Abstract:
A cable guide for use in a nuclear magnetic resonance tomography apparatus is provided for cable for making electrical connections between devices secured to a patient bed and devices disposed outside of the examination space. The cable guide is a grounded, electrical cable channel disposed beneath the patient bed and above the lower sub-antenna of a whole-body antenna and above at least one wall of the examination space. The cable channel has a V-shape, and is rounded at an edge facing the examination space, this edge projecting beyond the height of the lower sub-antenna. The cable guide substantially protects the cable against coupling with other components. The examination space remains free of built-in units.
Abstract:
Apparatus for generating a magnetic high-frequency field and/or for receiving corresponding high-frequency signals in a nuclear spin resonance apparatus, especially in medical technology, contains a surface coil which can be arranged within an at least partially homogeneous magnetic field region of a magnetic field which is generated by a base field magnet and is oriented along an axis, in the vicinity of a body or body part to be examined. In this apparatus, the sensitivity of the surface coil in the depth direction should be increased and be adjustable. In order to accomplish this adjustment, the surface coil has several turns which enclose each other at least partially and which are arranged at different geometrical points. Each turn preferably comprises substantially a single conductor section or of several conductor sections arranged in a group, the current flow directions being opposed to each other in mutually adjacent turns.
Abstract:
A method of forming at least one primary microstructure on a substrate (10) is described. A relief structure (14) is provided for contacting a layer of microstructure forming fluid (12), the relief structure including (i) at least one primary cavity (16) which defines the at least one primary microstructure; (ii) at least one secondary cavity (18) for receiving residual microstructure forming fluid; and (iii) at least one bearing surface (24) for bearing against the substrate, the at least one bearing surface separating the at least one primary cavity and the at least one secondary cavity. A layer of microstructure forming fluid is provided between the relief structure and the substrate and at least one of the substrate and the relief structure is moved relative to the other so that the bearing surface comes to bear against the substrate. The movement displaces a portion of the microstructure forming fluid to occupy the at least one primary cavity, forming the at least one primary microstructure and displaces the residual microstructure forming fluid to be received by, and at least partially occupy, the at least one secondary cavity.
Abstract:
A surface coil for a nuclear magnetic resonance apparatus has a number of conductor sections arranged relative to each other. These sections can be connected to one another and to a reception unit by employing switches to enclose a preferable conductor geometry to obtain a localized image. The outer contour formed by the conductor sections is geometrically configured such that the width of the surface coil changes over its length. Thus, the coil can be positioned to conform to both an area and position which allow every segment of the localized area of interest of the examination subject to be examined with optimal signal-to-noise ratio. Further, a transmission coil which encompasses the conductor section is capable of transmitting localized radio-frequency signals, thus, eliminating the need for the use of a whole-body resonator for imaging localized areas of interest.
Abstract:
A surface coil for a nuclear magnetic resonance apparatus has a number of conductor sections arranged relative to each other. Switches are provided to connect the conductor sections in different combinations. Each combination outlines a differently sized area, or a different region, of the patient. The switches also connect the combination of conductor sections which is to be utilized to a tuning circuit. A single surface coil can thus be used to examine different regions of a patient without the coil having to be physically displaced. The different combinations of conductor sections, which connected, may form a rectangle which is adjacent to, or overlaps, a rectangle of unconnected sections.
Abstract:
A surface resonator for use in nuclear magnetic resonance tomography is a single turn loop of ribbon-like electrical conductor having spaced ends facing each other which form a capacitor whose capacitance determines the resonant frequency. The loop of ribbon-like conductor is shaped to conform substantially to the generated surface of a truncated cone. The ends of the loop may be in the form of spaced plates for providing the necessary capacitance, or may be connected by one or more discrete component capacitors.
Abstract:
An apparatus for generating a substantially homogeneous magnetic high-frequency field and/or for receiving high-frequency signals in a nuclear magnetic resonance apparatus, such as zeugmatography. The apparatus contains at least two conductor sections of predetermined length which extend on a least one imaginary cylindrical surface parallel to the axial direction of the cylindrical surface. The conductor sections are adapted to carry current in opposite directions when connected to either external feeding or external receiving devices. In one embodiment, the arrangement operates at frequencies of illustratively 20 MHz so as to provide an improved signal-to-noise ratio over prior art systems. An envelope formed of electrically conductive material is adapted to be impervious to high-frequency energy, but permeable to low-frequency energy, and further adapted to be concentrically arranged with respect to the imaginary cylindrical surface about the conductor sections. The ends of the conductor sections which are arranged distal to the energy or receiving devices are terminated by means which reflect waves of high-frequency energy to produce in-phase high-frequency fields.