A system for acquiring directional information about a geologic formation includes at least one directionally sensitive nuclear magnetic resonance (NMR) assembly disposed at a borehole string including the downhole component. The at least one NMR assembly includes at least one magnet configured to generate a static magnetic field and at least one coil configured to generate an oscillating magnetic field, the at least one NMR assembly configured to perform an NMR measurement of at least one sector of a formation region. The system also includes a processing device configured to receive NMR measurement data from the at least one NMR assembly. The processing device is configured to analyze the NMR measurement data to estimate a parameter of the sector, determine a direction of the downhole component based on the estimated parameter; and steer the downhole component according to the determined direction.

Some aspects comprise a tuning system configured to tune a radio frequency coil for use with a magnetic resonance imaging system comprising a tuning circuit including at least one tuning element configured to affect a frequency at which the radio frequency coil resonates, and a controller configured to set at least one value for the tuning element to cause the radio frequency coil to resonate at approximately a Larmor frequency of the magnetic resonance imaging system determined by the tuning system. Some aspects include a method of automatically tuning a radio frequency coil comprising determining information indicative of a Larmor frequency of the magnetic resonance imaging system, using a controller to automatically set at least one value of a tuning circuit to cause the radio frequency coil to resonate at approximately the Larmor frequency based on the determined information.

A method of designing a coil array for use in a magnetic resonance imaging (MRI) system based on eigenmode analysis of a scattering matrix associated with the coil array is provided. The method includes determining a normalized reflected power generated by coils in the coil array in response to excitation thereof via at least one excitation signal, and adjusting one or more parameters of at least one of the coils so as to minimize the normalized reflected power.

The disclosure relates to a hybrid orthogonal signal generator, a coil transmission front-end device, an RF coil system, and an MRI system. The hybrid orthogonal signal generator has an input end for receiving an RF signal, generates a hybrid orthogonal excitation signal on the basis of the RF signal, and provides the hybrid orthogonal excitation signal by means of an output end of the hybrid orthogonal signal generator, and comprises: a first conductor, arranged in a plane and being arc-shaped; and a second conductor having mutual inductance with the first conductor, the second conductor being connected between the input end and output end, wherein the first conductor and second conductor are parallel and arranged as mirror images of each other. The hybrid orthogonal signal generator has a compact size and is suitable for providing hybrid orthogonal excitation signals for an MRI system with a low field strength.

A system and method are provided for operating a magnetic resonance tomograph. A transmitter of the magnetic resonance tomograph transmits a predetermined test pulse with a reduced power. The magnetic resonance tomograph receives the test pulse with the local coil. A controller compares the received test pulse with a predetermined pulse response and emits a warning signal when the received test signal differs from the predetermined pulse response.

Embodiments of the present invention provide an antenna arrangement including a magnetic antenna and a tuning element. The magnetic antenna includes a loop interrupted one or several times and a tuning element for tuning the magnetic antenna. The tuning element is configured to provide a tuning signal (e.g., control signal) for tuning the magnetic antenna, and to control the tuning element with the tuning signal to tune the magnetic antenna.

A method for performing an NMR measurement on a sample contained in a sample tube by using an NMR spectrometer includes: a) feeding a first measuring sample tube in a guiding direction to a pre-measuring area being located, in the guiding direction, before a measuring area of the NMR spectrometer, the pre-measuring area being arranged and designed for measuring a sample parameter of a sample contained in the first measuring sample tube to determine or to estimate an NMR parameter; b) feeding the first measuring sample tube in the guiding direction towards the measuring area; c) setting the NMR parameter previously determined or estimated; and d) carrying out an NMR measurement of the sample contained in the first measuring sample tube on the basis of the set NMR parameter.

The invention provides for a magnetic resonance imaging system (100) comprising a main magnet (104) for generating a main magnetic field within an imaging zone (108). The magnetic resonance imaging system further comprises an RF coil (114) for acquiring magnetic resonance data (164) from the imaging zone, wherein the RF coil comprises multiple RF ports (124, 412, 414, 416, 500, 502, 702, 1004, 1006). The RF coil comprises a switch unit (120) for at least one of the multiple RF ports to individually couple or uncouple the at least one of of the multiple RF ports from the RF coil. The magnetic resonance imaging system further comprises a radio-frequency system (125) for supplying radio-frequency power to each of the multiple RF ports and an RF matching detection system (122) for measuring impedance matching data (166) between the radio-frequency system and the RF coil. Execution of the machine executable instructions causes a processor controlling the magnetic resonance imaging system to measure (200, 300, 302, 304) the impedance matching data using the RF matching detection system; determine (202) switch unit control instructions (168) using the impedance matching data, wherein the switch control instructions contain commands that control the at least one of the multiple RF ports to couple or decouple to impedance match the radio-frequency system to the RF coil; and control (204) the switch unit of the at least one of the multiple RF ports with the switch unit control instructions.

A measurement device includes a microwave generator, an electron spin resonance member, and an observation system. The microwave generator is configured to generate a microwave. The microwave is configured for an electron spin quantum operation based on a Rabi oscillation. The microwave generator has a coil configured to emit the microwave and an electrostatic capacitance member electrically connected in parallel to the coil. The microwave is irradiated to the electron spin resonance member. The observation system is configured to measure a physical quantity in a measured field in response to a state of the electron spin resonance member when the electron spin resonance member is irradiated by the microwave. The electrostatic capacitance member is directly connected to the coil or is arranged between the coil and an electric element that is electrically connected to the coil.

A magnetic resonance coil and a magnetic resonance imaging system using the same are provided. The magnetic resonance coil may include an antenna, an amplifier, and a protective circuit. The antenna may be configured to receive a radio frequency (RF) signal emitted from an object. The antenna may not resonate with the RF signal. The amplifier operably coupled to the antenna configured to amplify the RF signal. The protective circuit may be configured to protect the antenna and the amplifier.