Abstract: An assembly for delivering optical signals that has a nuclear magnetic resonance system, an optical interface assembly, and a catheter assembly with a fiber optic cable assembly and an optical interface and an antenna. The catheter assembly converts electromagnetic signals received by the antenna into optical signals. The optical interface assembly converts optical signals into electrical signals and electrical signals into optical signals.

Abstract: A restraining apparatus and method for limiting motion on the macro and micro scale during MRI and CT scans, by providing a custom fit, while also improving patient comfort. The restraining apparatus includes a disposable component, including castable and expandable sleeves used to fix the patient into a coil. The castable sleeve encircles the limb of a patient, and is filled with a quickly casting material. The cast material is patient compatible and preferably designed to augment imaging. The resulting cast is MRI compatible, safe and rapid setting, which will decrease the time to set up a patient for scanning, thereby further improving MRI productivity. The expandable sleeve encircles the castable sleeve and is inflatable such that the expandable sleeve conforms to the inner dimensions of a particular MRI coil, CT scanner, or other imaging device. Alternatively, the apparatus includes a castable sleeve for casting around a flex/wrap or surface coil.

Abstract: An apparatus and method for use in medical imaging simulate within an imaging coil normal movements of body parts such as joints, and improve imaging of soft tissue and bony parts as compared to a static system in which images are taken of a joint in only one position. A joint or body parts is moved into various positions in multiple planes within its range of motion while a series of images are taken of the joint in the different positions. The images are collated into a cine format to effectively show the joint in motion. A surface or volume coil may be coupled for movement with the joint or body part and maintained in the proper spatial relationship with the primary coil's electromagnetic field. The systems may be provided as mechanisms usable with existing imaging tables to reduce cost, or may be built into a new imaging table. It is possible to use a larger primary coil, allowing increased range of movement. Traction may be applied to a joint being imaged, in order to load the joint.

Abstract: A radio frequency head coil for resonance imaging analysis of pediatric patients is disclosed. The head coil includes an end cap, an end ring, a plurality of legs connecting the end cap to the end ring, wherein the plurality of legs are spaced apart azimuthally by 45 degrees, and a plurality of drive points, wherein the drive points are bridged using a push-pull configuration.

Abstract: A local coil arrangement for a magnetic resonance system has an antenna arrangement that is arranged in a retainer structure. The retainer structure has a waistband and a perineum element. A person to be examined dons the local coil arrangement like trousers.

Abstract: A method to simulate within an imaging coil normal movements of body parts such as joints, and improve imaging of soft tissue and bony parts as compared to a static system in which images are taken of a joint in only one position. A joint or body parts is moved into various positions in multiple planes within its range of motion while a series of images are taken of the joint in the different positions. The images are collated into a cine format to effectively show the joint in motion. A surface or volume coil may be coupled for movement with the joint or body part and maintained in the proper spatial relationship with the primary coil's electromagnetic field.

Abstract: A magnetic resonance (MR) imaging system having an apparatus and method for providing appropriately located MR images acquired using a surface coil is disclosed herein. The system includes a controller configured to automatically synchronize a position of an image acquisition plane with respect to a position of the surface coil. To perform the synchronization, the system further includes a monitoring apparatus to monitor at least one of the position of the image acquisition plane and the surface coil.

Abstract: A transmitter consists of a plurality of magnetic transmitters, each of which is substantially planar and made of a spiral shaped conductor. The result is a transmitter having a substantially uniform cross-sectional current density along the radial direction of the spiral from the center to the periphery. Near the plane of a given spiral, magnetic vectors produced by such a conductor arrangement have improved angular characteristics as compared to prior art systems. This results in a larger region with useful vector crossing angles and operation of the system is enhanced as compared to prior art techniques. The transmitters produce magnetic fields which have a monotonically increasing intensity as one approaches the center of the transmitter spiral from any given direction. This feature simplifies and increases the accuracy of sensor position determination.

Abstract: A MRI array coil includes a first anterior array and a second anterior array where the first and second anterior arrays each have a rigid longitudinal support, the supports being hingingly joined; and a first posterior array and a second posterior array. The first arrays are adapted to image a first volume of interest and the second arrays are adapted to image a second volume of interest, where the volumes of interest are longitudinally displaced.

