Abstract:
Apparatus and methods for providing a distance indication using an x-ray apparatus. According to various embodiments, an x-ray apparatus may be provided comprising an x-ray generator and a visible light generator. The apparatus may further comprise a projection member, such as a reticle, comprising a material at least partially transparent to visible light, wherein the projection member comprises an image positioned within the path of the visible light so as to project a secondary image comprising a shadow defined by the image. A LASER configured to deliver a LASER beam at an angle relative to the visible light may be provided such that the LASER beam intersects at least a portion of the secondary image at a predetermined distance from the LASER to allow a user to determine precisely a distance from the apparatus to an object to be exposed to x-ray radiation.
Abstract:
Systems and methods for making and using a multi-blade collimator device are described herein. The collimator device can include a base member, a rotational member, and multiple X- ray-attenuating blades that fit together to define an aperture. The blades are typically disposed between the base member and rotational member. Additionally, the blades can be mechanically connected to or interfaced with the base member and the rotational member so that when the rotational member is rotated with respect to the base member, the blades move and cause the aperture to change in size. The aperture can be any shape, including polygonal, square, or rectangular. While the aperture's size can be increased and decreased, the shape and orientation of the aperture can remain substantially constant. The collimator can contain a single layer of blades or multiple layers of blades. Other embodiments are described.
Abstract:
A multi-leaf collimator for radiation therapy in which the position of the leaves (10; 10 - 1...10 - 20) are determined by measuring a magnetic field allows determine the leaf position with enhanced precision, and is at the same time robust to perturbations or disturbances. The magnetic sensor (12, 14) may comprise a magnetic encoder (14) that varies in a predefined pattern along a lengthwise direction of the magnetic element (12), in particular according to step function.
Abstract:
Es wird ein Filter (14) angegeben, durch den eine verbesserte Anwendbarkeit eines Computertomographen (1) für die Durchführung einer Kontrastmittel-verstärkten Strahlentherapie erzielt wird. Der in den Strahlengang zwischen einer Strahlenquelle (4) und einer isozentrischen Achse (I) des Computertomographen (1) einsetzbare Filter (14) ist bezüglich eines innerhalb seiner Filterfläche (A) ortsabhängig variierenden Strahlungsdurchlasskoeffizienten (ß) für die Röntgenstrahlung des Computertomographen (1) derart dimensioniert oder dimensionierbar, dass bei umlaufender Bestrahlung eines Standardobjekts (13') vorgegebener Geometrie und Röntgenabsorption durch den Filter (14) die über den Querschnitt des Standardobjekts (13') deponierte Röntgendosis (D) im Wesentlichen konstant ist.
Abstract:
A multi-leaf collimator for a radiotherapy apparatus comprises a plurality of elongate leaves mounted in a carriage, the carriage being mounted on a substrate, wherein the leaves are independently moveable relative to the carriage in a longitudinal direction, and the carriage is moveable in that direction relative to the substrate, and a control apparatus arranged to receive a signal representing leaf positions relative to the substrate and being arranged to control the leaf positions relative to the carriage and the carriage positions relative to the substrate so as to achieve those leaf positions relative to the substrate. By allowing the carriage to be driven concurrently with the leaves, the speed of movement of the carriage can be added to that of the leaves. In this way, where leaves are required to make a long traverse they can do so more quickly. Most MLCs have a means for sensing the current positions of the leaves relative to the substrate, such as an optical or mechanical positional feedback system. The control apparatus can therefore compare the current leaf positions to the signalled leaf positions, and move the leaves and the carriage accordingly. Each leaf can be moved according to a difference between the current leaf position and the signalled leaf position, and the carriage can be moved according to an average difference between the current leaf positions and the signalled leaf positions. A corresponding method is also disclosed.
Abstract:
A multi-leaf collimator includes a number of independently adjustable leaves. Adjacent leaves overlap to prevent an incident beam of radiation from passing through a gap between them. The overlapping portions of the leaves are made of a first material, while the non-overlapping portions of the leaves are made of a second, different material.
Abstract:
A method and apparatus for an x-ray apparatus. The x-ray apparatus comprises a vacuum tube. A cathode is located in the vacuum tube and capable of emitting electrons. A rotatable magnetic anode located in the vacuum tube, capable of being rotated by a motor located outside of the vacuum tube, and capable of generating an x-ray beam in response to receiving the electrons emitted by the cathode.
Abstract:
Die Erfindung betrifft einen Chopper für einen Teilchenstrahl, umfassend ein ringförmiges Führungselement (11) und ein Steuerelement (13) für die Intensität des Teilchenstrahls. Erfindungsgemäß ist das Steuerelement derart gegen das Führungselement gelagert, dass mindestens ein Aufpunkt auf dem Steuerelement entlang eines Umfangs des Führungselements umzulaufen vermag. Die Lagerung entlang eines Umfangs vermag bei gleicher Lagerkraft wesentlich größere Störmomente zu kompensieren als eine Lagerung an der Drehachse. Es wird auch die Drehachse insgesamt entbehrlich, so dass das Steuerelement beispielsweise als Ring ausgebildet sein kann. Gegenüber Chopperrädern gemäß Stand der Technik bewirkt dies eine erhebliche Gewichtsersparnis, die im Ergebnis größere Umfangsgeschwindigkeiten und damit größere Modulationsfrequenzen für den Teilchenstrahl bei gleichzeitig erhöhter Betriebssicherheit ermöglicht.
Abstract:
An apparatus and method for coupling a fixed-aperture collimator to a variable-aperture collimator. The variable-aperture collimator may be an IRIS collimator having multiple leaves configured to open and close an aperture of the IRIS collimator within which the fixed-aperture collimator is retained.