41 results about "Phased array coil" patented technology

Three MRI acquisitions are performed to acquire data from which separate water and fat images may be reconstructed using a three-point Dixon technique. The NMR data is acquired with a phased array coil having four separate coil elements. Low resolution images are reconstructed from the acquired NMR data sets and used to calculate phase corrections which are used to correct reconstructed high resolution images. The corrected high resolution images are processed using the Dixon technique to produce fat and water images for each coil element which are combined into a single fat and a single water image.

A magnetic resonance imaging apparatus includes a sensitivity map data generating unit and a sensitivity corrected image data generating unit. The sensitivity map data generating unit generates reference image data based on data for generating sensitivity map data of a phased array coil and generates the sensitivity map data by using reference image data after correction processing obtained by applying the correction processing to improve a uniformity with the reference image data based on the reference image data and phased array coil data for generating the sensitivity map data. The sensitivity corrected image data generating unit acquires image data for imaging with the phased array coil and performs sensitivity correction of the image data using the sensitivity map data.

The inventors have established design principles for phased-array MRI coils from the considerations of the target region of the anatomy being evaluated and physical anatomy of the patients. Accordingly, the inventors have demonstrated shape-optimized phased array coils with dense packing of 32 channels for posterior-head imaging exhibiting the SNR gains required to realize not only sub-millimeter fMRI BOLD imaging but also allowing single-shot Gradient Echo-EPI imaging to be performed upon general 3 T MRI instruments. At the same time the design techniques address ergonomic considerations of the patient and designing shape-optimized phased-array MRI coils and patient supports that account for variations within the human population arising from factors such as race, gender, etc.

Based on a theory that a reconstructed image in magnetic resonance is modulated by a phased array coil unit sensitivity, the invention provides a regularization correction method of a magnetic resonance phase array coil image uniformity. According to the method of the invention, a general coil with the uniform sensitivity in the superconductive magnetic resonance and each phased array imaging coil channel are used to carry out pre-scan so as to obtain the coil sensitivity. Through introducing a regular function, noise of the reconstructed image can be inhibited. Simultaneously, in the superconductive resonance, the general-coil pre-scan image is taken as a reference image in a regularization function so that the good uniformity can be obtained. A calculating speed is very fast. The method has little influence on image reconstruction time.

The invention discloses an integrated coil, special for non-human primates, in a magnetic resonance imaging system. According to the technical scheme, the integrated coil comprises a coil shell, a radio-frequency emission unit, a signal receiving unit, a pre-amplification unit, a cable connector connected and communicated with the magnetic resonance imaging system and a three-dimensional positioning device matched with the coil. The integrated coil has the advantages that the radio-frequency emission unit uses a birdcage type coil, provides a stable and even radio-frequency field, and is high in emission efficiency and low in SAR value; the signal receiving unit uses an eight-channel phased array coil, fits the head of a primate, detects deep tissue signals, acquires images with high signal-to-noise ratio and high spatial resolution and is cooperated with the parallel imaging technology to increase magnetic resonance imaging speed, shorten echo time and evidently improve EPI image signal-to-noise ratio and geometric distortion; the head fixing component of the three-dimensional positioning device is fixed with the coil through ear rods on two sides, and the head of the primate can be stably fixed in the optimal imaging area of the coil for magnetic resonance imaging.

A magnetic resonance imaging apparatus includes a phased array coil including a plurality of local coils, a pre-scanning unit which pre-scans, before image scanning, an area including at least part of an image scanning area, a determination unit which determines whether each of the local coils is abnormal, based on signals output from the local coils during pre-scanning, and an information supply unit which supplies a user with information indicating an abnormal local coil, if the determination unit determines that the local coils include the abnormal local coil.

