Patent application number | Description | Published |
20080204019 | HIGH FIELD MAGNETIC RESONANCE IMAGING APPARATUS AND METHOD FOR OBTAINING HIGH SIGNAL-TO-NOISE BY ITS RECEIVING COIL - In a high field magnetic resonance imaging apparatus and a method for obtaining signals having a high signal-to-noise ratio with the receiving coil thereof, the apparatus has at least a basic magnet and a receiving coil, the basic magnet generating a basic magnetic field, and the receiving coil being disposed within the basic magnetic field and forming an accommodating cavity. The accommodating cavity of the receiving coil is perpendicular to the direction of the basic magnetic field and is positioned in the field of view of the apparatus. The receiving coil is a loop type coil. The apparatus can further have a bracket for fixing the receiving coil. In the method, a receiving coil is used to receive signals in a magnetic field, wherein the receiving coil is perpendicular to the direction of the magnetic field. By using the apparatus and the corresponding method since the receiving coil can have a loop type design, the signal-to-noise ratio is increased. Moreover, the receiving coil can be disposed at a position closer to the center of the field of view, so that the imaging quality is improved. | 08-28-2008 |
20080221431 | METHOD AND APPARATUS FOR TRANSFORMING THE COORDINATE SYSTEM OF MRI-GUIDED MEDICAL EQUIPMENT TO THE COORDINATE SYSTEM OF AN MRI SYSTEM - In a method and an apparatus for transforming the coordinate system of MRI-guided medical equipment to the coordinate system of an MRI system MRI imaging is used to determine the rotational and translational values of the coordinate system of MRI-guided medical equipment relative to the coordinate system of an MRI system, so as to achieve the transformation. A number of fiducial markers are arranged in the MRI-guided medical equipment, and a coil winding is arranged on each fiducial marker for generating signals to determine its position in the coordinate system of the MRI system. The coil windings are serially connected and the serially connected windings are connected to the magnetic resonance system via an interface circuit. | 09-11-2008 |
20080238426 | METHOD AND APPARATUS FOR REDUCING ALIASING ARTIFACTS IN THE IMAGING FOR MR-MONITORED HIFU THERAPY - In a method and magnetic resonance (MR apparatus for reducing aliasing artifacts in the imaging for MR-monitored high intensity focused ultrasound HIFU therapy, a primary coil is used to receive the MR signals, and an additional coil is provided to receive interfering MR signals that form aliasing artifacts in the MR-monitored HIFU therapy imaging. The MR signals received by the primary coil and the interfering MR signals received by the additional coil are concurrently acquired. The interfering MR signals received by the additional coil are removed from the MR signals received by the primary coil. MR images are generated based on the MR signals with the interfering MR signals removed. Aliasing artifacts caused by the interfering MR signals thus are removed from the MR images without reducing the resolution of the scanned body parts in the MR images. In addition, the MR scanning time can be maintained by using a proper phase oversampling technology in the concurrent signal acquisition. | 10-02-2008 |
20080285833 | Method for calculating signal-to-noise ratio in parallel acquisition image reconstruction - The invention discloses a method for calculating the signal-to-noise ratio (SNR) in parallel acquisition image reconstruction, comprising: determining a reconstruction expression for a linear operation of the image reconstruction; determining a weighted coefficient according to the reconstruction expression; calculating the SNR according to the weighted coefficient and the raw data. The SNR not only is relevant to the geometric shape and position of the coils, but also is influenced by the reconstruction method and the sampling mode. The SNR is calculated based on contribution of the raw data at positions in the reading direction from all the phase-coding lines in all acquisition channels. It reflects more precisely the loss of the SNR in the parallel acquisition image reconstruction, especially the changes in the SNR caused by the number of the reference lines combined during the reconstruction. | 11-20-2008 |
20080285834 | Method and apparatus for reconstructing parallel-acquired image - The invention discloses a method and an apparatus for reconstructing a parallel-acquired image, comprising: generating reconstruction data by combining uniformly under-sampled data and low-frequency fully-sampled data in MRI K-space according to a hybrid sampling mode; calculating the sensitivity distribution of a coil according to said low-frequency fully-sampled data; and reconstructing an image according to the reconstruction data, the coil's sensitivity distribution and the hybrid sampling mode. The signal to noise ratio of the reconstructed image is effectively improved by using the reconstruction data combined with the low-frequency fully-sampled data in reconstructing the image since the low-frequency fully-sampled data contains more useful information. | 11-20-2008 |
20090115418 | MAGNETIC RESONANCE COIL COMPOSED OF RELATIVELY MOVABLE CONSTITUENT ELEMENTS - A magnetic resonance coil has an antenna portion for accommodating a body part to be examined, the antenna portion is formed by a number of constituent units connected in series, the positions between various constituent units are relatively movable. By moving the positions between the constituent units, a portion of the area between at least two constituent units overlaps. By increasing or reducing the number of the constituent units, or by adjusting the overlapped area between the constituent units, one pair or a number of pairs of the constituent units are made to overlap completely, so as to achieve the adjustment of the size of the antenna portion to accommodate a body part to be examined, and to make said antenna portion as close as possible to the body part to be examined, so as to obtain a signal with a relatively high signal-to-noise ratio, and to obtain a relatively high imaging quality. | 05-07-2009 |
