Abstract: In one aspect, a magnet comprising a pair of pole supports spaced apart from one another and extending in a generally horizontal direction. The magnet includes a pair of flux return members extending between the pole supports so as to define a frame, each of the flux return members including a first columnar section that extends parallel to the polar axis and a second columnar section that extends perpendicular to the polar axis and projects towards the pole. In another aspect, a magnetic resonance imaging system comprises a ferromagnetic frame that is operative to support an upper pole member and a lower pole member along a vertical polar axis such that a gap is defined between the upper and lower pole members and an access floor that is isolated from the ferromagnetic frame and pole members for providing access to the gap.

Abstract: A magnetic resonance imaging magnet includes a ferromagnetic frame. A pair of generally toroidal superconducting coil units overlie interfaces of side walls incorporated in the frame. Each coil unit may include a vessel having hollow support extensions extending into recesses in the side walls. The coil units may further include elongated, low-thermal conductance supports disposed within the support extensions. The frame may include pole stems projecting inwardly from the side walls, and the coils may be disposed in close proximity to the pole stems. Cryocoolers may be mounted to the frame so that the cryocoolers are substantially mechanically isolated from the coils of the coil units, but are in thermal communication therewith. The cryocooler mountings may be arranged for convenient servicing and installation of the cryocoolers.

Abstract: In one aspect, a magnet comprising a pair of pole supports spaced apart from one another and extending in a generally horizontal direction. The magnet includes a pair of flux return members extending between the pole supports so as to define a frame, each of the flux return members including a first columnar section that extends parallel to the polar axis and a second columnar section that extends perpendicular to the polar axis and projects towards the pole. In another aspect, a magnetic resonance imaging system comprises a ferromagnetic frame that is operative to support an upper pole member and a lower pole member along a vertical polar axis such that a gap is defined between the upper and lower pole members and an access floor that is isolated from the ferromagnetic frame and pole members for providing access to the gap.

Abstract: In one example, a magnetic resonance imaging (“MRI”) system comprises a magnetic resonance imaging assembly defining a gap region, a transmitting coil proximate the gap region, and at least one test coil separate from the transmitting coil. The at least one coil is mechanically coupled to the assembly during imaging and the at least one test coil is selectively electrically coupled to the assembly to collect test data. The at least one coil may be coupled to a test fixture coupled to the assembly. The test fixture may be deployable from a first position to a second position for collection of test data. The at least one coil may comprise a first test coil and a second test coil. Methods are also disclosed.

Abstract: A test fixture for testing and monitoring electromagnetic characteristics of a magnetic resonance imaging (“MRI”) system preferably comprises a body portion having a first longitudinal axis and a first coil supported by the body portion. A longitudinal member is preferably connected to the body portion. A second coil is supported by the longitudinal member. The longitudinal member has a second longitudinal axis transverse to the first longitudinal axis. A container for containing a test substance is supported by the longitudinal member within the second coil. The second coil is preferably a transceiver and the test substance is a material capable of emitting a magnetic resonance signal. The longitudinal member is preferably pivotally connected to the body portion and the body portion is preferably telescoping so that the test fixture may be stored in a compact position. Preferably, the test fixture is stored in the gap region in an MRI system.

Abstract: In one aspect the present invention is a method for imaging an infant or minor in a magnetic resonance imaging apparatus. The method preferably comprises positioning an adult in the patient-receiving space or gap of a magnet and affixing a minor, child or infant with an appropriate antenna. The minor, child or infant is then placed in the lap or arms of the adult and imaging proceeds. In another aspect the method may also comprise positioning an adult and a minor, child or infant in the patient-receiving space or gap of a magnet. The infant, child or minor is placed in closed proximity to the adult so that the infant, child or minor and adult can be fitted with a single antenna. Thereafter, an image of a portion of the minor's, infant's or child's anatomy is obtained.

Abstract: A patient is examined by magnetic resonance imaging in different positions relative to gravity by moving the patient relative to the magnet, and the acquired data is compared to show differences in anatomy due to differences in patient position. Individual data elements or groups of plural data elements representing particular locations in one set of image data can be compared with data elements associated with the same locations in another set of image data, to yield a set of comparison image data elements. The comparison data set can be used to detect difference caused by differences in position of the patient.

Abstract: In one example, an illumination system is provided in an MRI system including an open MRI assembly comprising a pole covered by a canopy. The MRI system is within a shielded room. A light source is provided outside of the shielded room, at least one light projector is connected to the canopy, and optical fibers couple the light source to the light projector. The light projector is preferably flexible. The light projector or projectors increase the illumination in the imaging volume, facilitating medical procedures conducted on a subject within the imaging volume.

Abstract: Magnet assembly for use in medical magnetic resonance imaging includes means for increasing flux generation in the gap region to provide the capability of scanning smaller volume regions of a patient at increased levels of scanning resolution. The means for increasing flux generation is mechanical or electromagnetic, is coupled to each of the polar regions and maintains the gap region sufficiently large and unobstructed to allow for access to the patient by several persons during scanning. Tapered outer walls of the polar region proximate the gap region further enhance accessibility to the patient during scanning.

