Abstract: A universal radiation image identification system for use in an environment such as a hospital wherein an information management system is already available. The identification system is interfaced to the existing information system in order to avoid reentering the identification data with respect to radiological data. The radiological data or image typically is stored in a photostimulable phosphor screen.

Abstract: A correction system for correcting and maintaining the baseline offset signal value of a PMT channel of a scintillation detector at a predetermined value. The correction system utilizes an event driven mode wherein the correction is performed based on detected gamma interactions and this mode is utilized during periods of high count rate. Using the event driven correction mode, the system provides an output of far PMT channels based on a detected peak PMT channel. In a second mode, software driven correction, false triggers are inserted into the processing logic to initiate sampling of the baseline offset signal value and "simulate" gamma interactions. The false triggers are used by the system to perform baseline correction. The second mode is used during periods of lower count rate. Under both modes, the system effectively samples the baseline offset values from a channel that detects substantially no light energy to sample the baseline offset amount.

Abstract: The disclosed CT scanner includes a tomography system for generating data during a scan. The tomography system includes a detector characterized by at least one afterglow amplitude and at least one afterglow time constant, and a sampling device for generating a plurality of samples x.sub.i for all i from zero to MAX minus one of the detector output signal. The scanner also includes a set of N sub-processors for processing the samples x.sub.i, each of the sub-processors being represented by a unique integer q selected from zero to N minus one and receiving only the samples X.sub.iN+q. Each sub-processor includes a device for generating a compensated signal according to a function of at least a portion of the received samples and parameters representative of the afterglow amplitude and the afterglow time constant.

Abstract: An apparatus and method is provided for maximizing the number of digital radiological images displayed on a display screen. Digital radiological frames, including radiological images and non-image portions, produced by a computed tomography device, a magnetic resonance imaging device, an ultrasound device or other radiological equipment are first stored. The radiological image portion of the frames are then identified and the non-image portion of the frames are reduced, producing a modified radiological frames. Finally, the modified radiological frames are arranged relative to one another in an area corresponding to the area of a display screen and displayed on a display screen.

Abstract: The invention provides a back-projection image reconstruction method or algorithm of the type B(FB).sup.-1 g=c, where c is the image data vector which is to be reconstructed, g is, arranged in suitable form, the measurement data vector from which the image data vector c is to be reconstructed, F is a matrix representing the forward operation from c to g and B is a matrix representing the corresponding direct back-projection operation, characterised in that for the matrix (FB).sup.-1 there is substituted the equivalent, computationally more amenable, matrix product WQ.sup.-1 W*, wherein W* is the complex conjugate of W, Q.sup.-1 is the inverse of a matrix Q obtainable from the matrix FB by the operation Q=W*(FB)W and W is a matrix related to the Fourier Transform and defined in the specification.

Abstract: The present invention relates to a method of determining physical and/or chemical properties in water samples containing suspended substances and/or particles, the physical and/or chemical properties being singly or jointly determined as amount of nitrate, iron, ammonium, phosphate, total nitrogen or total phosphorous; turbidity, chemical oxygen demand (COD) and/or biological oxygen demand (BOD).

Abstract: A method for X-ray computed tomography includes a process for rotating around an object an X-ray source for applying a cone-beam X ray and a scanner having a two-dimensional X-ray detector mounted thereon for deriving projection data and a process for preparing a geometric distortion correction table for correcting an image geometric distortion of the two-dimensional X-ray detector for the projection data, for reconstructing a distribution of X-ray attenuation coefficients of the object from said corrected projection data.

Abstract: A method and system for correlating accuracy of computer tomography (CT) image resolution is described. Small radio-opaque markers having a diameter less than one slice width of a CT scan are embedded in the object, such as a bony skeletal member, to be measured, the object is then CT scanned so that the radio-opaque markers appear in at two slices of the scan. The markers are also physically located by detecting them with a sensor, such as a positioning pointer. Also described is one form of marker comprising a tantalum sphere mounted in a ceramic, preferably alumina, pin.

Abstract: Radiation images of a single object are formed respectively with radiation having different energy distributions, and image signals respectively representing the radiation images are obtained. An unsharp mask signal Lu corresponding to super-low frequency is calculated from one of the image signals or from an image signal, which represents the mean-level image of the radiation images and is calculated from the image signals. The values of parameters for a subtraction process are changed in accordance with the unsharp mask signal Lu. The image signal components of the image signals are subtracted from one another, which image signal components represent corresponding picture elements in the radiation images, with the value of each of the parameters being thus changed for different picture elements in each of the radiation images.

Abstract: A four-layer neural network is trained with data of midinfrared absorption by nerve and blister agent compounds (and simulants of this chemical group) in a standoff detection application. Known infrared absorption spectra by these analyte compounds and their computed first derivative are scaled and then transformed into binary or decimal arrays for network training by a backward-error-propagation (BEP) algorithm with gradient descent paradigm. The neural network transfer function gain and learning rate are adjusted on occasion per training session so that a global minimum in final epoch convergence is attained. Three successful neural network filters have been built around an architecture design containing: (1) an input layer of 350 neurons, one neuron per absorption intensity spanning 700.ltoreq..nu..ltoreq.1400 wavenumbers with resolution .DELTA..nu.