20090140735 | TEMPERATURE-CONTROLLED MAGNETIC RESONANCE IMAGING METHOD AND APPARATUS - A method for improving the imaging quality of magnetic resonance imaging (MRI) equipment and MRI equipment, include obtaining a corresponding relationship between a deterioration factor of imaging quality and the cumulative energy of gradient pulses applied by successive scanning MRI sequences, then determining a predicted value of a current deterioration factor of imaging quality according to the currently applied cumulative energy of the gradient pulses and said corresponding relationship, adopting a corresponding method to carry out dynamic regulation or compensation using the predicted value of said deterioration factor of imaging quality as a reference, so as to cancel the influence produced by the heating effect of the gradient system to the imaging quality, thereby effectively improving the imaging quality of the MRI equipment. | 06-04-2009 |
20090174408 | RECEIVING DEVICE FOR A MAGNETIC RESONANCE IMAGING SYSTEM - A receiving device for an MRI (magnetic resonance imaging) system has multiple receiving coils. In the same imaging acceleration direction, a junction region is formed between adjacent receiving coils. An additional receiving coil is arranged on the junction region. The additional receiving coil covers at least partially a line of strong phase variation in sensitivity at the boundary of said junction region. This receiving device alleviates the problem of poor sensitivity to MRI signals in the junction region in the imaging acceleration direction, so as to improve the imaging quality in the junction region, and thus improving the overall imaging quality. | 07-09-2009 |
20090174498 | RF SWITCH DEVICE, MAGNETIC RESONANCE IMAGING SYSTEM AND AN RF SIGNAL TRANSMISSION METHOD - A radio frequency (RF) switch device has at least two RF switch units, each RF switch unit having an output terminal and at least two input terminals. The RF switch units select one channel of RF signals from several channels of the RF signals that are supplied as inputs to their input terminals for emission as an output from their output terminals. A magnetic resonance imaging system and an RF signal transmission method employ such an RF switch device. The use of such an RF switch device reduces the number of channels of the RF signals that need to be further transmitted, which in turn reduces the number of the corresponding long RF cable channels and the number of channels of the subsequent devices, thereby preventing waste and reducing the cost of the system. Moreover, if the subsequent devices include a receiver coil channel selector, then the complexity of the receiver coil channel selector will also be reduced as the number of RF signal channels is decreased. | 07-09-2009 |
20090186586 | TRANSMISSION CIRCUIT FOR RADIO FREQUENCY SIGNALS AND METHOD FOR TRANSMITTING RADIO FREQUENCY SIGNALS - A transmission circuit for radio frequency signals has a power mixer and includes a radio frequency input port, a first radio frequency output port, a second radio frequency output port, and a dummy load port. The transmission circuit also has a first switch unit and a second switch unit. The first switch unit is connected to the first radio frequency output port and outputs the radio frequency signals which are emitted from the first radio frequency output port or reflects the radio frequency signals which are emitted from the first radio frequency output port back to the first radio frequency output port. The second switch unit is connected to the second radio frequency output port and outputs the radio frequency signals which are emitted from the second radio frequency output port, or reflects the radio frequency signals which are emitted from the second radio frequency output port back to the second radio frequency output port. The radio frequency signals reflected to the radio frequency input port by the first switch unit and the radio frequency signals reflected to said radio frequency input port by the second switch unit cancel each other. The transmission circuit has reduced complexity and cost. | 07-23-2009 |
20090189744 | IDENTIFICATION CODE CIRCUIT FOR RECEIVING COIL IN MAGNETIC RESONANCE IMAGING SYSTEM - An identification code circuit for a receiving coil in a magnetic resonance imaging system, is embodied in a main coil. The circuit has a fixed resistance for generating the identification code of the main coil. The main coil has a socket for connecting a sub-coil, so that a coil plug of a sub-coil can be plugged into the socket for connecting to the main coil. The identification code circuit also has a regulating resistance and a sub-coil switch corresponding to the socket. The coil plug of the sub-coil is plugged into the socket to close the sub-coil switch, so that the values of the regulating resistance and said fixed resistance are added together to form a combined resistance value. After said main coil has been connected to a magnetic resonance imaging system, an identification code source voltage value across the combined resistance value is the identification code of the combined main coil and sub-coil. A receiving circuit identification code thus can be generated simply and with reduced cost. | 07-30-2009 |
