An NMR system includes a radio frequency (RF) NMR application-specific integrated circuit (ASIC) chip configured to generate an RF output signal and a rectifier configured to receive the RF output signal and convert the RF output signal to (a) a direct current (DC) pulsed field gradient (PFG) signal or (b) a DC trigger signal for at least one of (i) activating at least one component of an NMR system external to the NMR RF ASIC chip and (ii) synchronizing at least one component of an NMR system external to the NMR RF ASIC chip.

A method for determining a pulse duration T.sub.90 of a 90° pulse in a nuclear magnetic measuring method. A signal generator has a known generator resistance R.sub.S, wherein a coil has a coil impedance Z.sub.L with a coil resistance R.sub.L and a coil reactance X.sub.L, wherein a coupling circuit has an adjustable matching capacitance C.sub.M and an adjustable tuning capacitance C.sub.T, and wherein the medium has a Larmor precession having an angular Larmor frequency ω.sub.P. The time needed for determining the pulse duration T.sub.90 of the 90° pulse is reduced by the matching capacitance C.sub.M and the tuning capacitance C.sub.T being set so that the angular resonance frequency ω.sub.0 corresponds to the angular Larmor frequency ω.sub.P and by power matching being present between the signal generator and the coil. The coil resistance R.sub.L is determined and the pulse duration T.sub.90 is determined as a function of the coil resistance R.sub.L.

In order to obtain high-quality images easily with high flexibility for imaging conditions and apparatus configuration changes in an MRI apparatus using a multi-element coil, an output pattern identifying a synthesizing mode of the respective reception signals received by the respective elements comprising a reception coil is determined according to imaging conditions in the present invention. The determination is performed so that, for example, at least one of a covering rate of an imaging range, an S/N ratio of the final image, and element utilization efficiency becomes the best. The output pattern is comprised of information identifying one or more elements that use reception signals and a synthetic pattern synthesizing the reception signals among the elements to be used. The synthetic pattern, for example, is selected in advance from among a plurality of synthetic pattern candidates to be stored according to a synthesizing method.

A magnetic resonance tomography unit includes a transmitter, a transmission monitoring device for monitoring an excitation signal from the transmitter, and a plurality of transmit antennas. The magnetic resonance tomography unit also includes a switching device configured to bring the transmission monitoring device selectively into a signal connection to one transmit antenna of the plurality of transmit antennas. A method for operating the magnetic resonance tomography unit is also provided.

An apparatus and method for receiving a magnetic resonance (MR) signal for imaging a patient. The MR signal includes a MR frequency. A radio frequency (RF) coil has first and second end portions. An impedance converter is in electrical communication with the RF coil. A preamplifier in electrical communication with the impedance converter, the preamplifier having a gain. At least one resonant circuit electrically connected to at least one end portion of the RF coil.

A Magnetic Resonance Imaging (MRI) system, including: two separate static magnetic field generators, which are each cylindrical, are axially aligned, and are separated by a rotary load-bearing structure arranged to freely rotate about an axis of a static magnetic field generated by the static magnetic field generators, wherein the rotary load-bearing structure is mounted on thrust bearings which take an axial load between the static magnetic field generators.

An MRI system RF transmit antenna arrangement 3 including an antenna 5 including a length of coaxial cable 51 with an electrically conductive core 52 and an electrically conductive outer shield 53 through which the core runs, with the core having a feed point 52a arranged for electrical connection to an RF source and at least one break 53a being provided in the electrically conductive outer shield partway along the length of coaxial cable so as to divide the electrically conductive outer shield 53 into at least two axially spaced shield portions such that at least one of the shield portions acts as a radiating element when an RF source is connected to the feed point 52a.

A transmission line array is used for explosive/contraband detection using nuclear quadrupole resonance in which the array is driven in-phase with synchrony frequency-swept signals. Each of the balanced transmission lines is fed with a low power swept frequency source and stimulated emissions are picked out with a directional coupler. Location is provided using a cross grid array or a phase detector is used for each balanced line, with phase determining the distance to the sensed substance.

Disclosed herein is a device defining a generally closed volume therein, henceforth known as a “shuttle”, not permanently fixed to a probe or other surface inside the cryostat, into which gas and/or liquid—most preferably helium gas or liquid—can pass into or out of in a controlled and predictable manner. The passage of gas or liquid into the shuttle is preferably via a porous barrier so that sterile conditions can be maintained in the interior of the shuttle.

An apparatus for measuring radio frequency output for a magnetic resonance imaging apparatus includes a plurality of directional couplers, a comparator, a switcher and a converter. The plurality of directional couplers are different in degree of coupling from each other, and attenuate an RF signal which is generated in an RF signal generator and amplified in an RF power amplifier. The comparator compares input-level information of a signal inputted into the RF power amplifier with a threshold value. The switcher switches to any one of the plurality of the directional couplers based on a result of the comparison so as to output an RF signal by the one directional coupler. The converter performs a digital conversion of the RF signal from the one directional coupler so as to output a digital signal.