Abstract: Each of image signals representing radiation images of a single object is weighted with a weight factor. Signal components of the weighted image signals representing corresponding pixels in the radiation images are subtracted from each other, and a difference signal representing an image of a specific structure of the object is obtained. The weight factor is set for each pixel in each radiation image and in accordance with a difference between logarithmic values of radiation doses with respect to corresponding pixels in the radiation images, or in accordance with a logarithmic value of a ratio between the radiation doses with respect to the corresponding pixels in the radiation images.

Abstract: Methods and apparatus are provided for reducing image artifacts from a computed tomography (CT) image generated using a CT system. A plurality of projection views of an object are obtained and a plane of reconstruction including reconstructed images is defined. A smoothing function is applied to the reconstructed images to reduce image artifacts wherein a greater amount of z-smoothing is applied to images located a greater distance from an iso-center.

Abstract: An X-ray mask structure and X-ray exposure method using the same are disclosed, wherein the mask has an X-ray absorptive material pattern, a supporting film for supporting the pattern, and a holding frame for holding the supporting film, wherein a suction port is arranged to be communicated with an external gas drawing system, and wherein a supply port is provided so that a gas can be supplied therethrough, for prevention of dust adhesion to the mask.

Abstract: A breast cup is described herein which is made from a stretchable material for compressing the breast during x-ray imaging. The breast cup is constructed preferably of a fabric having elastomeric yarns to allow it to be easily worn during radiation and afterwards removed with minimal effort. The stretchable qualities provide the needed compression throughout the cup, yet is not unduly uncomfortable while worn.

Abstract: X-ray apparatus has a d.c.-a.c. converter circuit supplied with energy that is connected via a line connection to a high-voltage transformer supplying the high-frequency operating voltage to an X-ray tube. The line connection has a first and a second conductors that are insulated from one another and are disposed close to one another for achieving a low line inductance. These conductors have ratio of radius to conductor thickness such that a low ohmic impedance is established.

Abstract: A scattered ray absorption grid enhancing a scattered ray absorption property without increasing costs is provided. A grid portion of the scattered ray absorption grid is constituted by use of plate members obtained in such a manner that a powder containing tungsten 50% by weight or more is hardened with a binder so that the powder has a spatial filling rate of 40% or more.

Abstract: An optical encoder includes a reflective scale 1 and a sensor head 2. The sensor head 2 comprises a lead frame 21; and LED chip 22 mounted on the lead frame 21 and having a light-emitting surface directing upward for irradiating the scale 1; a photosensitive device chip 23 mounted on the lead frame 21 and having a photosensitive surface directing downward for receiving a reflected light from the scale 1; and a transparent resin body 24 molded for sealing the LED chip 22 and the photosensitive device chip 23 therein. A convex 25 is formed on a surface, which faces on the light-emitting surface of the LED chip 22, of the transparent resin body 24. A reflective film 26 is formed over the convex 25.

Abstract: A method for generating an image of an object using a computed tomography (CT) imaging system, which includes at least one x-ray detector array and at least one rotating x-ray source projecting an x-ray beam, includes the steps of identifying a physiological cycle of the object (the cycle comprising a plurality of phases); selecting at least one phase of the object; collecting at least one segment of projection data for each selected phase of the object during each rotation of each x-ray source; generating a projection data set by combining the projection data segments; generating a cross-sectional image of the entire object from the projection data set; and communicating the image or data associated with the image to a remote facility. The remote facility provides remote services over a network.

Abstract: One embodiment is a method for reconstructing at least one image representative of an object utilizing a scanning imaging system having a multislice detector array and a radiation source. The method includes helically scanning the object with the scanning imaging system to acquire a plurality of projection views of the object, including projection views acquired at different cone angles of the radiation beam; selecting a region of reconstruction (ROR) to define sets of conjugate samples in the projection views; and reconstructing at least one image of the object. The reconstruction includes weighting the sets of conjugate samples using a cone-angle dependent weighting function, and filtering and backprojecting the weighted samples.

Abstract: A method for weighting projection data is provided. The method includes helically twin beam scanning an object at a selected pitch to acquire a first data sample from a first detector row and a second data sample from a second detector row. The first data sample includes first conjugate data and first two pi data. The second data sample includes second conjugate data and second two pi data. The first conjugate data and the second conjugate data are conjugate each other, and the first two pi data and the second two pi data are two &pgr; projection angle apart. The method also includes identifying a center view of the first conjugate data and the second conjugate data, and weighting at least one of the first conjugate data, the second conjugate data, the first two pi data, and the second two pi data inverse to the identified center view.

Abstract: Scalable multislice systems which, in one embodiment, includes a scalable multislice detector, a scalable data acquisition system (SDAS), scalable scan management, control, and image reconstruction processes, and a user interface, are described. More specifically, the user interface is implemented in a host computer for defining the configuration of the imaging system. Particularly, after selection of each scan parameter, the user interface displays the available scan parameter values for the remaining parameters so that the scan objectives are met. More specifically, after selection of each scan parameter, the user interface updates the remaining scan parameters, including prospective and retrospective image thicknesses.

