Abstract: Systems and methods are provided for offset correction of images from a flat panel detector. In some embodiments, the apparatus and method develops one or more offset maps, acquired during system idle, for the imaging system at a plurality of exposure windows. In some embodiments, exposure parameters acquired for the imaging system before image acquisition are used to select an offset map to subtract from subsequent X-ray images. In some further embodiments, executable instructions are disclosed for directing a processor to compile one or more offset map and exposure parameters to subtract based on a selected offset map noise elements from X-ray images and thereby minimizing the time between image acquisition and display of processed images.

Abstract: The non-destructive test of a structure (10) such as an aircraft fuselage is done by placing an X-ray source (16) on one side of the structure, and placing a digital camera (24) on the other side. The microcomputer (28) analyzes the image output by the digital camera in real time. If this image is unusable, at least one setting of the source (16) is modified immediately and a new acquisition is made without wasting any time. The adjustment can then be made manually or using a slaving system. The adjustment may relate to the wave length of the X-ray beam, the dose level or the pose time if the fault concerned is related to the gray level of the image. If a directional source is being used, the defect may also have an influence on the sharpness of the image and may be caused by an alignment problem.

Abstract: Method and apparatus for adjustment of the entrance dose of a radiology apparatus of the type containing a means of X-ray beam emission, a means of detection of the X-ray beam after it has crossed an object having to be visualized, and a means of visualization connected to the means of detection, in which the distance between the means of emission and the object is estimated and, when the distance between the means of emission and the object or the distance between the means of emission and the means of detection varies, the entrance dose is modified according to said distances in order to maintain an appreciably constant equivalent dose in the plane containing the object, the distance between the means of emission and the means of detection being known.

Abstract: In an operating method for a medical installation, in particular an x-ray installation. In activation state of the medical installation, a control and evaluation device determines, upon input of a control command, a useful image of a subject. For this purpose, the control and evaluation device receives raw image of the subject acquired by a detector in a first detector mode, and determines the useful image therefrom on the basis of correction data. In a waiting state of the medical installation, the control and evaluation device updates the correction data for the first detector mode repeatedly after the expiration of a basic time interval since the last driving of the detector. For this purpose, the control and evaluation device receives raw data acquired by the detector and uses it to update the correction data.

Abstract: A region affected by X-ray beam limiting within a fluoroscopic image is specified based on position information on beam limiting by an X-ray beam limiting device. A judgment is made as to whether the region affected superposes a first brightness measuring region (region of interest) within the X-ray fluoroscopic image, and when superposition is not judged, automatic brightness control is performed based on the first brightness measuring region. When superposition is judged, the first brightness measuring region is transformed, and automatic brightness control is performed with reference to a second automatic brightness measuring region that does not superpose the region affected.

Abstract: An X-ray examination apparatus includes an X-ray source, an X-ray detector and an exposure control system. The exposure control system is arranged to control the X-ray source so as to perform a test exposure at a low X-ray dose and to perform an X-ray exposure at a higher X-ray dose. The X-ray detector applies a control signal resulting from the test exposure to the exposure control system and the X-ray source is adjusted on the basis of this control signal. The X-ray exposure produces an X-ray image and the X-ray detector supplies an image signal representing this X-ray image. The exposure control system is arranged to adjust the X-ray detector to a low spatial resolution during the test exposure and to a high spatial resolution during the X-ray exposure. The X-ray detector preferably includes a sensor matrix having sensor elements arranged in columns and rows. The spatial resolution is adjusted by deriving the control signal and the image signal from large and small groups of sensor elements, respectively.

Abstract: The present invention relates to a system and method by which the magnitude of an interfering electrical and/or magnetic field may be sampled locally (in the X-ray detector for example) and reduced or eliminated. More specifically, embodiments comprise a system and method by which an interfering field may be sampled within the same orientation as the X-ray detector panel, and then subtracted out of each respective element sample.

Abstract: In an x-ray apparatus and method to determine the radiation dose in x-ray examinations, the x-ray apparatus has an x-ray radiator, an automatic exposure timer, and a laser range finder to detect the focus-patient separation between the x-ray radiator and a patient, and a computer device determines the necessary radiation dose using the thickness of the body part of the patient to be examined. The thickness is calculated from the acquired focus-patient distance and geometric data of the x-ray apparatus.

Abstract: An offset data calculator has a normal offset data calculation function for calculating offset data based on data obtained from an X-ray flat panel detector while no X-ray is incident in each of the modes, i.e., an entire region fluoroscopy mode, a partial region fluoroscopy mode, imaging mode, etc. and storing the data in an offset data storage device, and additionally has a function for updating, upon calculation of new offset data in any of the modes, another mode offset data stored in the offset data storage device based on the new offset data calculated. Thus, from offset data acquired in any of the plurality of modes, it is possible to obtain the latest offset data in all the modes.