20090190854 | METHOD AND APPARATUS FOR IMPROVING BRIGHTNESS UNIFORMITY IN AN IMAGE - In a method and apparatus for improving the brightness uniformity in an image, signals are acquired using a radio frequency receiving coil, and noise in the acquired signals is normalized so as to produce an image, then the brightness of various pixels in the image is determined according to the sensitivity of the radio frequency receiving coil. The brightness of the image is then made uniform by compensating the brightness of the various pixels in the image. | 07-30-2009 |
20090219026 | MULTI-CHANNEL BIRDCAGE BODY COIL FOR MAGNETIC RESONANCE IMAGING - A birdcage multi-channel body coil has a number of coil units that form a cylindrical shape, and they are connected in succession in the circumferential direction along the side face of the cylinder. The coil units are provided with capacitors with selected capacitance values that eliminate coupling between the coil units. This multi-channel body coil simply and conveniently eliminates the coupling between the coil units. | 09-03-2009 |
20090221906 | WRIST COIL FOR MAGNETIC RESONANCE IMAGING - A wrist coil for magnetic resonance imaging has a tubular coil formed by a number of coil splicing units spliced together in succession, and an annular coil unit that is wound around the surface of the tubular coil. Since the annular coil unit is wound around the surface of the tubular coil, and the current direction in the annular coil unit is perpendicular to the current direction in each of the coil splicing units, when some of the coil splicing units in the tubular coil do not acquire signals due to the fact that their magnetic field direction is parallel to that of the main magnetic field direction, the annular coil unit will carry out signal acquisition. Furthermore, since the magnetic flux of the annular coil unit is relatively large, this ensures a relatively high signal-to-noise ratio in the acquired signals no matter whatever layout position is adopted for the wrist coil, thus reducing equipment costs and eliminating restrictions for clinical applications in the prior art. | 09-03-2009 |
20090243612 | VOLUME COIL FOR MRI SYSTEM - A volume coil for a magnetic resonance imaging system is composed of a number of coil units. In the coil, there are overlapped parts between two adjacent ones of the coil units for eliminating coupling between these two adjacent coil units. Two next-adjacent ones of the coil units, which are separated from each other by one coil unit, are each provided with an inductor, and these two inductors are coupled with each other for eliminating coupling between these two next-adjacent coil units. All coil units are collected on one axial end face of the coil. Two coil units in the coil that are neither adjacent coil units nor next-adjacent coil units are connected with each other on the end face by a capacitance circuit or a inductance circuit for eliminating the coupling between these two coil units that are neither adjacent coil units nor next-adjacent coil units. The coupling among the various coil units is relatively thoroughly eliminated, and the signal-to-noise ratio of the signal received by the coil is increased. | 10-01-2009 |
20090256564 | MAGNETIC RESONANCE RADIO FREQUENCY SYSTEM AND OPERATING METHOD THEREFOR - In a method for processing radio frequency signals of a magnetic resonance imaging system in which the coil portion of the magnetic resonance imaging system includes a body coil and a local coil, radio frequency signals are supplied to the body coil, and these radio frequency signals are coupled to said local coil, and transmitted by said local coil into a region to be examined. A corresponding radio frequency system has a local coil and a body coil, with power coupling between the local coil and the body coil; during the phase for transmitting the radio frequency signals. The body coil serves to couple the radio frequency signals to be transmitted to the local coil, and the local coil serves to transmit the coupled radio frequency signals to a region to be examined. This method and system allow the transmitting function of the local coil to be achieved without having a coil plug on a patient bed to provide a radio frequency signal transmitting channel. | 10-15-2009 |
20090322334 | KNEE COIL FOR MAGNETIC RESONANCE IMAGING - A knee coil for magnetic resonance imaging has a first, a second and a third array of coil units, the first, second and third array of coil units forming a cylindrical shape, and being adjacent to each other in the direction perpendicular to the bottom of the cylindrical shape. Each of the first array of coil units and the third array of coil units is composed of two saddle coil units, and the second array of coil units is composed of six coil units, which are successively adjacent to each other in the direction of circumference of the cylinder side face. With a simple design and at a low cost, this knee coil ensures good capacity of parallel acquisition in all directions in the course of scanning while reducing the number of channels. | 12-31-2009 |
20100280360 | TWO-PART LOCAL SHOULDER COIL, AND MAGNETIC RESONANCE TOMOGRAPHY APPARATUS AND METHOD EMPLOYING SAME - Improved patient comfort is provided by a local coil arrangement designed to support the production of an MRT image of a shoulder, wherein the housing of the local coil arrangement is composed of two separable parts. | 11-04-2010 |
