Abstract: Some implementations provide a system that includes: a main magnet including a bore and configured to generate a substantially uniform magnetic field in the bore; one or more gradient coils configured to perturb the substantially uniform magnetic field in the bore, wherein perturbing the substantially uniform magnetic field results in a first varying magnetic field outside of the bore; and one or more shielding units located outside of the bore and configured to generate a second varying magnetic field configured to attenuate the first varying magnetic field outside of the bore.

Abstract: Some implementations provide a method that includes: placing a human subject on a moveable platform located in a room with a magnetic resonance imaging (MRI) scanner and a radiation therapy machine; moving the platform into a first position such that the human subject is positioned to be imaged by MRI; operating the MRI scanner while the platform is in the first position to obtain an image of the human subject; moving the platform into a second position such that the human subject is in position to receive radiation therapy from the radiation therapy machine; reducing the magnetic field such that the magnetic field at the radiation therapy machine is below a threshold value; and while the platform is in the second position and the magnetic field at the radiation therapy machine is below the threshold value, operating the radiation therapy machine to perform radiation therapy on the human subject.

Abstract: Systems and methods relating to patch antennas. A patch antenna has a substrate, a resonant metal plate at one side of the substrate, and a ground plane at the other opposite side of the substrate. Two feed pins are used to couple the antenna to other circuitry. The feed pins pass through the substrate and holes in at the ground plane. The feed pins are physically disconnected from both the resonant metal plate and the ground plane. The feed pins are capacitively coupled to the resonant metal plate to provide an electronic connection between other circuitry and the patch antenna.

Abstract: A support stand for supporting a magnetic resonance imaging (MRI) scanner while in operation. A MRI scanner includes a cylindrical housing having a lateral surface extending parallel to a horizontal patient bore to encapsulate a main cylindrical magnet. The cylindrical housing defines a longitudinal footprint dimension and a lateral footprint dimension. The support stand includes a base and a plurality of pillars extending upright from the base. Each respective pillar includes a first end mounted to the base and an opposing second end. The support stand also includes a vibration isolator mounted at the second end of the respective pillars to support the lateral surface of the cylindrical housing. The respective vibration isolators minimize transmission of environment borne vibrations to the MRI scanner or minimize transmission of MRI scanner generated vibrations to the environment.

Abstract: A method for operating a magnetic resonance imaging (MRI) system that includes: accessing data indicating a first region for imaging a portion of a subject, the portion being placed in a main magnet of the MRI system and the main magnet generating a magnetic field; selecting, from a group of available shimming coils, a first subset of shimming coils arranged and configured such that, when the shimming coils in the first subset are driven, a homogeneity of the magnetic field at the first region is increased; and driving the shimming coils in the selected first subset of shimming coils without driving other shimming coils in the group of available shimming coils such that the homogeneity of the magnetic field at the first region increases relative to the homogeneity of the magnetic field at the first region when the shimming coils of the selected first subset are not driven.

Abstract: Systems and methods relating to patch antennas and signal combiner circuits. The invention relates to a circuit with discrete capacitors, inductors and amplifiers arrayed in an arrangement with 2 input ports and one output port. The circuit provides a high degree of reverse electrical isolation between the input ports and the output at the radio frequency. The circuit provides an output that is the vector sum of signals present at the first and second input ports. The circuit additionally provides for introduction of a 90 degree phase shift into either of the two inputs. This circuit can be used with dual feed patch antennas.

Abstract: Some implementations provide a system that includes: a main magnet including a bore and configured to generate a substantially uniform magnetic field in the bore; one or more gradient coils configured to perturb the substantially uniform magnetic field in the bore, wherein perturbing the substantially uniform magnetic field results in a first varying magnetic field outside of the bore; and one or more shielding units located outside of the bore and configured to generate a second varying magnetic field configured to attenuate the first varying magnetic field outside of the bore.

Abstract: Some implementations provide a method for safe operation of a magnetic resonance imaging (MRI) system, the method including: determining, at least in part by using a sensor device, location information that indicates a location of an MR-incompatible object relative to the MRI system, the MRI system generating a polarizing magnetic field for imaging a subject; based on the determined location information, determining, by a control unit associated with the MRI system, that the MR-incompatible object poses an operational hazard to the MRI system; and in response to determining that the MR-incompatible object poses an operational hazard to the MRI system, reducing, by the control unit, a strength of the polarizing magnetic field.

Abstract: Global navigation satellite system (GNSS) radio frequency signals broadcast from geo-stationary satellites 20,000 km above the earth when received by GNSS receivers are fundamentally weak. Accordingly, these GNSS receivers are vulnerable to accidental and deliberate interference from a range of manmade sources as well as natural sources. Existing anti jamming technologies such as controlled reception pattern antennas, adaptive antennas, null-steering antennas, and beamforming antennas etc. are expensive and incompatible with many lower cost and footprint limited applications. However, in many applications the GNSS antenna is mounted upon a fixed or mobile element such that accidental and intentional jammers tend to be in the plane of the antenna or below it. Accordingly, there are presented designs and techniques to improve the anti-jamming or interference performance of GNSS receivers by further reducing the responsivity of the GNSS receiver to signals in-plane or below the plane of the antenna.