Abstract: An X-ray diagnosis apparatus and method for X-ray fluoroscopy in which the apparatus includes a generator, a detector, an integrator, a comparator, and a controller. In the apparatus and method, a first X-ray for the X-ray fluoroscopy is generated intermittently. A transmission X-ray transmitted through an object of the X-ray fluoroscopy is detected. X-ray transmission data obtained in a period of intermittent generation of the first X-ray is integrated and compared to a reference value. In response to the integrated X-ray transmission data reaching the reference value during the period of intermittent generation, intermittent generation of the first X-ray is disabled.

Abstract: According to a radiation imaging apparatus, any separate AEC sensor need not be prepared. Additionally, the apparatus main body can be made compact. To accomplish this, the radiation imaging apparatus has a first optical conversion element that converts incident radiation into an electrical signal, and generates image information on the basis of the electrical signal output from the first optical conversion element. Below a portion that is aligned to the gap between the first optical conversion elements, a plurality of second optical conversion elements which detect the incident amount of the radiation from the gap are formed. Exposure control for the radiation or control of the optical conversion elements is executed on the basis of the detection result by the second optical conversion element.

Abstract: An integrated digital x-ray diagnostic system and a method for conducting dental radiography which includes optimizing exposure settings based on certain physical parameters of a patient, communicating the operational status of the x-ray generator and the exposure settings directly to the a CCD sensor without radiation sensitive detector elements, and supplying various viewing stations with image data thereby improving dental office workflow. The activation of the sensor and the x-ray source are coordinated so as to avoid pre-integration of charge in the image sensor, and at the same time reduce risk of over-exposure to the patient.

Abstract: An X-ray imaging apparatus including an X-ray generation means for emitting X-rays, and an X-ray detector on which a grid selected from a plurality of different types of grids is removably mountable. The X-ray detector receives the X-rays emitted from the X-ray generation means, and obtains an X-ray image. The X-ray detector includes an automatic exposure control (AEC) detector for detecting the quantity of X-rays emitted from the X-ray generation means and for outputting a signal based on the detected quantity. The X-ray imaging apparatus also includes a control means for controlling the X-ray generation means and the AEC detector, where the control means controls the X-ray generation means based on the signal output from the AEC detector, and where the control means controls the AEC detector using correction data to correct an exposure detection element forming a part of the AEC detector.

Abstract: The invention relates to a method for performing X-ray imaging in intraoral application. The method comprises irradiation of an object with a substantially low amount of X-radiation, and a substantially low amount of X-radiation passed through the object is received. The method comprises compiling a sample of image data from the received, substantially low amount of X-radiation. The sample of image data information is communicated to an X-ray source (100), and according to the sample of image data information the object is irradiated with X-radiation, from which X-radiation the part that has passed through the object is received, and the received X-radiation, which is consistent with the sample of image data information, is used for compiling image information.

Abstract: An X-ray examination apparatus includes an X-ray source, an X-ray detector and an exposure control system. The exposure control system is arranged to control the X-ray source so as to perform a test exposure at a low X-ray dose and to perform an X-ray exposure at a higher X-ray dose. The X-ray detector applies a control signal resulting from the test exposure to the exposure control system and the X-ray source is adjusted on the basis of this control signal. The X-ray exposure produces an X-ray image and the X-ray detector supplies an image signal representing this X-ray image. The exposure control system is arranged to adjust the X-ray detector to a low spatial resolution during the test exposure and to a high spatial resolution during the X-ray exposure. The X-ray detector preferably includes a sensor matrix having sensor elements arranged in columns and rows. The spatial resolution is adjusted by deriving the control signal and the image signal from large and small groups of sensor elements, respectively.

Abstract: When a phototimer unit is used for exposure control, a deterioration in a S/N ratio occurs, and optimal exposure cannot be performed due to a deviation from a proper image sensing position and the like. Therefore, there is provided a radiation image sensing apparatus comprising an X-ray image sensing panel which is capable of non-destructive reading and adapted to sense an object image by allowing radiation from an X-ray source to pass through an object, and a control circuit adapted to perform control to stop emission of radiation from the X-ray source on the basis of a signal obtained from the X-ray image sensing panel by non-destructive reading in the image sensing operation.