Abstract: A portable and preferably hand-held X-ray generator for use in intraoral and other X-ray applications, and a new process of dental image acquisition which utilizes a novel receptor holder physically linked to the lightweight, portable generator, and a unique, articulating arm and cradle which allows one generator to be used in multiple operatories. The system's generator has a reduced X-ray output and much smaller focal spot area than conventional dental X-ray generators, which reduces the X-ray output and the overall patient X-ray burden. The smaller focal spot also allows for improved resolution in the final image.

Abstract: A device for treating cerebral lesions by gamma radiation, comprising an approximately semi-spherical source-collimator assembly having a large number of gamma ray sources associated with channels directed to the same focal point. Each gamma ray source is associated with a group of channels arranged in the manner of a cone, the apex of which is at the focal point.

Abstract: A method for forward projecting data from an image volume to a projection plane is described. In one embodiment, the method includes the steps of rotating the image data by a transaxial angle .phi. to align the image data with the projection plane. Then, for every axial angle .crclbar., and for each y'.sub.0 and for each value v in the projection plane:(a) determining z'.sub.0 =(v-y'.sub.0 sin .crclbar.)/ cos.crclbar. and interpolating in the z' direction for each x', to form the line I(x', y'.sub.0, z'.sub.0); and(b) interpolating I(x', y'.sub.0, z'.sub.0) for each value of u.

Abstract: A two-dimensional radiation detector (30) receives divergent ray penetrating radiation along conical or pyramidal ray paths which converge at an apex. The radiation may emanate from one or both of an x-ray tube (16) or radionuclei injected into a human subject. As the radiation detector rotates around the subject, it is repeatedly sampled to generate two-dimensional data sets h.sub.t (u,v) at each of a plurality of samplings t. Each two-dimensional data array is weighted (44) and divided into two components. A first component processor (48) convolves a first component of each two-dimensional array with respect to u for each v. A second component processor (50) processes a second component of each two-dimensional array (FIG. 6) including weighting each component with a geometrically dependent weighting function W from a weighting function computer (46). The processed first and second components are combined (52) and backprojected (54).

Abstract: A recording device, comprising a probe electrode, a recording medium having electric memory effect and a writing voltage applying unit for applying voltage onto the recording medium from the probe electrode, and a reproducing device comprising a probe electrode, a recording medium exhibiting electric memory effect or a recording medium recorded by energy irradiation, a voltage applying unit for applying voltage not exceeding the threshold value voltage giving rise to electric memory effect onto the recording medium from the probe electrode and a reading unit for reading the change in current quantity passing through the recording medium.

Abstract: A method of processing images in order automatically to detect key pixels (K.sub.2, K.sub.3, K.sub.4) situated on the contour of an object (LV) in an initial image (I.sub.0), and a device for implementing this method in which there is storage, in the digitized initial image (I.sub.0), of the intensity of the pixels [A.sub.0 (x,y)] and of data of regions of the object (LV), classes (C.sub.1 C.sub.m); selection of pixels of interest (PI), on the contour, inside and outside the object (LV); generation of characteristics (E.sub.1 E.sub.k) for each of the pixels of interest (PI); classification of the pixels of interest (PI) into the classes (C.sub.1 C.sub.m); and selection of the key pixels (K.sub.2, K.sub.3, K.sub.4) from corresponding classes (C.sub.2, C.sub.3, C.sub.4).

Abstract: An x-ray diagnostic installation has an x-ray source for generating an x-ray beam, an x-ray image converter for acquiring an x-ray image that includes a scintillator layer and a detector with photoelements arranged matrix-like, and a playback system connected thereto for the playback of the x-ray image. The x-ray image converter also includes an array of a number of optical elements arranged between the scintillator layer and the image converter. This array can be composed of micro-lenses or micro-objectives lens elements. A respective micro-lens is allocated to each photoelement of the detector or a respective micro-objective lens elements is allocated to a group of photoelements of the detector.

Abstract: A method of detecting and identifying abnormal regions in living tissue depicted in a digital radiograph includes, in each of a number of stages, identifying an abnormal region; and reducing any overlap between the identified regions. Typically the digital radiograph is a mammogram and the abnormal regions are suspicious mass regions in a human breast. Five stages of identifying are used to detect a region with a global minimum in the smoothed image; a region with a local minimum in the original image; a region with a local minimum in the filtered image; a small region of rounded shape and low contrast; and a region of rounded shape and high contrast.

Abstract: A method and apparatus for the rapid estimation of the gas concentration within the headspace of a production beverage container which contains a carbonated beverage, includes preparing a prediction model based on correlations between an infrared absorption spectrum obtained from an analysis container and corresponding measured values of gas concentrations and physical properties of the analysis container, the method, whereby the physical property or gas concentration within the headspace of production container do not need to be measured directly, but rather are estimated based on the prediction model with a measured infrared absorption spectrum as an input to the prediction model, thereby providing non-invasive monitoring of production containers, filled and pressurized.

Abstract: The invention relates to a device for measuring the momentum transfer spectrum of X-ray quanta elastically scattered in an examination zone, comprising an X-ray source and a detector device with a plurality of detector elements, one of which serves to measure a reference radiation beam. Attractive results are obtained in that between the examination zone and the X-ray source there is arranged at least one scatter member which scatters the X-rays emitted by the X-ray source, the reference radiation beam being formed from the part of the scattered radiation which reaches the reference detector element rectilinearly through the examination zone.