Abstract: Each of the detectors of a detector inventory are subjected to an identical flat field exposure to generate a radiation mage in each of the detectors, from the radiation images the overall field distribution is determined and neutralized in the images, next the sensitivity is determined.

Abstract: Each of the detectors of the inventory are subjected to an identical flat field exposure to generate a radiation mage in each of the detectors, from the radiation images the overall field distribution is determined and neutralized in the images, next the non-uniformity is calculated.

Abstract: A system and method for embedding in a phantom target used in digital radiography systems information specific to the phantom target, such as serial number, phantom target type, precision landmarks, composition, physical properties of the dedicated targets and the like. The information is encoded and represented by small holes in the phantom target that can easily and unambiguously be detected by decoding-software acting on the radiation image of the phantom target. A look-up table or any other flexible data structure defines the functionality of the holes detected based on their image-location. Regions of interest can be located based on an internal coordinate system defined accurately by the sub-pixel position of the hole centres.

Abstract: An apparatus and method for an X-ray dosimeter support, comprises of a material-poor support-layer, held by a frame elevated by at least one foot, comprising optimization for low back-scatter, high measurement-repeatability and ease of assembly and disassembly.

Abstract: Each of the detectors of a detector inventory are subjected to an identical flat field exposure to generate a radiation mage in each of the detectors, from the radiation images the overall field distribution is determined and neutralized in the images, next the sensitivity is determined.

Abstract: A method for neutralizing the non-noise correlated, multiplicative image-artifacts introduced by the X-ray exposure, the detector or the digitizer prior to the determination of the Signal-to-Noise Ratio or the (Normalized) Noise Power Spectrum in CR/DR radiography systems. This method uses statistical techniques and the photon-noise physical model to correct the raw, digital image-data obtained in the selected region of interest (roi) for evaluation during quality control (QC).

Abstract: Each of the detectors of the inventory are subjected to an identical flat field exposure to generate a radiation mage in each of said detectors, from the radiation images the overall field distribution is determined and neutralized in the images, next the non-uniformity is calculated.

Abstract: A method for canceling the impact of the physical property variability on the image quality performance of a digital imaging system, obtained during quality control (QC) analysis using a serial numbered quality control (QC) target by applying physical property deviation controlled behaviour model corrections to the raw image quality performance. The serial numbered QC-target used for the QC analysis comprises target-specific, measured physical property data encoded in- or outside of QC-target.

Abstract: A method for generating an output image by reducing the size of an input image by determining for a pixel location (i,j) in the output image a corresponding areaxy in the input image, fetching the input image areaxy pixel values, calculating an output pixel value Dij for the pixel location (i,j) using a size reducing algorithm, inserting Dij in the output image and repeating the previous steps for each pixel location (i,j) in the output image. The value Di,j is obtained by adding to the lower resolution background representation A of the input image area pixel values with a value obtained by amplifying MED, representing the pixel value in the input image area that most deviates from said lower resolution background representation A, by means of a significance factor SF.

Abstract: A contrast phantom for assessing the characteristic, exposure-related signal and noise response and dynamic range of an image recording and detection system. The contrast phantom is composed of an absorber medium having a sudden K-edge absorption change of the mass attenuation coefficient for at least one photon energy level in-between the mean and maximum energies of the lowest energy spectrum it is subjected to. The invention further provides a method for assessing the characteristic, exposure-related signal and noise response and dynamic range of an image recording and detection system with the aforementioned contrast phantom.

Abstract: An edge phantom for assessing the sharpness response of a radiation image recording and detection system wherein the edge phantom is subjected to radiation emitted by a source of radiation to generate a radiation image and wherein the radiation image, recorded and detected by the system, is evaluated. The design of the edge phantom provides that any line outside a plane perpendicular to the edge phantom's top face, connecting the focus of the source of radiation with a point on a curved or flat lateral face of the phantom used for sharpness analysis coincides with a line part of that lateral face containing that point.

Abstract: A photostimulable phosphor screen including a photostimulable phosphor and a transparent outermost layer with a thickness, d, larger than 150 &mgr;m for providing enhanced sharpness of an image obtained in portions with a higher spatial frequency than 2 line pairs per mm by applying a method for reading a radiation image stored in a photostimulable storage phosphor screen with a thick transparent outermost layer when the screen is stimulated through the transparent outermost layer and the stimulated light is read through the transparent outermost layer.

Abstract: A contrast phantom for assessing the characteristic, exposure-related signal and noise response and dynamic range of an image recording and detection system. The contrast phantom is composed of an absorber medium having a sudden K-edge absorption change of the mass attenuation coefficient for at least one photon energy level in-between the mean and maximum energies of the lowest energy spectrum it is subjected to.

Abstract: An edge phantom for assessing the sharpness response of a radiation image recording and detection system wherein the edge phantom is subjected to radiation emitted by a source of radiation to generate a radiation image and wherein the radiation image, recorded and detected by the system, is evaluated. The design of the edge phantom provides that any line outside a plane perpendicular to the edge phantom's top face, connecting the focus of the source of radiation with a point on a curved or flat lateral face of the phantom used for sharpness analysis coincides with a line part of that lateral face containing that point.

Abstract: A light guide comprising an entrance window, an output window and a multiplicity of light channels for transmitting light falling onto the entrance window towards the output window by internal reflection, wherein the light channel consists of light guiding core material which is enclosed in a cladding gas having a refractive index that is lower that the refractive index of the core material.

Abstract: A light guide comprising an entrance window, an output window and a multiplicity of light channels for transmitting light falling onto the entrance window towards the output window by internal reflection, wherein the light channel consists of light guiding core material which is enclosed in a cladding gas having a refractive index that is lower that the refractive index of the core material.

Abstract: A compact apparatus for reading a radiation image that has been stored in a photostimulable phosphor screen comprises an array of transducer elements, e.g. avalanche photodiodes, and electronic circuitry for integrating the signal of each of the transducer elements that are illuminated by the light emitted by a pixel of the screen upon stimulation of that pixel.

Abstract: A photostimulable phosphor screen comprising a photostimulable phosphor and a transparent outermost layer with a thickness, d, larger than 150 &mgr;m.

Abstract: A method is disclosed for the reduction of vibrations in a system using a stepping motor, driving parts at a constant velocity. On a test rig, the dynamic behaviour of the stepping motor in micro stepping mode is measured by a system comprising a rotation encoder. The measured data are filtered and used to compensate the unwanted speed fluctuations. In a first method, compensation is done by modification of the theoretical current-vector angles of basic micro stepping, while keeping the current-vector length constant. In a second method, first the current-vector angles are optimized, where after the current-vector lengths are optimized to correct the stepping motor for a wide range of speeds and load torques. In both methods, the stepping frequency is constant over all steps and determined by the desired angular speed of the stepping motor.