Abstract: A magnetic field generator for therapeutic applications develops a static or direct current (DC) magnetic field. The generator is self-contained, and also concentrates the magnetic lines of flux in a specific area. A recipient of the therapy may thus place a limb, typically a wrist or lower portion of an arm, in the area of concentrated magnetic flux of the static magnetic field.

Abstract: A fixture such as a local receiver coil is secured to the patient support of a magnetic resonance imaging system so that the fixture remains in position relative to the support even when the support is in a vertical orientation. The positioning apparatus is arranged to allow adjustment of the fixture position, but to limit such adjustment so that the fixture cannot interfere with the poles or other elements defining the patient-receiving gap of the magnet during movement of the patient support.

Abstract: A magnetic resonance apparatus has a basic field magnet system for generating a basic magnetic field and a coil system with a coil arrangement, wherein a course of a current-carrying conductor of the coil arrangement for generating a predetermined target magnetic field is determined according to a method that allows for linear secondary conditions. A noise-causing mechanical oscillation of the coil system as a result of Lorentz forces that act on the current-carrying conductor in the basic magnetic field is thereby taken into consideration by one of the linear secondary conditions, and the course of the conductor is additionally determined by the method so that the noise-causing oscillation is diminished.

Abstract: A TEM resonator RF coil with excellent operating characteristics comprising a plurality of ring segments on the orifice capable of being segmented by slits on the orifice are installed with a first conducting pattern connecting to the line element, a second conducting pattern disposed symmetrically on the left and right of the first conducting pattern, a capacitor connecting these conducting patterns, and a connection means spanning the adjacent ring segments and connecting the second conducting patterns.

Abstract: An incubator arrangement and radiofrequency (RF) coil are provided for use in a Magnetic Resonance Imaging (MRI) system. The incubator arrangement comprises an enclosure adapted to support a subject in a magnet of the MRI system during imaging and a radiofrequency coil disposed within the enclosure. The RF coil is adapted to provide visual and physical access to the subject, and further adapted to obtain a selected signal to noise ratio.

Abstract: An apparatus, system and method for calibrating a movable receiver coil in a magnetic resonance imaging environment is described. The method of the invention calibrates the movable receiver coil by dividing the receiver coil into parts and determining electromagnetic interactions of the parts in the environment. The method further includes (1) estimating orientation and position information corresponding to the receiver coil and (2) associating electromagnetic interaction data with records such as (a) responses of the receiver coil in various tissue environments to emissions caused by stimuli from external magnetic resonance coils, (b) high-resolution external receiver coil records of emissions from same environments, and (c) measures of self-interactions and mutual interactions among the parts of the receiver coil. The parts of the receiver coil may be connected in series or parallel.

Abstract: A description is given of a catheter for use during examination of an object by means of a magnetic resonance (MR) imaging apparatus. Also described is a method of forming an MR image and of visualizing in the MR image a position of the catheter (10) introduced into an object to be examined and also of an MR imaging apparatus for carrying out such a method. The catheter (10) includes a transmission unit (11) and a transmission antenna (116) for forming and emitting, respectively, pulses of RF oscillations of a first frequency (f1) whereby nuclear magnetization is excited in a near field of the transmission antenna in the object to be examined, that is, in such a manner that this nuclear magnetization can be picked up by RF receiving coils of the MR imaging apparatus and reproduced in an MR image so as to visualize a position of the catheter.

Abstract: The present invention is a technique of, and system for, imaging vascular anatomy over distance considerably greater than the maximum practical field of view of a magnetic resonance imaging system while using substantially one contrast agent injection. The technique and system of the present invention acquires image data of a plurality of image volumes which are representative of different portions of the patient's body. The image data of each image volume includes image data which is representative of the center of k-space. The acquisition of image data which is representative of the center of k-space is correlated with a concentration of contrast agent in the artery(ies) residing in the image volume being substantially greater than the concentration of contrast agent in veins and background tissue adjacent to the artery(ies).

