摘要:
To provide a technique for sufficiently eliminating magnetic coupling between RF coils and improving image quality when a multi-element multi-tuned RF coil is used as a receive RF coil for an MRI device. In the invention, each of RF coils which constitute a multi-element multi-tuned RF coil which is used as a receive RF coil for an MRI device is provided with an inter-coil magnetic coupling prevention circuit which resonates at each frequency to which each RF coil is tuned and provides a high impedance. The inter-coil magnetic coupling prevention circuit adjusts an inductor and a capacitor so that both of a circuit on the side of a pre-amplifier viewed from both ends of a signal reception circuit and a circuit on the side of the signal reception circuit viewed from both ends of a serial resonance circuit connected to the pre-amplifier resonate at a plurality of frequencies to which the respective RF coils are tuned.
摘要:
To provide a technique for sufficiently eliminating magnetic coupling between RF coils and improving image quality when a multi-element multi-tuned RF coil is used as a receive RF coil for an MRI device. In the invention, each of RF coils which constitute a multi-element multi-tuned RF coil which is used as a receive RF coil for an MRI device is provided with an inter-coil magnetic coupling prevention circuit which resonates at each frequency to which each RF coil is tuned and provides a high impedance. The inter-coil magnetic coupling prevention circuit adjusts an inductor and a capacitor so that both of a circuit on the side of a pre-amplifier viewed from both ends of a signal reception circuit and a circuit on the side of the signal reception circuit viewed from both ends of a serial resonance circuit connected to the pre-amplifier resonate at a plurality of frequencies to which the respective RF coils are tuned.
摘要:
There is a provided a technology of receiving a magnetic resonance signal highly sensitively and with a uniform sensitivity distribution in an RF coil of an MRI device which is an RF coil including a switch circuit of switching a circuit configuration. The RF coil of the MRI device of the present invention includes a switch circuit of switching a circuit configuration. Also, the switch circuit switches the circuit configuration by being driven by a control signal received by wireless. For that purpose, the switch circuit includes an antenna of receiving the control signal and a conversion circuit of converting an alternating current voltage received into a direct current voltage.
摘要:
Provided is an RF coil which can highly efficiently and uniformly irradiate a RF magnetic field having two or more magnetic resonance frequencies close to each other, and receive magnetic resonance signals of two or more magnetic resonance frequencies close to each other with high sensitivity and uniform sensitivity profile in an MRI apparatus. Two or more frequencies to which the coil is tuned are adjusted so as to be between resonance frequencies of series resonant circuits constituting the RF coil.
摘要:
An RF coil having at least three different resonance frequencies, wherein one of the resonance frequencies is adjusted to be a frequency fA of a magnetic resonance signal generated by a test subject, and the coil is adjusted so that ratio of difference between the frequency fA and a first frequency fB lower than fA and nearest to fA among the resonance frequencies (fA−fB), and difference between the frequency fA and a second resonance frequency fC higher than fA and nearest to the frequency fA among the resonance frequencies(fC−fA), should be from 0.5 to 2.0. There is provided a technique for receiving magnetic resonance signals always with high detection efficiency by an RF coil of an MRI apparatus even if significant loss is caused in the RF coil, or test subject is changed.
摘要:
An RF coil having at least three different resonance frequencies, wherein one of the resonance frequencies is adjusted to be a frequency fA of a magnetic resonance signal generated by a test subject, and the coil is adjusted so that ratio of difference between the frequency fA and a first frequency fB lower than fA and nearest to fA among the resonance frequencies (fA−fB), and difference between the frequency fA and a second resonance frequency fC higher than fA and nearest to the frequency fA among the resonance frequencies (fC−fA), should be from 0.5 to 2.0. There is provided a technique for receiving magnetic resonance signals always with high detection efficiency by an RF coil of an MRI apparatus even if significant loss is caused in the RF coil, or test subject is changed.
摘要:
The present invention provides a technique for maintaining a function for effectively blocking common mode noise with a simple configuration, even in the case where unbalance occurs in characteristic impedance of a coaxial cable in an MRI apparatus, and improving the performance of an RF coil. In a circuit where a balun is established by parallel connection with the coaxial cable, multiple serial resonance circuits having different resonance frequencies are connected in parallel. A value of each constitutional element of each of the serial resonance circuits is adjusted in such a manner that the frequency for blocking the common mode noise of the entire balun falls into a range between the resonance frequencies of these serial resonance circuits.
摘要:
The present invention provides a technique for maintaining a function for effectively blocking common mode noise with a simple configuration, even in the case where unbalance occurs in characteristic impedance of a coaxial cable in an MRI apparatus, and improving the performance of an RF coil. In a circuit where a balun is established by parallel connection with the coaxial cable, multiple serial resonance circuits having different resonance frequencies are connected in parallel. A value of each constitutional element of each of the serial resonance circuits is adjusted in such a manner that the frequency for blocking the common mode noise of the entire balun falls into a range between the resonance frequencies of these serial resonance circuits.
摘要:
Provided is an RF coil which can highly efficiently and uniformly irradiate a RF magnetic field having two or more magnetic resonance frequencies close to each other, and receive magnetic resonance signals of two or more magnetic resonance frequencies close to each other with high sensitivity and uniform sensitivity profile in an MRI apparatus. Two or more frequencies to which the coil is tuned are adjusted so as to be between resonance frequencies of series resonant circuits constituting the RF coil.
摘要:
It is intended to provide a Magnetic Resonance Imaging (MRI) phantom for 1H/19F signal detection that permits the stable and uniform dispersion of a vesicle and to accomplish the adjustment of a measurement parameter for a 1H/19F signal and performance confirmation by use of the phantom. The present invention provides an MRI phantom having a gel comprising a vesicle comprising at least one of a perfluorocarbon and a superparamagnetic iron oxide particle and an MRI system having the phantom.