For a purpose of improving homogeneity of an image obtained in a self-calibration by a parallel imaging method generally referred to as SENSE (SENSitivity Encoding), sensitivity factors S_n(p) are calculated using an additive image A_b=Σ|C_n| of complex images C_n obtained by conducting a calibration scan of an entire FOV for phased array coils Coil_n (n=1–N, N≧2) (Steps V2, V3). Moreover, sensitivity maps S_n are generated by conducting curve fitting by the method of least squares weighted by the square of a pixel value A_b(p) of the absolute value additive image A_b (Step V4).

A coil for magnetic resonance imaging operates in a transmit mode with multiple loops locked together in a phase relationship like a birdcage coil to provide a uniform transmission field, but in a receive mode like a phased array coil, each coil operating independently to produce a separate signal for reception by the MRI machine. Phasing of the coil during transmit mode is provided by a ring resonator controllably coupled to the loops. Controllable coupling is provided by a series of current limiting elements interposed between the resonant ring and the loops of the coil.

The present invention is directed to a system and method of resealing spectroscopic data acquired with phased-array or surface coils to absolute “local” units and, hence, preserves the industry-desirable quantitative approach to single voxel MRS. An MRS signal is acquired from water using a body coil and is used as a reference signal to scale MR spectroscopic data acquired with a plurality of RF receive coils, i.e. phased-array or surface coils. In the resealing process, the amplitude of water in the MRS data will be set to match the amplitude of the water reference signal.

The invention provides a brain function magnetic resonance imaging method and system. The method comprises the following steps: obtaining a dynamic data image corresponding to each phased array coil based on multi-channel parallelism and sparse sampling; obtaining a standard image of each phased array coil at an obtaining moment of each dynamic data image according to a first reference image; obtaining a primary function of a high-order generalized-grade model according to the standard image; restraining a grade coefficient of the high-order generalized-grade model by using L2 norms; estimating the grade coefficient based on the dynamic data image and the primary function; reconstructing a middle image corresponding to each time point of each channel based on the high-order generalized-grade model according to an estimated value of the grade coefficient and the standard image; reconstructing the middle image based on a sensitivity matrix of each phased array coil to obtain a reconstructed brain function magnetic resonance image. According to the brain function magnetic resonance imaging method and system, image geometric distortion and Nyquist sampling artifact problems of an imaging technology in the prior art are solved.

A phased array coil for a Magnetic Resonance Imaging (MRI) system is provided that includes a first coil and a second coil adjacent the first coil. The first and second coils are configured in a shifted arrangement from a center of examination of the MRI system.

A phased array coil for a Magnetic Resonance Imaging (MRI) system is provided that includes a first coil, a second coil adjacent the first coil, and a third coil adjacent the second coil. The first, second and third coils are configured in a parallel arrangement in a left-right direction of the MRI system.

The invention provides a novel MRI body phased array coil. The novel MRI body phased array coil comprises a receiving coil array and a negative-permeability metamaterial plate, the negative-permeability metamaterial plate is embedded in the receiving coil array, and is as big as the receiving coil array, the negative-permeability metamaterial plate comprises a substrate and a plurality of artificial microstructures, and the artificial microstructures are periodically arrayed on the substrate. The specially designed negative-permeability metamaterial plate can enhance the capability of the MRI body phased array coil in feeding back the magnetic signals of MRI equipment, and thereby the imaging quality of the MRI body phased array coil is increased.

The invention discloses a multi-channel three-dimensional magnetic resonance imaging method based on the 1H-19F-31P nucleus. The method comprises the steps of scanning a part to be imaged by using a multi-channel phased-array coil and a magnetic resonance pulse sequence 1H/19F/31PPANSY-COSY-3D fbSSFP, and obtaining a plurality of phased-array coil images which are a 31P nucleus image, a 1H nucleus image and a 19F nucleus image respectively; and conducting registration and image fusion processing for the plurality of phased-array coil images and then obtaining a nuclear magnetic resonance image capable of providing tumor molecule information and metabolic information. The invention not only has a great practical significance in the early diagnosis of tumor, the improvement in the quality of life of patients, the improvement in the cure rate of tumor and the like, but also has a great strategic significance for our country to get rid of the shackles of foreign medical technology, break through the monopoly of foreign medical technology, and to occupy a world leading position in medical imaging, oncology and so forth.

