60 results about "X-ray filter" patented technology

An apparatus for use in a radiation procedure includes a radiation filter having a first portion and a second portion, the first and the second portions forming a layer for filtering radiation impinging thereon, wherein the first portion is made from a first material having a first x-ray filtering characteristic, and the second portion is made from a second material having a second x-ray filtering characteristic. An apparatus for use in a radiation procedure includes a first target material, a second target material, and an accelerator for accelerating particles towards the first target material and the second target material to generate x-rays at a first energy level and a second energy level, respectively.

A bowtie filter is constructed to have a fluidic envelope filled with attenuating fluid and a displacement insert that can present various x-ray attenuation profiles during a scan. The insert is designed to displace the attenuating fluid to achieve a denied attenuating or filtering profile. The insert can be rotated, twisted, moved, and otherwise contorted within the fluidic envelope as needed during the course of a scan. As the angle, position and shape of the zombie is changed, the x-ray profile of the filter changes. The insert may have a default shape when at rest, but can have its shape changed when external forces are placed thereon. As x-ray filtering needs change during the course of the scan, the insert can be compressed, stretched, and / or contorted to achieve additional filtering profiles.

This invention relates to an optically coupled digital radiography method and apparatus for simultaneously obtaining two distinct images of the same subject, each of which represents a different x-ray energy spectrum. The two images may be combined in various ways such that anatomical features may be separated from one another to provide a clearer view of those features or of underlying structures. The two different images are obtained using a pair of scintillators separated by an x-ray filter that attenuates part of the x-ray spectrum of an x-ray exposure such that the first and second scintillators receive a different energy spectrum of the same x-ray exposure. Alternatively, the two different images can be obtained without a filter and with two scintillators made of different fluorescing materials that react differently to the same x-ray exposure.

Tomography or X-ray CT fluoroscopy reduced in exposure to radiation in an X-ray CT apparatus or an X-ray CT fluoroscopic apparatus is to be substantialized. A channel-direction X-ray collimator or a beam forming X-ray filter is positionally controlled in the channel direction to carry out X-ray data acquisition while irradiation with X-rays limited to only the region of interest. Either the profile area of the whole subject is obtained or the profile area of the whole subject is predicted from views or scout images of irradiation of the whole subject out of X-ray projection data. Image reconstruction of views not irradiating the whole subject out of the collected X-ray projection data is carried out by predicting lacking parts from the profile area of the whole subject and making corrections accordingly. It is thereby made possible to irradiate only the region of interest with X-rays to reduce the exposure of the subject of tomography by the X-ray CT apparatus to X-rays or the exposure the subject to X-rays and the exposure of the operator's hands to radiation at the time of puncturing in X-ray CT fluoroscopy.

A filter assembly for a computed tomographic imaging system includes first and second endplates at opposite ends of the filter assembly. Also provided is a first moveable subassembly that includes at least a first x-ray filter and which is configured to move along an axis perpendicular to the first endplate between the first the second endplates. A second moveable subassembly is also provided that includes at least a second x-ray filter. The second moveable subassembly is configured to move along an axis perpendicular to the second endplate between the first and second endplates. The first moveable subassembly and the second moveable subassembly are independently movable to provide at least a small bowtie x-ray filter, a large bowtie x-ray filter, a medium bowtie x-ray filter, a flat filter, and a closed position for a radiation source positioned in a fixed position relative to the filter assembly.

An x-ray reflector may include: a substrate; a first layer formed on the substrate, the first layer including a relatively higher-Z material, where Z represents the atomic number; and a second layer formed on the first layer, the second layer including a relatively lower-Z material; at least one of the first layer and the second layer exhibiting a taper in an axial direction extending between a first end of the substrate and a second end of the substrate.

In an X-ray CT apparatus including an X-ray area detector that has a matrix structure and is represented by a multi-array X-ray detector or a flat-panel X-ray detector, radiographic conditions (protocols) for imaging of each position represented by a z-coordinate are optimized in relation to an X-ray cone beam that spreads in a z direction. A slice thickness of a tomographic image is freely controlled in the z direction using a z filter during a conventional scan or a cine scan. For each tomographic image, a reconstruction function, an image filter, a scan field, a tomographic-image tilt angle, and a position of a tomographic image are freely adjusted or independently designated for scanning of each position in the z direction. Thus, a tomographic image is reconstructed. Moreover, the position of a beam formation X-ray filter in the z direction is shifted in order to optimize a patient dose that depends on the size of the scan field, and X-ray quality.

The invention relates to x-ray filters in a collimator for controlling the energy of an x-ray beam along a projection axis in computed tomography systems. According to the invention, the filter assembly comprises a filter element for attenuating the x-ray beam, and at least a support plate which fixes the filter element. The filter element and the support plate are notch-shaped in the center part of the filter assembly along a direction perpendicular to the projection axis. The design may free space to be used by other collimator parts and further allows use of more than one filter element in a filter assembly for backup purposes. This simplifies replacement of a defective x-ray filter in the field.

A computed tomography apparatus and a method for controlling the same are provided. The apparatus is capable of switching between a high energy mode and a low energy mode at a high speed using a filter that rotates at a high speed. The computed tomography apparatus includes an X-ray generator which generates and irradiates X-rays toward a subject, an X-ray filter which includes at least one filter member, a driver which rotates the X-ray filter such that the filter members are selectively disposed in an irradiation path of X-rays generated by the X-ray generator, a detector which detects the X-rays that are transmitted to the subject, and a host apparatus which obtains X-ray images by using detected X-rays, separates the obtained X-ray images based on filter members to which the corresponding X-rays are transmitted, and reconstructs the images by using X-ray images of the identical filter member.

The adaptive X-ray filter (1) has a primary chamber that is provided with magneto-rheological or electro-rheological liquid. A secondary chamber is provided with X-ray radiation-absorbing liquid. A flexible membrane is provided to separate the primary chamber from the secondary chamber. The film thickness ratio of the liquids is variable. A heating device is located to heat the X-ray radiation-absorbing liquid. The X-ray radiation-absorbing liquid is a liquid metal.