Abstract: An RF coil construction (40, 40′) includes removable, relocatable, and/or detachable sections (42, 44) that are inherently decoupled. The sections can be relocated, removed, or exchanged with sections having different coil sizes or coil configurations, allowing the coil configuration to be tailored to a desired imaging procedure and region of the brain. The coil construction provides space for stimulation devices and adjusting patient access and comfort. Since the operator can select coil removal or placement to reduce the amount of data outside the region of interest, the coil construction can also reduce scanning and reconstruction time, reduce artifacts, and provide increased temporal resolution and image throughput.

Abstract: Microcoils can be used in medical devices to enhance RF response signals and to create fields to enhance imaging capability in MRI imaging systems. An improved microcoil design includes a device to be inserted into a patient comprising a solid body having at least one pair of radially opposed microcoils physically associated with the solid body, each microcoil having an outside microcoil diameter of 6 mm or less, individual windings of each microcoil together defining a geometric plane for each microcoil, and the plane of each microcoil being parallel to the plane of another microcoil in the pair of radially opposed microcoils.

Abstract: An inherently de-coupled sandwiched solenoidal array coil (SSAC) is disclosed for use in receiving nuclear magnetic resonance (NMR) radio frequency (RF) signals in both horizontal and vertical-field magnetic resonance imaging (MRI) systems. In its most basic configuration, the SSAC comprises two coaxial RF receive coils. The first coil of the array has two solenoidal (or loop) sections that are separated from one another along a common axis. The two sections are electrically connected in series but the conductors in each section are wound in opposite directions so that a current through the coil sets up a magnetic field of opposite polarity in each section. The second coil of the SSAC is disposed (“sandwiched”) between the two separated solenoidal sections of the first coil in a region where the combined opposing magnetic fields cancel to become a null.

Abstract: An MRI array coil system for neurovascular and spine imaging of a human includes a neck coil having a split top; a dome-like head coil having a dome region, the head coil being slidable between a closed position adjacent to the neck coil and an open position spaced away from the neck coil; a posterior torso coil attached to the neck coil; and an anterior torso coil adapted to cooperate with the posterior coil.

Abstract: The apparatus and method alters the intravenous delivery of pharmaceuticals to enhance imaging of the vasculature of an animal. The apparatus includes a pressure-inducing component that is sized to attach circumferentially to an extremity of an animal thereby impeding arterial blood flow causing said pharmaceuticals to remain at selected levels within the vasculature.

Abstract: Microcoil designs are provided that enable unique RF response Field profiles that are particularly useful in MRI imaging procedures, particularly where fields of view outside of the medical device are desirable. These devices are particulatly for use within an organism, the device comprising an element having at least one RF receiver, the coils of said microcoils defining a cross-section that lies in a plane oriented at 0 to 90 (or 0 to 80) degrees to the longest axis of the device. Another way of describing the device is as a device for use in an organism, the device comprising an element having at least one wound microcoil with at least three windings on the microcoil. Each winding has an aspect ratio of greater than one. The aspect ratio of each winding is measured as the ratio of longest to shortest dimension in a cross section situated approximately transverse to the winding axis of the coil windings, the winding axis also being transverse to the longest axis of said device.

Abstract: A plurality of objects are concurrently studied in a common MRI apparatus wherein the RF excitation is distributed to one plurality of K RF coils of N said pluralities of RF coils and one of each of said N is switched to a corresponding one of K RF receivers. The interaction of the several coils is further minimized by selectably detuning each coil except for an active coil(s).

Abstract: An MRI system using an open type magnet, wherein two coils different in radius for generating gradient magnetic fields in a vertical direction are arranged in the open type magnet for generating a static magnetic field in the vertical direction. Currents are caused to flow through the two coils in directions opposite to each other to improve the degree of uniformity of the magnetic field in the vertical direction, thereby reducing the degradation thereof by equal to or smaller than 2 figures compared with the degree of uniformity of the static magnetic field generated by the existing MRI system. The positional information about a read-out direction is given through the dynamic control for the RF magnetic field to give the positional information about other two axes directions based on the gradient magnetic field having strength much larger than that of nonuniformity of the magnetic field.