Abstract: A method for reconstructuring a planar image slice in a CT scanner having a predetermined reconstrunction angle and including a detector array having n rows, n being an integer greater than 1, said method comprising: acquiring X-ray attentuation data from the detector array along a predetermined portion of a helical scan path in the vicinity of an axial position corresponding to the planar image slice, wherein the predetermined portion has an angular extent that is generally equal to the reconstruction angle; and processing the data to reconstruct an image of the slice, using data acquired substantially only along the predetermined portion of the scan path.

Abstract: An improved x-ray tube cooling system is disclosed. The system utilizes a shield structure that is connected between a cathode cylinder and an x-ray tube housing and is disposed between the electron source and the target anode. The shield a plurality of cooling fins to improve overall cooling of the x-ray tube and the shield so as to extend the life of the x-ray tube and related components. When immersed in a reservoir of coolant fluid, the fins facilitate improved heat transfer by convection from the shield to the to the coolant fluid. The cooling effect achieved with the cooling fins is further augmented by a convective cooling system provided by a plurality of passageways formed within the shield, which are used to provide a fluid path to the coolant. In particular, a cooling unit takes fluid from the reservoir, cools the fluid, then circulates the cooled fluid through cooling passages. The coolant is then output from the passageway and directed over the cooling fins.

Abstract: A load port interface for determining the presence or absence of wafers in a cassette, i.e. a wafer mapper, is integrated with a port closure assembly in a load port interface separating a process environment from an operator environment. A cover plate and a door are arranged in an L-shape, with both members being able to seal the port in a bulkhead of the load port interface. In one configuration, the cover plate seals the port, while door panel members rest horizontally on the operator side of the bulkhead. In this position, a wafer stack, W, inside of a cassette may be placed on the inside door panel, with the top of the wafer stack, W, being open. As the door is raised from the horizontal position to a vertical position, the wafer stack, W, is rotated through an opening in the bulkhead so that the wafer stack, W, is now on the process side. The wafer mapper features a moveable trolley connected to, or within, the door.

Abstract: The invention described herein combines the structural digital X-ray image provided by conventional stereotactic core biopsy instruments with the additional functional metabolic gamma imaging obtained with a dedicated compact gamma imaging mini-camera. Before the procedure, the patient is injected with an appropriate radiopharmaceutical. The radiopharmaceutical uptake distribution within the breast under compression in a conventional examination table expressed by the intensity of gamma emissions is obtained for comparison (co-registration) with the digital mammography (X-ray) image. This dual modality mode of operation greatly increases the functionality of existing stereotactic biopsy devices by yielding a much smaller number of false positives than would be produced using X-ray images alone.

Abstract: A detector for detection of ionizing radiation, and an apparatus for use in planar beam radiography, including such a detector. The detector includes a chamber filled with an ionizable gas. First and second electrode arrangements are provided in the chamber with a space therebetween. The space includes a conversion volume, an electron avalanche amplification unit arranged in the chamber, and at least one arrangement of read-out elements for detection of electron avalanches. To reduce the effect of possible spark discharges in the chamber, at least one of the first and second electrode arrangements includes a resistive material having a surface facing the other electrode arrangement.

Abstract: Apparatus and assembly for and associated method of monitoring a physical property of a material, such as the specific gravity of a processed meat product of the density, and hence weight, of tobacco in a cigarette rod, comprising: means (19) arranged to direct radiation (30) into a material having a physical property to be monitored; first sensing means (23) arranged to sense levels of residual measurement radiation passing from the irradiated material and to provide respective measurement signals representative of the sensed levels of residual measurement radiation; reference means (18) which is arranged to be located in the path of the radiation (30), optionally adjacent or within the material whose physical property is to be monitored, and which has radiation absorption characteristics corresponding to predetermined low and/or high radiation absorption characteristics of the material whose physical property is to be monitored; second sensing means (22) arranged to sense levels of residual reference radiat

Abstract: In one embodiment, the present invention is a method for positioning an x-ray beam on a multi-slice detector array of an imaging system in which the detector array has rows of detector elements and is configured to detect x-rays in slices along a z-axis. The method includes steps of comparing data signals representative of x-ray intensity received from different rows of detector elements and positioning the x-ray beam in accordance with a result of the comparison.

Abstract: A DEXA bone densitometer produces estimates of future fracture risk from a current fracture data derived from a lateral image of a patient's thoracic and lumbar spine taken in a single scan, typically with the patient on her or his side, and from numerical bone mineral density measurements.

Abstract: Method and device for forming a 3D image of an object to be examined by combining at least two reconstruction images, acquired by an X-ray device, by weighted addition. Specifically, each reconstruction image is weighted with a respective weighting function which describes at least approximately the distribution of noise and/or the distribution of artifacts in the reconstruction image. The image quality of the resultant three-dimensional image is thus significantly improved.