, close fit with the human body is ensured, and the vibration efficiency is improved.

The application relates to a magnetic resonance frequency calibration method and a magnetic resonance device. The method is applied to a magnetic resonance device, and the method comprises the following steps: applying an imaging sequence and a calibration sequence to an imaging object; the calibration sequence is located between two adjacent imaging sequences; the imaging sequence is a functional magnetic resonance elastography sequence; a first echo signal and a second echo signal corresponding to the current calibration sequence are acquired, and a frequency drift amount is determined according to the first echo signal and the second echo signal; the reference frequency of the magnetic resonance device is calibrated according to the frequency drift amount, and an imaging sequence adjacent to the current calibration sequence is applied to the imaging object based on the calibrated reference frequency. The magnetic resonance frequency calibration method provided by the application can realize calibration of the reference frequency of a magnetic resonance device with a short repetition time.

A method for generating images indicative of mechanical properties of a subject tissue which is divided into a plurality of slabs each having a plurality of slices, includes performing an MRE scan on the subject tissue with an MRI system. MRE data related to the subject tissue is obtained and processed via a control device. A controller performs an MRE magnetization prepared imaging sequence comprising elastographic magnetization prepared imaging with k-space encoding in accordance with a plurality of scan parameters. The sequence includes: (a) performing a magnetization preparation block, (b) applying magnetic field gradients to spoil residual signal and minimize image artifacts, (c) performing an imaging readout block, with the plurality of scan parameters including sampling each k xy plane using a series of interleaved shots, (d) acquiring k-space data based on steps (a)-(c), and (e) applying an image reconstruction algorithm, thereby generating the images.

An elastography apparatus is described that is designed to assist in magnetic resonance elastography of the head of an examination object. The elastography apparatus comprises a first support element which is designed to be positioned within a radiofrequency receiving coil unit and a vibration generator which is designed to generate mechanical waves. The first support element has a first recess for receiving the vibration generator, the first support element has a second recess for receiving the head, and the first recess is so shaped as to at least partially enclose the vibration generator in a custom-fit manner and the vibration generator is arranged at least partially within the first recess.

A driver for transperineal magnetic resonance elastography provides a body harness stabilizing a mechanical actuator against a body reference point to provide improved imaging. The driver may employ a polymer bellows for mechanical simplicity and low cost.

Disclosed are systems and method for automated magnetic resonance elastography (MRE) quality control and stiffness measurements. The exemplary systems and methods described herein utilize deep learning (DL) to reduce inter-observer variability, improve processing time and workflow constraints, and assist operators with troubleshooting based on artifact sources.

The present invention provides an iterative magnetic resonance elastography displacement extraction method and system with dual data fidelity terms, comprising: Step S1: establishing a phase image model and using cross-phase subtraction to remove background phase; Step S2: designing a data fidelity term to perform principal component extraction equivalent to a Fourier transform; Step S3: designing a gradient data fidelity term to perform phase unwrapping; and Step S4: selecting hyperparameters and performing an iterative solution. By designing new data fidelity terms and gradient data fidelity terms, the present invention simultaneously performs phase unwrapping and Fourier transform in magnetic resonance elastography, addressing the difficulty of extracting displacement from complex, noisy data in magnetic resonance elastography.

This invention discloses a gold nanoparticle enhancer for magnetic resonance elastography, its preparation method, and its application, belonging to the field of medical imaging technology. The preparation method includes dissolving trisodium citrate in deionized water to obtain solution A, then adding chloroauric acid solution to generate solution B. When the temperature of solution B drops to 90°C, an equal amount of chloroauric acid solution is added to form solution C and stirred. An equal amount of chloroauric acid solution is added again and stirred to form solution D. After the reaction is complete, ultrafiltration, centrifugation, and washing are performed to obtain the gold nanoparticle enhancer. This invention achieves the controllable synthesis of the gold nanoparticle enhancer. The preparation method is simple, easy to operate, and has good reproducibility. The obtained gold nanoparticle enhancer has uniform particle size, good dispersibility, and excellent stability, making it easy to scale up production. More importantly, the gold nanoparticle enhancer prepared by this invention has excellent low toxicity and good biocompatibility.