The invention discloses a multichannel three-dimensional nuclear magnetic resonance imaging method based on the 1H-19F-23Na atomic nucleus. A to-be-imaged part is scanned by using a multi-channel phased array coil and a magnetic resonance pulse sequence 1H/23Na PANSY-COSY, <1>H/<19>F PANSY-COSY, 23Na-23NaCOSY, or 1H/19F/23Na PANSY-COSY, thereby obtaining a plurality of phased array coil images including a 23Na atomic nucleus image, a 1H atomic nucleus image, and a 19F atomic nucleus image; and registering and image fusion processing are carried out on the multiple phased array coil images to obtain a nuclear magnetic resonance image capable of providing tumour molecule information and metabolism information. According to the invention, the method not only has the great practical significance in early-stage diagnosis of a tumour, patient survival quality improvement, and tumour recovery rate enhancement but also has the important strategic significance in eliminating foreign medical technical restriction n, breaking the foreign medical technical monopoly, and taking the leading position in the medical iconography and oncology in the world.

The invention discloses a phased array coil magnetic resonance image non-uniformity correction method based on projection estimation, and the method comprises the steps: obtaining a binary mask image through a threshold method, obtaining an ROI (Region of Interest) image, carrying out the projection of the ROI image, carrying out the fitting of a projection curve through a non-linear fitting method, reconstructing the fitted curve by adopting a Radon inverse transformation method to obtain a bias field estimation image, processing the mask and the bias field estimation image based on a low-pass filtering method, and fusing the original magnetic resonance image, the mask image and the bias field estimation image by utilizing a designed image fusion algorithm to obtain a non-uniformity corrected image. According to the method, the problem of non-uniform image gray caused by non-uniform magnetic field of the radio frequency coil and spatial difference of sensitivity of the phased array coil in a conventional magnetic resonance system is effectively solved, and the magnetic resonance image is corrected by using the method; the result shows that the corrected image greatly improves the uniformity of the image while guaranteeing the signal-to-noise ratio, and the method has a very high clinical application value.

In order to provide a phased-array coil having a highly homogeneous sensitivity region, an opposing coil set 10 composed of a pair of gutter-shaped coils 10a and 10b whose concave surfaces face each other, an opposing coil set 20 composed of a pair of gutter-shaped coils 20a and 20b whose concave surfaces face each other, an opposing coil set 30 composed of a pair of gutter-shaped coils 30a and 30b whose concave surfaces face each other, and an opposing coil set 40 composed of a pair of gutter-shaped coils 40a and 40b whose concave surfaces face each other are disposed around the center axis J of an imaginary cylinder at an angular spacing of 45 DEG , with each coil overlapping the adjacent ones by about 10% of the coil surface area, to be assembled into a cylindrical shape as a whole.

The invention discloses an eight-channel MR-EPT phased array radio frequency coil input radio frequency signal program control system, and the system comprises an eight-channel digital power divider, an eight-bit digital phase shifter, a T/R switch, a master controller, an eight-channel phased array radio frequency coil and an RS485 bus. The eight-channel phased array coil is applied to an MR-EPT system, the amplitude, the phase and the signal transmission direction of radio frequency signals generated by the radio frequency generation unit are modulated, so that the radio frequency signals of all channels in the eight-channel phased array coil have different power amplitudes and relative phases, and the reconstruction precision of MR-EPT is improved. According to the system, radio frequency signal power distribution and phase adjustment parameters are set through the main controller, a control instruction is sent to the control module through the RS485 bus, control over the output channel of the power divider, the phase shift degree of the phase shifter and the working state of the T/R switch is achieved, and meanwhile feedback signals from the onboard controller can be received to be used for verification of control. The adjusting method is flexible and convenient, and the application range is wide during specific application.