Abstract:
An electron source for an X-ray scanner comprises an emitter support block, an electron-emitting region formed on the support block and arranged to emit electrons, an electrical connector arranged to connect a source of electric current to the electron-emitting region, and heating means arranged to heat the support block.
Abstract:
A monitoring detector assembly (70) is positioned outside the scanning plane of a CT scanner to insure detection of unattenuated x-rays from the x-ray source (26) of the scanner. The monitoring detector assembly preferably provides a sequence of monitor detection measurements simultaneous with the sequential acquisition of the image data from the image detectors (28) during each projection of the scan by a filtered CT scanner. The image data are monitored using the closest in time monitor detection measurement.
Abstract:
An X-ray examination apparatus according to the invention comprises a filter for limiting the dynamic range of an X-ray image formed on an X-ray detector by irradiation of an object, for example a patient to be examined, by means of X-rays. The filter comprises a number of electrodes and grains or powder particles containing an X-ray absorbing material and suspended in a suspension liquid. When a voltage is applied to electrodes, X-ray absorbing material in the suspension will move to the excited electrodes under the influence of electrophoresis. A distribution with a desired X-ray absorption profile is adjusted by application of a suitable voltage pattern. The electrodes may have dimensions of, for example 0.5 x 0.5 mm, enabling an X-ray absorption profile to be obtained with a high spatial resolution. The X-ray absorption profile can be changed within a brief period of time, for example within one second, by changing the voltage pattern on the electrodes.
Abstract:
A slit radiography device scans a body under examination with a fan shaped X-ray beam. A number of absorption elements placed next to each other can be moved into the X-ray beam to a greater or lesser extent in order to influence the X-ray radiation incident on the body per sector of the X-ray beam. As seen in the longitudinal direction of the slit the absorption elements are designed such that a certain distance is present between them. As seen in the direction of the X-ray radiation the thickness of the material of the absorption elements is always the same, i.e. there are no gaps between the absorption elements that the X-ray radiation can shine through.
Abstract:
An X-ray tomograph which extracts data corresponding to the transmission data of parallel beam X-rays from X-ray transmission data collected on the basis of fan beam X-rays and reconstructs an image on the basis of the extracted data, wherein shower-like artifact occurring in the reconstructed image due to the influence of an instantaneous change in the X-ray intensity is eliminated, characterized by storing a plurality of views of output data from a data collection unit in a buffer memory, calculating the weighted average on the data of a plurality of views stored in the buffer memory to obtain view data free from the influences of the X-ray intensity change, and replacing the view data affected by the X-ray intensity change by this view data.
Abstract:
An imaging system (100) includes a radiation source (110) with a focal spot (204) that emits a beam of x-ray photons that traverses an examination region (106). The imaging system further includes a photon counting detector array (122) that detects a sub-set of the x-ray photons that traverse an examination region. The imaging system further includes a controller (116) that generates and transmits a pause signal, in response to a calculated drop in an intensity of the emitted the beam of x-ray photons below a predetermined intensity level, which causes the photon counting detector array to pause detecting the sub-set of the x-ray photons. The imaging system further includes a counter (136) that counts, for each of a plurality of counting periods, the x-ray photons of the sub-set detected by the photon counting detector array in the corresponding counting period.
Abstract:
A short-form image intensifier is made possible by an image correction circuit receiving distorted digital image signals from the image intensifier and operating on them with a reverse distortion function. The resulting correction of distortion makes possible the short form of the image intensifier which would otherwise be expected to produce unacceptable distortion.
Abstract:
In a process for the automatic radioscopic quality control of foodstuff items (104), an item (104) to be controlled is taken past an X-radiation source (100) and the X-radiation (100a-100c) passing through said item (104) to be controlled is detected. A chargeimage is generated from the detected X-radiation (100a-100c) by means of a sensor (108) having a plurality of sensor units (102a-102c) by shifting generated charges (110, 112, 114) over several sensor units (102a-102c) synchronously with a direction (106) and speed of movement of the item (104) to be controlled and imaged on the sensor (108) and by adding the partial charges generated by the sensor units (102a-102c) to the charge image. The foodstuff item to be controlled is then assessed by means of the charge image.
Abstract:
An image pick-up apparatus (1) which includes an image sensor (2) is provided with a control circuit (4) arranged to read out the image sensor with a given delay after the picking up of a light image. Incident light is prevented from disturbing an image picked up during read-out in that reading out commences after the light intensity of the light image has vanished. Notably the disturbing of the picked-up image during read-out due to afterglow of a phosphor layer (25) on which the light image is formed is conteracted.
Abstract:
The apparatus for making X-ray images comprises a luminescent screen (2), like a phosphor screen, arranged to provide a visible image by the effect of X-rays sent out by an X-ray source and a CCD camera (3) for receiving and storing the image forming on the luminescent screen (2). The apparatus further comprises, in optical communication with the luminescent screen and separate from the CCD camera, a photosensor (6) which is connected to computing and control means which are connectable in signal transfer comunication with the control means (14) of the X-ray source for adjusting a correct quantity of exposure.