摘要:
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.
摘要:
Method of removing the spatial response signature of a detector from a computed radiography image by adaptively filtering and spatially warping the characteristic response signature of the detector prior to demodulation.
摘要:
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.
摘要:
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.
摘要:
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).
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
Method of removing the spatial response signature of a detector from a computed radiography image by adaptively filtering and spatially warping the characteristic response signature of the detector prior to demodulation.
摘要:
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.