20100283462 | TUBULAR MAGNETIC RESONANCE SURFACE COIL, AND METHOD AND SYSTEM FOR PROCESSING SIGNALS THEREFROM - In a method and system for processing radio frequency signals of a tubular surface coil, the N channels of coil output signals are generated based on M channels of radio frequency signals acquired by M coil units in the tubular surface coil, wherein N is an even number greater than 1 and is less than or equal to M, and the N channels of coil output signals can be divided into N/2 pairs, with the two channels of coil output signals in each of the pairs respectively coming from the coil units located at symmetrical positions of the tubular surface coil. The respective modulus values of the two channels of coil output signals in said each pair of coil output signals are multiplied to obtain N/2 products which are then summed, and the square root of the summed result is computed, so as to generate a lateral cross-sectional image according to the computed result of square root. The signal strength in an imaging area and the uniformity of signal to noise ratio are thereby improved. | 11-11-2010 |
20110025331 | BODY COIL ASSEMBLY AND METHOD FOR GENERATING RADIO-FREQUENCY FIELD USING THE BODY COIL ASSEMBLY - A body coil assembly for a magnetic resonance apparatus has a first coil and a second coil for generating a radio-frequency field in space, and a power control apparatus connected to the first coil and the second coil for controlling the transmitting power of the first coil and the second coil. In a method for generating a radio-frequency field using such a body coil assembly, the transmitting powers of the first coil and the second coil are controlled, to provide unequal transmitting powers to the first coil and the second coil when needed to generate a required radio-frequency field distribution, so as to form a stronger field strength at a certain position, thus improving the signal to noise ratio at that position during the receiving process. | 02-03-2011 |
20130134980 | Receiving Method, Receiving System for Magnetic Resonance Signals, and Magnetic Resonance Imaging System - A method and system for receiving magnetic resonance signals, and a magnetic resonance imaging system are provided. The method includes dividing coil units in a receiving coil array into different coil unit groups. For each of the coil unit groups, correlations are established between carrier frequencies and the signals received by each coil unit in the coil unit group. Low noise amplification is performed, and filtering and frequency mixing is performed on the signals received by all the coil units in the coil unit group according to the correlations to obtain intermediate frequency signals borne on the respectively corresponding carrier frequencies of an identical channel. After performing amplification and filtering on the intermediate frequency signals, the intermediate frequency signals are output to an analog-to-digital conversion unit to perform digital sampling so as to obtain digital domain signals. | 05-30-2013 |
20130221967 | Radio Frequency Coil Device and Magnetic Resonance Imaging Apparatus - An RF coil device and an MM apparatus allowing a connection relationship between input RF channels and output RF channels to be controlled by a smaller number of switch elements are provided. The RF coil device includes multiple coil segments and a multi-selection switch. Input terminals of the multi-selection switch are each connected to a different coil segment. An output terminal of the multi-selection switch leads to an RF output channel. A control terminal of the multi-selection switch is used to receive a control signal so as to select a coil segment for connection to the output terminal. Multiple coil segments connected to the input terminals are not in consecutive positions, and the number of coil segments by which any two of the multiple coil segments are spaced apart is no fewer than the maximum number of coil segments required for one MRI imaging less 1. The MRI apparatus includes the RF coil device. | 08-29-2013 |
20130234714 | Radio Frequency Coil Device and Magnetic Resonance Imaging System - An RF coil device and an MRI system are provided. The RF coil device includes m coil elements, where m is an integer greater than 1. The RF coil device also includes an RF switch control unit including n output terminals and m input terminals connected to the m coil elements, respectively, where n is an integer greater than or equal to 1 and less than m. The RF coil device includes a decoder for outputting a control signal to the RF switch control unit according to a received control command. The RF switch control unit connects each of not more than n input terminals to a different output terminal according to the control signal. | 09-12-2013 |
20140002087 | Method for Simultaneous Transmission of High-Frequency Transmission Signals via a Common High-Frequency Line | 01-02-2014 |
20140058250 | Shoulder Coil and Transmitting Coil for Magnetic Resonance System - A shoulder coil for a magnetic resonance system includes a receiving part. The shoulder coil also includes a transmitting part used for coupling a radio-frequency magnetic field of a body coil of the magnetic resonance system. | 02-27-2014 |
20140117990 | Body Coil for Magnetic Resonance Imaging - A body coil includes a first end ring and a second end ring provided at two ends thereof. The first end ring and the second end ring are connected to each other with a plurality of legs. The first end ring or the second end ring has a structure with the current flow width in a direction parallel to the axis thereof being greater than that in a direction perpendicular to the axis thereof. Since the effective action width of the current is increased in the axial direction and the centralized flow of the current in the end ring is reduced, the local specific absorption rate of radio frequency induced by the magnetic field is therefore reduced. | 05-01-2014 |