Abstract: Apparatus and method for magnetic resonance imaging. In an aspect, the present invention is an apparatus for magnetic resonance imaging that includes a short bore magnet that is oriented such that, when energized, a static magnetic field is created in a substantially vertical direction. In another aspect, the present invention is a method for performing magnetic resonance imaging using a short bore magnet that is oriented such that, when energized, a static magnetic field is created in a substantially vertical direction.

Abstract: A method for producing a shim piece for a magnetic resonance imaging (MRI) magnet. The shim piece is used to form a shim of a magnet and is designed to suppress eddy currents in the shim created by the introduction of a gradient magnetic field. The shim piece is formed by a plurality of ferromagnetic rods placed side-by-side and surrounded by a dielectric material.

Abstract: A method for fabricating a composite plate for a magnetic resonance imaging magnet. The method including cutting a starting plate having oppositely-directed major surfaces into a plurality of strips. Each of the strips having a width of approximately greater than 9 inches and faces which originally constituted parts of the major surfaces of the starting plate. The strips may be positioned to form the composite plate such that the width of each of the strips is equal to a thickness of the composite plate and the faces of the strips confront one another.

Abstract: A patient is examined by magnetic resonance imaging in different positions relative to gravity by moving the patient relative to the magnet, and the acquired data is compared to show differences in anatomy due to differences in patient position. Individual data elements or groups of plural data elements representing particular locations in one set of image data can be compared with data elements associated with the same locations in another set of image data, to yield a set of comparison image data elements. The comparison data set can be used to detect difference caused by differences in position of the patient.

Abstract: An apparatus and method for magnetic resonance imaging comprising a magnet and means for vertically moving the magnet so as to obtain an image of a portion of a patient's anatomy.

Abstract: A method for producing a shim piece for a magnetic resonance imaging (MRI) magnet. The shim piece is used to form a shim of a magnet and is designed to suppress eddy currents in the shim created by the introduction of a gradient magnetic field. The shim piece is formed by a plurality of ferromagnetic rods placed side-by-side and surrounded by a dielectric material.

Abstract: Magnet assembly for use in medical magnetic resonance imaging includes means for increasing flux generation in the gap region to provide the capability of scanning smaller volume regions of a patient at increased levels of scanning resolution. The means for increasing flux generation is mechanical or electromagnetic, is coupled to each of the polar regions and maintains the gap region sufficiently large and unobstructed to allow for access to the patient by several persons during scanning. Tapered outer walls of the polar region proximate the gap region further enhance accessibility to the patient during scanning.

Abstract: Magnet assembly for use in medical magnetic resonance imaging includes means for increasing flux generation in the gap region to provide the capability of scanning smaller volume regions of a patient at increased levels of scanning resolution. The means for increasing flux generation is mechanical or electromagnetic, is coupled to each of the polar regions and maintains the gap region sufficiently large and unobstructed to allow for access to the patient by several persons during scanning. Tapered outer walls of the polar region proximate the gap region further enhance accessibility to the patient during scanning.

Abstract: A magnet for magnetic resonance imaging has an interior working space within the magnet frame sufficient to accommodate a physician and a patient. Because the physician is positioned inside the magnet frame, the physician has unimpeded access to the patient. Elements of the magnet frame desirably encompass a room, and the magnet frame may be concealed from view of a patient within the room. Preferred embodiments facilitate MRI imaged guided surgery and other procedures performed while the patient is being imaged, and minimize claustrophobia experienced by the patient. Also provided is a magnet having field coils disposed about the of pole portions of the magnet. A diagnostic facility for high volume MRI use is also disclosed.

Abstract: Antennas for use in magnetic resonance imaging (“MRI”) comprise a coaxial cable unit having an inner conductor tuned to a frequency, typically the Larmor frequency of the species of interest, and an outer conductor substantially surrounding the inner conductor and also tuned to the frequency. The inner and outer conductors are inductively coupled. The antennas may be used as receiving and transmitting antennas. In a receiving antenna, the inner conductor provides an output of the antenna. In a transmitting antenna, an input is provided to the inner conductor. Antenna arrays of one or more coaxial cable units, wherein the inner conductors of each unit are electrically connected and the outer conductors are electrically connected, and the units are inductively coupled, may be provided. Additional coaxial cable units may also be provided, inductively coupled to adjacent coaxial cable units. Each coaxial cable unit may comprise multiple inner conductors.

Abstract: Apparatus and methods for performing magnetic resonance imaging. In an embodiment the apparatus comprises a pair of elements spaced apart from each other along a horizontal pole axis so as to define a patient receiving space therebetween. A patient support device is located within the patient receiving space and is operable to accept a patient who enters the patient receiving space in an upright position, e.g., walking. In another embodiment the apparatus comprises a pair of elements supported within a frame. The frame includes upper and lower flux return members that are smaller in a vertical dimension than in a horizontal dimension. In another embodiment, the apparatus comprises a pair of elongated pole members that define an imaging volume having a longer dimension in a vertical direction than in a horizontal direction. An exemplary method includes performing a full body scan of a patient in an upright or sitting position.