Abstract: A system for guiding a medical intervention is disclosed. The system employs a device guide that operates on the surface of a sphere that is centered on a selected target.

Abstract: A system for guiding a medical intervention is disclosed. The system employs a device guide that operates on the surface of a sphere that is centered on a selected target.

Abstract: A birdcage coil includes: (a) a pair of conductive end rings, each having a generally domed shape in axial cross section; (b) a plurality of conductive, elongated rungs extending between the pair of conductive end rings in an axial direction; and (c) an LC delay circuit incorporated into the pair of rings and the plurality of elongated rungs, where the LC delay circuit includes a plurality of capacitive elements and a plurality of inductive elements. In the present invention circumferential spacing between adjacent elongated rungs is varied to improve homogeneity of the volume excitation. Alternatively, or in addition, LC circuit capacitance and/or inductance values are varied to improve homogeneity of the volume excitation.

Abstract: A birdcage coil for a magnetic resonance imaging (MRI) system, the birdcage coil includes: a relatively planar birdcage coil section, including a pair of relatively planar ring portions and a plurality of conductive, elongated rungs extending between the pair of relatively planar ring portions; and a relatively domed birdcage coil section, including a pair of relatively domed ring portions and a plurality of conductive, elongated rungs extending between the pair of relatively domed ring portions. The relatively domed birdcage coil section is releasably coupled to the relatively planar birdcage coil section. In an embodiment, at least two sets of the relatively planar and domed birdcage coil sections are provided, where each of the at least two sets is configured to a different MRI application.

Abstract: Apparatus and methods to add heat capacity to a cryogenic apparatus such as a superconducting magnet are provided. A body of liquid cryogen having a relatively high heat capacity is stored at cryogenic temperatures in a low temperature vessel that is thermally linked to a cold mass within the cryogenic apparatus. The low temperature vessel is connected to a manifold system located on the exterior of the cryogenic apparatus. The manifold is further connected to a room temperature vessel so that gas is allowed to freely move between the low temperature and room temperature vessels.

Abstract: Apparatus and methods to create and/or enhance thermal gradients in a body of cryogenic liquid contained in a vessel that is actively cooled by a cryocooler is provided. With such apparatus and/or methods temperature in one part of the body of liquid can be made lower than the temperature in another part of the body of liquid. Thus, the apparatus and/or methods enables cryogenic operation of a device at a temperature that is below that of the boiling point of the cryogenic liquid while simultaneously allowing the liquid to be at a pressure greater than atmospheric pressure to obviate the risk of air entering the cryogenic space. These apparatus and/or methods may find use in cryogenic systems used for magnetic resonance imaging, cyclotrons for radioisotope generation, cyclotrons for radiation therapy, high-energy particle accelerators, magnet systems for crystal growth and the like.

Abstract: A birdcage coil for a magnetic resonance imaging (MRI) system, the birdcage coil includes: a relatively planar birdcage coil section, including a pair of relatively planar ring portions and a plurality of conductive, elongated rungs extending between the pair of relatively planar ring portions; and a relatively domed birdcage coil section, including a pair of relatively domed ring portions and a plurality of conductive, elongated rungs extending between the pair of relatively domed ring portions. The relatively domed birdcage coil section is releasably coupled to the relatively planar birdcage coil section. In an embodiment, at least two sets of the relatively planar and domed birdcage coil sections are provided, where each of the at least two sets is configured to a different MRI application.

Abstract: A birdcage coil for a magnetic resonance imaging (MRI) system is provided. The birdcage coil includes: (a) a pair of conductive end rings, each having a generally domed shape in axial cross section; (b) a plurality of conductive, elongated rungs extending between the pair of conductive end rings in an axial direction; and (c) an LC delay circuit incorporated into the pair of rings and the plurality of elongated rungs, where the LC delay circuit includes a plurality of capacitive elements and a plurality of inductive elements. In the present invention circumferential spacing between adjacent elongated rungs is varied to improve homogeneity of the volume excitation. Alternatively, or in addition, LC circuit capacitance and/or inductance values are varied to improve homogeneity of the volume excitation.

Abstract: A birdcage coil for a magnetic resonance imaging (MRI) system is provided. The birdcage coil includes: (a) a pair of conductive end rings, each having a generally domed shape in axial cross section; (b) a plurality of conductive, elongated rungs extending between the pair of conductive end rings in an axial direction; and (c) an LC delay circuit incorporated into the pair of rings and the plurality of elongated rungs, where the LC delay circuit includes a plurality of capacitive elements and a plurality of inductive elements. In the present invention circumferential spacing between adjacent elongated rungs is varied to improve homogeneity of the volume excitation. Alternatively, or in addition, LC circuit capacitance and/or inductance values are varied to improve homogeneity of the volume excitation.

Abstract: A magnetic resonance (MR) signal detector grid assembly adapted for detection of signals in a magnetic resonance imaging apparatus is disclosed. The MR signal detector grid assembly may include a non-resonant grid of a plurality of wire elements and a plurality of detector elements. At least one end of a selected wire element may be electrically attached to an end of at least one other selected wire element. At least one of the detector elements may be configured to detect an MR signal induced on a wire element in the non-resonant grid. The plurality of wire elements may be substantially in the same plane, and the plane may be warped into an arbitrary three-dimensional surface. The three-dimensional surface may have a shape that is cylindrical, partially cylindrical, and/or saddle-shaped. The plurality of wire elements may form a rectilinear grid, a hexagonal grid, a triangular grid, and/or a pseudo-random grid.

Abstract: A system for guiding a medical intervention is disclosed. The system employs a device guide that operates on the surface of a sphere that is centered on a selected target.