Abstract: An X-ray diagnosis apparatus and method for X-ray fluoroscopy in which the apparatus includes a generator, a detector, an integrator, a comparator, and a controller. In the apparatus and method, a first X-ray for the X-ray fluoroscopy is generated intermittently. A transmission X-ray transmitted through an object of the X-ray fluoroscopy is detected. X-ray transmission data obtained in a period of intermittent generation of the first X-ray is integrated and compared to a reference value. In response to the integrated X-ray transmission data reaching the reference value during the period of intermittent generation, intermittent generation of the first X-ray is disabled.

Abstract: When X -ray irradiation is performed with many X doses and the fall of temporary sensibility or the rise of the temporary offset arises, it is the X-ray diagnostic equipment which computes the correction by sensitiveness multiplier based on the sensibility characteristic or offset characteristic of each pixel, and rectifies data. In this X-ray diagnostic equipment, the correction by sensitiveness multiplier for data correction is determined based on the signal value detected last time at least. In integrating this correction by sensitiveness value from each pixel to the output signal, the influence by the fall of temporary sensibility or the rise of the temporary offset is removed.

Abstract: X-ray camera of the present invention comprises an X-ray irradiation unit, an X-ray image sensor, a controller having a correction factor setting unit, a correction factor storage unit and a correctional operation unit, and a display unit. The X-ray image sensor in the above configuration comprises a sensor such as CCD, TFT, and the like having a scintillator on a surface thereof, and a substrate having the sensor mounted thereon. The correction factor setting unit obtains a value La/Ln by dividing a predetermined brightness reference value La set beforehand by a brightness value Ln of an arbitrary pixel “n”, and sets the obtained value as a correction factor for each pixel. The correction factor storage unit stores the correction factor set by the correction factor setting unit. The correctional operation unit obtains the correction factor from the correction factor storage unit, and performs a corrective operation.

Abstract: A radiographic apparatus capable of detecting radiation in a stable manner and in an amount suitable for a good image includes AEC detectors arranged in a stripe pattern in the space between pixels converting incident radiation into an electrical signal. The stripes of the AEC detectors are arranged so as not to be parallel to those stripes of an anti-scattering grid.

Abstract: This invention discloses a radiation imaging apparatus. According to the radiation imaging apparatus of this invention, any separate AEC sensor need not be prepared. If an AEC sensor is arranged on the radiation imaging apparatus, as in the prior art, the image quality degrades because an image sensor receives radiation that is attenuated by the AEC sensor. This can be avoided in this invention. Additionally, the apparatus main body can be made compact. To accomplish this, the radiation imaging apparatus has a first optical conversion element that converts incident radiation into an electrical signal, and generates image information on the basis of the electrical signal output from the first optical conversion element. Below a portion that is aligned to the gap between the first optical conversion elements, a plurality of second optical conversion elements which detect the incident amount of the radiation from the gap are formed.

Abstract: A region affected by X-ray beam limiting within a fluoroscopic image is specified based on position information on beam limiting by an X-ray beam limiting device. A judgment is made as to whether the region affected superposes a first brightness measuring region (region of interest) within the X-ray fluoroscopic image, and when superposition is not judged, automatic brightness control is performed based on the first brightness measuring region. When superposition is judged, the first brightness measuring region is transformed, and automatic brightness control is performed with reference to a second automatic brightness measuring region that does not superpose the region affected.

Abstract: In an X-ray diagnostics installation having an X-ray tube, an X-ray generator, a planar solid state X-ray image converter for generating X-ray images that is composed of a number of individual detectors abutting one another, an image system and having a playback device, for avoidance of the abutting locations of the individual detectors being visible in the resulting image, the amplitude of continuously changing gray scale levels at the abutting locations is locally recognized and generates a correction signal is generated corresponding to the amplitude of the gray scale levels. Based on this correction signal the gray scale levels at the abutting locations within a region.

Abstract: An X-ray diagnostic installation has an X-ray tube, a voltage generator, a planar solid state X-ray image converter for generating raw images, an image system and a playback device. The image system has a device for offset correction that acquires an offset image and stores it in a correction offset memory. The correction offset memory is preceded by a microphony detector that analyzes the current offset image for disturbances due to microphony and allows storage only of a current offset image, that is free of such disturbances.

Abstract: In a signal detecting method of repeating the processes of initiating accumulation of charge signals by switching an integrating amplifier to an accumulator mode, retaining a first electric signal outputted from the integrating amplifier immediately after switching to the accumulator mode, finding a difference as a signal component between a second electric signal outputted from the integrating amplifier immediately before switching to a reset mode after completing accumulation of the charge signals and the first electric signal, and converting and outputting the signal component into a digital signal. Here, the signal component concerning a first charge signal is retained by second signal retaining means and then converted into the digital signal. Further, the integrating amplifier is switched to the accumulator mode after completing accumulation concerning the first charge signal but before completing conversion into the digital signal to initiate accumulation concerning a second charge signal.