Abstract: A method for winding on embedded b-zero coil maintains the integrity of superconducting main coil and the b-zero wire during coil winding and during normal operation of a superconducting MRI magnet. The b-zero coil is co-wound with an aluminum overwrap while the aluminum overwrap is being wound onto the superconducting MRI coil. The two-wire geometries are selected such that the height or thickness of the aluminum overwrap is greater than or equal to the height or thickness of the b-zero coil wire. The b-zero coil wire sits in a cavity that is created by adjacent turns.

Abstract: The invention includes a device for detection of respiratory motion of a subject during acquisition of an magnetic resonance image that includes a lever having a proximal and a distal end, a counterweight on the proximal end of the lever, a fulcrum, a pickup coil attached to the distal end of the lever, and a MRI machine that has a radio frequency resonator, a gradient coil, and a magnetic field, wherein the lever, fulcrum, counterweight, and pickup coil are positioned so that the lever moves as the subject breathes, the pickup coil is also positioned so that it does not cause artifacts in the MRI image, and the device as a whole generates an electrical signal that can be used to detect and monitor the respiratory motion of the subject.

Abstract: A magnetic resonance imaging apparatus has a patient support (1) moveable on runners (2) along a beam (3) into a bore (4). The r.f. coil (7) is secured to the patient support so as to travel axially with the patient support when the patient enters the bore. The r.f. coil is also moveable laterally to enable off-centre as well as central regions of the patient to be imaged. The apparatus is particularly suited to continuous scan. The width of the central section of the coil (7) may also be variable in a lateral direction to accommodate patients of different size.

Abstract: The present invention provides a vaginal imaging device for quantifying morphological and biochemical changes in the pelvic floor muscles as well as monitoring muscular function. Specifically, the present invention provides a vaginal imaging probe comprising a single or dual tuned resonator for both nuclear magnetic resonance imaging and spectroscopy of the pelvic floor musculature.

Abstract: Herein is disclosed a magnetic resonance imaging probe, having a probe shaft including a magnetic resonance antenna, and a spring tip attached to a distal end of the antenna.

Abstract: The invention relates to a method of and a device for exciting the nuclear magnetization in a limited volume of an object to be examined, utilizing a microcoil (L) which is present in the volume and is attached, for example, to an interventional instrument during the formation of a magnetic resonance image of the object to be examined. The excitation of the nuclear magnetization is performed by at least one RF pulse whose frequency spectrum does not overlap the range of the spin resonance spectrum, so that no nuclear magnetization is excited outside the close range of the microcoil in the object to be examined. The microcoil, however, is provided with an active or passive circuit (for example, it is wired together with at least one capacitance (C) and a non-linear component (D1, D2) so as to form a non-linear resonant circuit) which locally generates an RF signal from the RF pulse.

Abstract: In a method for operating a magnetic resonance tomography apparatus, a basic magnetic field is produced and at least one magnetic gradient field is switched that comprises a main field component that is co-linear to the basic magnetic field, having a predetermined main gradient, this gradient field also having at least one accompanying field component that is perpendicular to the main field component, and also having a linearity volume. An additional magnetic field that is as homogenous is possible is thereby switched (activated) that extends beyond the linearity volume, and this additional magnetic field is switched at least for a duration of time in which the gradient field is also switched. This additional magnetic field is oriented such that it reduces at least one of the field components in at least one region of anticipated stimulation of the examination subject.

Abstract: A method and apparatus for producing an image of a region of interest using a Magnet Resonance Imaging (MRI) system comprises the steps of acquiring a plurality of under-sampled MR data sets from a plurality of radiofrequency (RF) coils forming an array and combining the plurality of under-sampled MR data sets to produce the image. Each of the RF coils has a non-uniform sensitivity.

Abstract: High-frequency coil arrangement for a magnetic resonance tomography apparatus and magnetic resonance tomography apparatus employing such an arrangement have a surface coil and a loop coil for enclosing the examination subject. Both coils are fashioned for receiving the same first polarization component. A switching device is present for alternately deactivating and/or activating the surface coil and the loop coil. The two coils are preferably arranged on a common carrier structure that is bendable.

