A system includes a table and a material detection system. The material detection system includes a transmit chain configured to generate first radio frequency (RF) signals and a transmit probe configured to transmit the first RF signals towards an item through open space. The material detection system also includes a receive probe configured to receive second RF signals from the item through open space, where the second RF signals have one or more characteristics indicative of one or more materials within the item. The material detection system further includes a receive chain configured to process the second RF signals and at least one processing device configured to identify the one or more materials within the item using nuclear quadrupole resonance (NQR) spectrometry based on the processed second RF signals. The transmit and receive probes are positioned in an upper portion of the table.

A coil assembly for MR imaging applications comprises—an electrically conducting RF transmitter coil arrangement (2) for generating an excitation field at an MR operating frequency, the transmitter coil arrangement forming a tubular structure disposed around an imaging volume (4) and having a longitudinal axis (A); —an external RF shield (6) surrounding the transmitter coil arrangement; —at least one electrically conducting RF receiver coil (8; 8a, 8b) disposed within the imaging volume for receiving MR signal from a subject or object disposed therein, the receiver coil being electrically connected, at a connection point (10; 10a, 10b) thereof, to a respective RF receive line (12; 12a, 12b) connectable to a receiver device (14) located outside of the external RF shield. In order to improve the performance of the coil assembly, the respective RF receive line of each receiver coil is oriented substantially perpendicular to the longitudinal axis (A) in a receiver-proximal segment (16; 16a, 16b) between the connection point (10; 10a, 10b) and a neighboring face portion (18; 18a, 18b) of the external RF shield through which the receive line (12; 12a, 12b) is conducted.

The invention relates to a magnetic resonance receive coil including a resonator for use in a magnetic resonance imaging system. The radio frequency receive coil according to the invention comprises a first conducting element of the resonator having a conductive loop wherein the received signal is induced in that loop, configured to form a primary resonant circuit tunable to at least one first resonance frequency and a second conducting element of the resonator configured to form an electric circuit electrically insulated from and reactively coupled to the primary resonant circuit, the electric circuit being adapted to detune the primary resonant circuit to at least one second resonance frequency. The second conducting element of the resonator has a conductive loop with a pair of ends connected to a preamplifier. The radio frequency receive coil further comprises an energy harvesting circuit electrically coupled in parallel over the pair of ends of the second conducting element, wherein the energy harvesting circuit is adapted for being connected to the second conducting element during transmission by a switch. A rechargeable power source is coupled to the energy harvesting circuit, wherein the rechargeable power source is adapted for being charged by the energy harvesting circuit. A switching component is circuited in parallel to the energy harvesting circuit, wherein is adapted to redirect a current as soon as the rechargeable power source is charged to a sufficient voltage. In this way, a magnetic resonance receive coil with a detune circuit and an energy harvesting circuit for energy harvesting is provided without a significant loss of detuning performance.

An example multi-channel magnetic resonance (MR) system is described. The system includes a plurality of radio frequency (RF) coils and a plurality of spectrometer transceiver channels. Each of the channels including a spectrometer coupled a respective set of the RF coils. The spectrometer is configured to transmit RF signals to excite respective RF coils and to receive MR sensor signals from the excited respective RF coils responsive to excitation thereof. The spectrometer is configured to perform MR spectrometry to provide MR measurement data based on the received MR sensor signals for the respective channel. A synchronization module is coupled to the spectrometer of the respective channel. The synchronization module is configured to synchronize the spectrometer of the respective channel with spectrometers in other channels via a communication link.

According to some aspects, a portable magnetic resonance imaging system is provided, comprising a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging. The magnetics system comprises a permanent B.sub.0 magnet configured to produce a B.sub.0 field for the magnetic resonance imaging system, and a plurality of gradient coils configured to, when operated, generate magnetic fields to provide spatial encoding of emitted magnetic resonance signals, a power system comprising one or more power components configured to provide power to the magnetics system to operate the magnetic resonance imaging system to perform image acquisition, and a base that supports the magnetics system and houses the power system, the base comprising at least one conveyance mechanism allowing the portable magnetic resonance imaging system to be transported to different locations. According to some aspects, the base has a maximum horizontal dimension of less than or equal to approximately 50 inches. According to some aspects, the portable magnetic resonance imaging system weighs less than 1,500 pounds. According to some aspects, the portable magnetic resonance imaging system has a 5-Gauss line that has a maximum dimension of less than or equal to five feet.

Certain aspects of the present disclosure provide methods and apparatus for performing electron paramagnetic resonance (EPR) spectroscopy on a fluid from a flowing well, such as fluid from hydrocarbon recovery operations flowing in a downhole tubular, wellhead, or pipeline. One example method generally includes, for a first EPR iteration, performing a first frequency sweep of discrete electromagnetic frequencies on a cavity containing the fluid; determining first parameter values of reflected signals from the first frequency sweep; selecting a first discrete frequency corresponding to one of the first parameter values that is less than a threshold value; activating a first electromagnetic field in the fluid at the first discrete frequency; and while the first electromagnetic field is activated, performing a first DC magnetic field sweep to generate a first EPR spectrum.

To operate a magnetic resonance tomography system, first analysis signals are received by a main receive antenna and an auxiliary receive antenna. Based thereon, a first interference source and first weighting factors are determined. Second analysis signals are received by the main receive antenna and the auxiliary receive antenna and in accordance with the first weighting factors, a combination of the second analysis signals is created. Based thereon, a second interference source is determined. Second weighting factors are determined in order to suppress the influence of the first interference source and an influence of the second interference source. A magnetic resonance signal is received during an examination phase by the main receive antenna and an interference signal by the auxiliary receive antenna. An interference-suppressed magnetic resonance signal is created as a combination of the magnetic resonance signal and the interference signals depending on the second weighting factors.

An MRI apparatus according to the present embodiment acquires a plurality of MR signals corresponding to read-out directions including a first read-out direction and a second read-out direction intersecting the first read-out direction, and. The MRI apparatus includes processing circuitry and a low-pass filter. The processing circuitry specifies a signal area relating to generation of the MR signals in a subject. The processing circuitry sets a cutoff frequency defining a passband for the MR signals based on the signal area. The low-pass filter filters the MR signals acquired by scanning performed on the subject in the read-out directions using the cutoff frequency. The processing circuitry generates an MR image based on MR data generated by A/D conversion performed on the MR signals output from the low-pass filter.

A magnetic resonance (MR) receive device comprises a coil or coil array including at least one radiofrequency (RF) coil element wherein each RF coil element comprises a coil and a preamplifier connected to amplify an output of the RF coil element to generate an amplified RF signal. The MR receive device further includes an RF-over-Fiber module comprising an optical fiber, a photonic device optically coupled to send an optical signal into the optical fiber, and an RF modulator connected to modulate the optical signal by an MR signal comprising the amplified RF signal.

A system includes a table and a material detection system. The material detection system includes a transmit chain configured to generate first radio frequency (RF) signals and a transmit probe configured to transmit the first RF signals towards an item through open space. The material detection system also includes a receive probe configured to receive second RF signals from the item through open space, where the second RF signals have one or more characteristics indicative of one or more materials within the item. The material detection system further includes a receive chain configured to process the second RF signals and at least one processing device configured to identify the one or more materials within the item using nuclear quadrupole resonance (NQR) spectrometry based on the processed second RF signals. The transmit and receive probes are positioned in an upper portion of the table.