Abstract: A medical navigation system is provided for performing at least part of an assessment of a non-living body. The medical navigation system comprises a positioning device having a positioning arm with an end effector at the end of the positioning arm, an imaging device coupled to the end effector, and a controller electrically coupled to the positioning device and the imaging device. The controller has a processor coupled to a memory and a display. The controller is configured to generate a signal to move the positioning arm to position the imaging device through a range of motion to perform a scan of a surface of the body and receive and save as data in the memory signals generated by the imaging device during the range of motion.

Abstract: A system and method of acquiring an image at a magnetic resonance imaging (MRI) system is provided. Accordingly, an analog signal based on a pulse sequence and a first gain is obtained. The analog signal is converted into a digitized signal. A potential quantization error is detected in the digitized signal based on a boundary. When the detection is affirmative, a replacement analog signal based on the pulse sequence is received. At least one portion of the replacement analog signal can be based on an adjusted gain. The adjusted gain is a factor of the first gain. The replacement analog signal is digitized into a replacement digitized signal. At least one portion of the replacement digitized signal corresponding to the at least one portion of the replacement analog signal is adjusted based on a reversal of the factor.

Abstract: Some implementations provide a method for safe operation of a magnetic resonance imaging (MRI) system, the method including: determining, at least in part by using a sensor device, location information that indicates a location of an MR-incompatible object relative to the MRI system, the MRI system generating a polarizing magnetic field for imaging a subject; based on the determined location information, determining, by a control unit associated with the MRI system, that the MR-incompatible object poses an operational hazard to the MRI system; and in response to determining that the MR-incompatible object poses an operational hazard to the MRI system, reducing, by the control unit, a strength of the polarizing magnetic field.

Abstract: A system and method of acquiring an image at a magnetic resonance imaging (MRI) system is provided. Accordingly, an analog signal based on a pulse sequence and a first gain is obtained. The analog signal is converted into a digitized signal. A potential quantization error is detected in the digitized signal based on a boundary. When the detection is affirmative, a replacement analog signal based on the pulse sequence is received. At least one portion of the replacement analog signal can be based on an adjusted gain. The adjusted gain is a factor of the first gain. The replacement analog signal is digitized into a replacement digitized signal. At least one portion of the replacement digitized signal corresponding to the at least one portion of the replacement analog signal is adjusted based on a reversal of the factor.

Abstract: A delta-relaxation magnetic resonance imaging (DREMR) system is provided. The system includes a main field magnet and field shifting coils. A main magnetic field with a strength B0 can be generated using the main filed magnet and the strength B0 of the main magnetic field can be varied through the use of the field-shifting coils. The DREMR system can be used to perform signal acquisition based on a pulse sequence for acquiring at least one of T2*-weighted signals imaging; MR spectroscopy signals; saturation imaging signals and MR signals for fingerprinting. The MR signal acquisition can be augmented by varying the strength B0 of the main magnetic field for at least a portion of the pulse sequence used to acquire the MR signal.

Abstract: Described here are systems and methods for mitigating or otherwise removing the effects of short-term magnetic field instabilities caused by oscillations of the cold head in a cryogen-free magnet system used for magnetic resonance systems, such as magnetic resonance imaging (“MRI”) systems, nuclear magnetic resonance (“NMR”) systems, or the like.

Abstract: Systems and methods for magnetic field-dependent relaxometry using magnetic resonance imaging (“MRI”] are provided. Relaxation parameters, including longitudinal relaxation time (“T1”) and transverse relaxation time (“T2”), are estimated from magnetic resonance signal data acquired at multiple different magnetic field strengths using the same MRI system. By measuring these relaxation parameters as a function of magnetic field strength, T1 dispersion data, T2 dispersion data, or both, are generated. Based on this dispersion data, quantitative physiological parameters can be estimated. As one example, iron content can be estimated from T2 dispersion data.

Abstract: A method of configuring a conducting grid of elements interconnected at intersecting nodes by switches is described.

Abstract: A medical navigation system is provided for registering a patient for a medical procedure with the medical navigation system using fiducial markers. The fiducial markers are placed on the patient prior to a 3D scan and the fiducial markers each have a target for use with a tracking system. The medical navigation system comprises a 3D scanner, a tracking system, a display, and a controller electrically coupled to the 3D scanner, the tracking system, and the display. The controller has a processor coupled to a memory.

Abstract: Optionally adjustable head coil system and methods for enhancing and/or optimizing magnetic resonance imaging, involving a housing, the housing having at least one portion, the at least one portion having a lower portion, an upper portion, and opposing side portions, each at least one portion optionally in movable relation to any other portion for facilitating adjustability, each at least one portion configured to accommodate at least one radio-frequency coil, and the upper and lower portions each optionally configured to overlap and engage the opposing side portions for facilitating decoupling the at least one radio-frequency coil, and a tongue portion optionally in movable relation to any other portion for facilitating adjustability, engageable with the lower portion, and fixably couple-able with a transporter.

Abstract: A delta-relaxation magnetic resonance imaging (DREMR) system is provided. The system includes a main field magnet and field shifting coils. A main magnetic field with a strength B0 can be generated using the main filed magnet and the strength B0 of the main magnetic field can be varied through the use of the field-shifting coils. The DREMR system can be used to perform signal acquisition based on a pulse sequence for acquiring at least one of T2*-weighted signals imaging; MR spectroscopy signals; saturation imaging signals and MR signals for fingerprinting. The MR signal acquisition can be augmented by varying the strength B0 of the main magnetic field for at least a portion of the pulse sequence used to acquire the MR signal.