Abstract: A technique is disclosed for shielding rf magnetic fields in MRI systems. An rf shield is embedded in a gradient coil structure including X-, Y- and Z-axis coils. The rf shield is positioned between an inner gradient coil which is inherently decoupled from the rf field, and the remaining coils which require rf shielding. The inner gradient coil may be a Z-axis coil wound as a solenoid, the field of which is generally orthogonal with respect to the rf magnetic field. The rf shield is thereby placed at an enhanced distance from the rf coil, providing greater efficiency and permitting energy levels to be reduced to obtain the desired rf magnetic field strength.

Abstract: In medical MRI apparatus it is often desirable to maintain a connection with the patient 58 to be examined, for example in order to observe the patient by means of a television camera 62 or to monitor physical functions like the heart rate or blood pressure. It is often necessary to use electrically powered connection equipment 62, 64 which is located in or very close to the imaging area 29, the supply lines 66, 68 also being located in the imaging area so that the (precisely defined) fields required for imaging would be disturbed thereby. According to the invention the supply lines are subdivided into segments 72-i, each of which has a length shorter than ¼ of the wavelength of the RF field; these segments are separated from one another by inductances 74-i. Consequently, the supply line does not present itself as an energy absorbing conductor to the RF field, so that the RF field is not disturbed thereby.

Abstract: A system for and method of determining and compensating for the effect of a field influencing object on a field sensor, preferably a coil, that is within a navigational domain. The navigational domain contains navigational magnetic energy and disturbing magnetic energy, and the field influencing object produces the disturbing magnetic energy in response to the navigational magnetic energy. The correction system includes a first transmitter for projecting into the navigational domain field energy in a first waveform sufficient to induce a first signal value in the sensing coil. The system also includes a second transmitter for projecting into the navigational domain field energy in a second waveform sufficient to induce a second signal value in the sensing coil. The system further includes a signal processor for receiving the first signal value and for receiving the second signal value to determine the effect of the electrically conductive object on the field senior.

Abstract: An inherently de-coupled sandwiched solenoidal array coil (SSAC) is disclosed for use in receiving nuclear magnetic resonance (NMR) radio frequency (RF) signals in both horizontal and vertical-field magnetic resonance imaging (MRI) systems. In its most basic configuration, the SSAC comprises two coaxial RF receive coils. The first coil of the array has two solenoidal (or loop) sections that are separated from one another along a common axis. The two sections are electrically connected in series but the conductors in each section are wound in opposite directions so that a current through the coil sets up a magnetic field of opposite polarity in each section. The second coil of the SSAC is disposed (“sandwiched”) between the two separated solenoidal sections of the first coil in a region where the combined opposing magnetic fields cancel to become a null.

Abstract: An MRI apparatus and method for reducing wrap around artifacts during image reconstruction is provided. An RF coil and control configuration includes a center coil and at least one pair of end RF coils configured to encode and excite spins over an adjustable field-of-view (FOV). The adjustable FOV has at least two size designations in response to an FOV size request input. The control connected to the RF coil assembly is capable of switching between the FOV size designations by switching power to activate a center coil alone or the center coil in conjunction with the end coils in unison.

Abstract: In a method and magnetic tomography apparatus wherein over-convolutions in the phase coding direction in magnetic resonance tomography are avoided, orthogonal slices are measured as overview presentations (localizers) in a first step and slices for the following measurement series are then determined. Overlapping phases and the magnitude of the appertaining signal are calculated and a warning is emitted when this over-convoluted signal exceeds a reference value. A selection possibility is then offered for reducing the phase coding steps and enlarging the field of view and, if selected, the phase coding step width is automatically reduced.

Abstract: For the purpose of providing an RF coil that enables satisfactory imaging of the prostate, the RF coil is composed of a first saddle coil and a second saddle coil. The first saddle coil has two loop portions opposed to each other so that they can sandwich the inferior abdomen of a human body antero-posteriorly. The second saddle coil has two loop portions opposed to each other so that they will permit insertion of the inferior limbs of a human body thereinto and can sandwich the inferior abdomen thereof laterally.