This invention relates to a method and medium for quantifying biomechanical heterogeneity and predicting prognosis in hepatocellular carcinoma (HCC) based on a multi-scale mechanical interaction network. The method includes: retrieving the shear modulus and loss angle parameter maps of the tumor based on multi-frequency magnetic resonance elastography data; dividing the tumor into multiple biomechanical regions using mechanical gradient-driven adaptive clustering; constructing an intratumoral mechanical interaction network and extracting its topological features; constructing a multi-organ mechanical coupling model of the tumor, liver, and spleen, and calculating the cross-organ stress transfer efficiency as a coupling feature; fusing intratumoral network features and cross-organ coupling features to form a multi-scale biomechanical phenotypic vector, and inputting it into a machine learning model in conjunction with clinical features to achieve individualized and accurate prediction of postoperative recurrence risk in HCC patients. Compared with existing technologies, this invention provides a novel systemic biomechanical perspective for prognostic assessment by quantifying the intratumoral mechanical heterogeneity and its mechanical interaction with host organs.

The invention relates to an elastography device designed to support magnetic resonance elastography of the head of an examination object. The invention relates to an elastography device comprising a first support element designed to be positioned within a radio frequency receiving coil unit and a vibration generator designed to generate mechanical waves, the first support element having a first recess for receiving the vibration generator, the first support element has a second recess for receiving the head, and the first recess is shaped in such a way that the first recess surrounds the vibration generator at least partially in a precisely matched manner and the vibration generator is arranged at least partially in the first recess.

The application discloses a method and system for correcting internal reference tissues in virtual magnetic resonance elastography of acute pancreatitis, and relates to the technical field of medical image processing and quantitative evaluation. The method and system for correcting internal reference tissues in virtual magnetic resonance elastography of acute pancreatitis are disclosed, which automatically identifies internal reference tissues, calculates correction coefficients, corrects elastic values in different regions, and generates a structured report. The method and system solve the problems of numerical dispersion and deviation in virtual magnetic resonance elastography of acute pancreatitis, and can improve the repeatability of pancreas hardness measurement and the data comparability between different devices and different time points.

This invention provides a three-dimensional fast magnetic resonance elastography acquisition and reconstruction method and system, comprising: Step S1: generating vibration using an external vibrator and transmitting it into human tissue to generate fluctuations within the tissue; Step S2: having the magnetic resonance scanner receive a synchronization signal and applying an image acquisition sequence to record the fluctuation information of the human tissue; Step S3: acquiring the raw data and using a fast reconstruction algorithm to obtain an accurate fluctuation image of the human tissue. This invention uses a multi-block alternating acquisition method, which can maintain the signal-to-noise ratio of the image even with short transmission cycles (TRs), thereby increasing the number of samples within the same vibration cycle and improving acquisition efficiency. This invention uses three-dimensional excitation and acquisition, increasing the intensity of the acquired signal itself, thus overcoming the shortcomings of previous methods.

A magnetic resonance elastography apparatus, which may include a magnetic resonance apparatus and an elastography apparatus, is described. The magnetic resonance apparatus comprises a scanner unit, a patient receiving region surrounded at least partially by the scanner unit, and a patient couch, which is embodied to introduce a patient into the patient receiving region. The elastography apparatus comprises a drive unit, a vibration applicator which is arranged for an examination on the patient, and a force transmission unit, which is embodied to transmit a drive moment from the drive unit to the vibration applicator. The elastography apparatus comprises an EMC-tight shield housing with a cylindrical radiofrequency hollow conductor, and the drive unit is arranged within the radiofrequency hollow conductor.

Techniques are disclosed for preparing an MR elastography of a liver, which includes creating a photographic recording of an examination object, determining a position of the liver on the basis of the photographic recording, providing an information item regarding a target position of an oscillation generator on the basis of the position of the liver, arranging the oscillation generator on the examination object dependent upon the information regarding the target position, introducing the examination object with the oscillation generator into a patient receiving region of a magnetic resonance device, capturing overview MR image data from the examination object, and selecting an examination region for transverse slices covering at least one subregion of the liver for a recording of MRE image data on the basis of the overview MR image data.