摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.