Abstract: A capacitor decoupling network allows the production of a multi-loop local coil for magnetic resonance imaging without overlap of the loops and/or with decoupling between both adjacent and non-adjacent coils. The former design may find application for new MRI techniques such as SMASH and SENSE.

Abstract: An MRI apparatus and method for reducing wrap around artifacts during image reconstruction is provided. An RF coil and control configuration includes a center coil and at least one pair of end RF coils configured to encode and excite spins over an adjustable field-of-view (FOV). The adjustable FOV has at least two size designations in response to an FOV size request input. The control connected to the RF coil assembly is capable of switching between the FOV size designations by switching power to activate a center coil alone or the center coil in conjunction with the end coils in unison.

Abstract: The invention relates to an interventional magnetic resonance method utilizing a microcoil. The method enables localization of an interventional instrument by detection of magnetic resonance signals from the surroundings of the microcoil under the influence of magnetic field gradients. The outstanding reliability and the high speed of the method are due to the application of spatially non-selective RF pulses in conjunction with a sequence of gradient pulses in non-colinear directions. The localization method can be used inter alia for angiography wherein the signal intensity is used to determine the amount of blood present in the blood vessel. The invention also relates to a magnetic resonance apparatus for carrying out the method.

Abstract: In a method for operating a magnetic resonance apparatus, and a magnetic resonance apparatus for implementing the method, the magnetic resonance apparatus having a gradient system containing at least one gradient coil for generating a gradient field at least within an imaging volume, and at least one shield coil operable independently of the gradient coil for generating a shielding field with which the gradient field can be neutralized in a prescribable region, the gradient system is operated in an operating mode wherein the shield coil is operated for intensifying the gradient field within the imaging volume.

Abstract: A plurality of objects are concurrently studied in a common MRI apparatus wherein the RF excitation is distributed to one plurality of K RF coils of N said pluralities of RF coils and one of each of said N is switched to a corresponding one of K RF receivers. The interaction of the several coils is further minimized by selectably detuning each coil except for an active coil(s).

Abstract: The present invention includes a stereotactic system and a method of use for determining vectors involving no electronic components. The stereotactic system comprises a lower plane device and an upper plane device, each having a pair of non-parallel image-conspicuous lines. The system can be used with magnetic resonance imagining (MRI), computed tomography (CT), plain film, radioscopy or fluoroscopy. The relationship of the lines enables a medical practitioner to accurately, directly, and easily determine the vector along which a medical device should be advanced to reach a target within the patient's body using a minimized number of images. As an option, the system may include an additional disposable lower plane device having a pair of non-parallel image-conspicuous lines adapted to determine a skin entry point on the patient for the medical device.

Abstract: The invention relates to an MR apparatus which includes a cylindrical main field magnet for generating a uniform, steady magnetic field whose cylindrical shape defines a symmetry axis, a gradient coil system which encloses the symmetry axis and includes a plurality of gradient coils, an RF coil system which is situated inside the gradient coil system and includes a plurality of mutually offset conductors which extend parallel to the symmetry axis, and a table top for accommodating an object to be examined.

Abstract: The apparatus and method alters the intravenous delivery of pharmaceuticals to enhance imaging of the vasculature of an animal. The apparatus includes a pressure-inducing component that is sized to attach circumferentially to an extremity of an animal thereby impeding arterial blood flow causing said pharmaceuticals to remain at selected levels within the vasculature.

Abstract: A technique is disclosed for shielding rf magnetic fields in MRI systems. An rf shield is embedded in a gradient coil structure including X-, Y- and Z-axis coils. The rf shield is positioned between an inner gradient coil which is inherently decoupled from the rf field, and the remaining coils which require rf shielding. The inner gradient coil may be a Z-axis coil wound as a solenoid, the field of which is generally orthogonal with respect to the rf magnetic field. The rf shield is thereby placed at an enhanced distance from the rf coil, providing greater efficiency and permitting energy levels to be reduced to obtain the desired rf magnetic field strength.