Abstract: A system for landmarking a patient during a medical procedure, such as Magnetic Resonance (MR) Imaging, is disclosed. A video display monitor displays images from a video camera positioned in a location relative to an isocenter of the medical device, and a patient's position is adjusted to align a feature of interest on the patient with a reference marker displayed on the monitor. A landmark may be declared on the feature of interest such that the system can move the patient to place the landmarked feature of interest substantially at the isocenter of the medical device.

Abstract: A birdcage coil for a magnetic resonance imaging (MRI) system is provided. The birdcage coil includes: (a) a pair of conductive end rings, each having a generally domed shape in axial cross section; (b) a plurality of conductive, elongated rungs extending between the pair of conductive end rings in an axial direction; and (c) an LC delay circuit incorporated into the pair of rings and the plurality of elongated rungs, where the LC delay circuit includes a plurality of capacitive elements and a plurality of inductive elements. In the present invention circumferential spacing between adjacent elongated rungs is varied to improve homogeneity of the volume excitation. Alternatively, or in addition, LC circuit capacitance and/or inductance values are varied to improve homogeneity of the volume excitation.

Abstract: An MR loop coil design incorporates a balun into the loop coil. With this approach, some components of the coil may be simultaneously part of the imaging coil and the balun. Further, with this approach the number of components used to build an MR coil may be reduced, which may result in a reduction in cost, weight and size. This MR loop coil design may also be used to build phased array coils from the smaller loop size. Such an approach may use small feeder circuit boards oriented generally perpendicular to the coil elements to reduce interactions between the feeder boards and the coils. Such feeder boards may also be made smaller than conventional feeder circuits because the integrated balun coil design may reduce the number of components needed to create balanced coils in the array.

Abstract: A magnetic resonance (MR) signal detector grid assembly adapted for detection of signals in a magnetic resonance imaging apparatus is disclosed. The MR signal detector grid assembly may comprise a non-resonant grid of a plurality of wire elements and a plurality of detector elements. At least one end of a selected wire element may be electrically attached to an end of at least one other selected wire element. At least one of the detector elements may be configured to detect an MR signal induced on a wire element in the non-resonant grid. The plurality of wire elements may be substantially in the same plane, and the plane may be warped into an arbitrary three-dimensional surface. The three-dimensional surface may have a shape that is cylindrical, partially cylindrical, and/or saddle-shaped. The plurality of wire elements may form a rectilinear grid, a hexagonal grid, a triangular grid, and/or a pseudo-random grid.

Abstract: The present disclosure describes examples of magnetic resonance (MR) detector that may replace conventional MR imaging coil arrays. The present disclosure generally describes an example coil design approach that may reduce the number of components for MR imaging devices and may eliminate the need of tissue matching. In some examples, this approach implements a non-resonant grid in which MR-induced currents are allowed to flow unconstrained over the grid (unlike conventional phased array coils in which current is constrained to flow within each loop). Current in each element of the grid may be detected with inductively-coupled pickup loops, which may be attached to independent receiver channels of the MR imaging system. In one example, individual integrated balun pickup coils may be inductively coupled to each grid element. Other connection arrangements, however, may be employed if desired.

Abstract: The present disclosure describes examples of magnetic resonance (MR) detector that may replace conventional MR imaging coil arrays. The present disclosure generally describes an example coil design approach that may reduce the number of components for MR imaging devices and may eliminate the need of tissue matching. In some examples, this approach implements a non-resonant grid in which MR-induced currents are allowed to flow unconstrained over the grid (unlike conventional phased array coils in which current is constrained to flow within each loop). Current in each element of the grid may be detected with inductively-coupled pickup loops, which may be attached to independent receiver channels of the MR imaging system. In one example, individual integrated balun pickup coils may be inductively coupled to each grid element. Other connection arrangements, however, may be employed if desired.

Abstract: An MR loop coil design incorporates a balun into the loop coil. With this approach, some components of the coil may be simultaneously part of the imaging coil and the balun. Further, with this approach the number of components used to build an MR coil may be reduced, which may result in a reduction in cost, weight and size. This MR loop coil design may also be used to build phased array coils from the smaller loop size. Such an approach may use small feeder circuit boards oriented generally perpendicular to the coil elements to reduce interactions between the feeder boards and the coils. Such feeder boards may also be made smaller than conventional feeder circuits because the integrated balun coil design may reduce the number of components needed to create balanced coils in the array.

Abstract: An apparatus and method for correcting magnetic resonance temperature measurements is disclosed. In one aspect, the method identifies monitoring regions of interest outside a therapeutic region of interest. Next, a pulse sequence sensitive to changes in T1 and proton density is used to measure the temperature changes in these regions. Next, the PRFS is measured in these same regions. The PRFS in these regions will be caused both by the desired shift from temperature change, and the undesired shift from background magnetic field changes. Using the measured temperature changes from the T1-method, the component of the PRFS due to actual temperature changes is subtracted from the PRFS method, leaving only the component caused by the unwanted magnetic field changes. This analysis is performed separately for each region. At the end of this step, one has measured the change in background magnetic field within each region.

Abstract: The present invention related to devices and methods for using ferrite alignment keys in wireless remote sensor assemblies. In one aspect, the invention provides wireless resonant sensor assemblies comprising a pick-up coil, a ferrite alignment key positioned in and extending from the pick-up coil, and wireless resonant sensor having a receiving element wherein the pick-up coil and the wireless resonant sensor align upon insertion of the ferrite alignment key into the receiving element. The ferrite alignment key may also be part of a resonant sensor such that insertion of a pick-up coil into a receiving element of the alignment key results in a configuration where the alignment key is positioned in and extended from the pick-up coil. Methods of measuring one or more parameters of a monitoring system are also provided. The insertion of the ferrite alignment key aligns the pick-up coil and wireless resonant sensor thereby increasing sensing of the wireless resonant sensor by the pick-up coil.