Abstract: The area of an irradiation region, and at least one of the area of an object region and the area of a non-object region in a radiation image obtained by radiographing an object are calculated. The effective dose of radiation from a radiation generator is acquired. An area exposure dose, the X-ray amount radiated on the object, is calculated on the basis of the area of the irradiation region, one of the area of the object region and the area of the non-object region, and an effective dose.

Abstract: An apparatus for obtaining a radiation image of an object includes a radiation image sensing unit having a plurality of photoelectric conversion elements two-dimensionally arranged in a matrix manner, and a sensor for detecting irradiation of radiation. The apparatus also includes a determining system for determining an irradiation state of radiation on the basis of an output from the sensor, and a controlling system for controlling both a start and an end of an image sensing state of the radiation image sensing unit on the basis of the determination by the determining step.

Abstract: An x-ray system that uses an x-ray source to irradiate a subject with x-rays is provided. A collimator is located proximate to the x-ray source and blocks a portion of the x-rays. A detector receives the x-rays and creates subject data indicative of a subject and collimator data indicative of a collimator. A position detector identifies a position of the collimator with respect to a field of view of the x-ray source. A gating module receives the subject and collimator data and passes at least a portion of the subject data. The gating module blocks at least a portion of the collimator data based on the position of the collimator. A display displays an x-ray image based on the portion of the subject data passed by the gating module.

Abstract: The present invention provides an image processing apparatus that constantly and efficiently obtains stable high-grade images. Sorting means sorts a target image into a first site and a second site. Extraction means and statistical-amount acquisition means extract the characteristic amounts of at least two pixels contained in at least either the first or second site and determine the statistical amount of the characteristic amounts for at least either the first or second site. Transformation means transforms pixel values based on the statistical amount. Dynamic-range compression processing is executed depending on the characteristic of the target image and in a manner optimal to the features of this image.

Abstract: An X-ray examination apparatus includes an X-ray source, an X-ray detector and an exposure control system. The exposure control system is arranged to control the X-ray source so as to perform a test exposure at a low X-ray dose and to perform an X-ray exposure at a higher X-ray dose. The X-ray detector applies a control signal resulting from the test exposure to the exposure control system and the X-ray source is adjusted on the basis of this control signal. The X-ray exposure produces an X-ray image and the X-ray detector supplies an image signal representing this X-ray image. The exposure control system is arranged to adjust the X-ray detector to a low spatial resolution during the test exposure and to a high spatial resolution during the X-ray exposure. The X-ray detector preferably includes a sensor matrix having sensor elements arranged in columns and rows. The spatial resolution is adjusted by deriving the control signal and the image signal from large and small groups of sensor elements, respectively.

Abstract: An x-ray system is provided utilizing an x-ray source and a detector to create x-ray data in a region of interest. The x-ray data comprises anatomic data, from the anatomy of a patient, and non-anatomic data, from a structure foreign to the patient. The anatomic and non-anatomic data may have non-overlapping grayscale distribution. A reject level is identified along the grayscale distribution. A processor module selects a minimum value for a transfer function based on the reject level and automatically calculates the transfer function to convert the x-ray data to display values. An x-ray image is then displayed based on the display values.

Abstract: An x-ray system that uses an x-ray source to irradiate a subject with x-rays is provided. A collimator is located proximate to the x-ray source and blocks a portion of the x-rays. A detector receives the x-rays and creates subject data indicative of a subject and collimator data indicative of a collimator. A position detector identifies a position of the collimator with respect to a field of view of the x-ray source. A gating module receives the subject and collimator data and passes at least a portion of the subject data. The gating module blocks at least a portion of the collimator data based on the position of the collimator. A display displays an x-ray image based on the portion of the subject data passed by the gating module.

Abstract: An x-ray system is provided utilizing an x-ray source and a detector to create x-ray data in a region of interest. The x-ray data comprises anatomic data, from the anatomy of a patient, and non-anatomic data, from a structure foreign to the patient. The anatomic and non-anatomic data may have non-overlapping grayscale distribution. A reject level is identified along the grayscale distribution. A processor module selects a minimum value for a transfer function based on the reject level and automatically calculates the transfer function to convert the x-ray data to display values. An x-ray image is then displayed based on the display values.

Abstract: An apparatus for obtaining a radiation image of an object includes a radiation image sensing unit having a plurality of photoelectric conversion elements two-dimensionally arranged in a matrix manner, and a sensor for detecting irradiation of radiation. The apparatus also includes a determining system for determining an irradiation state of radiation on the basis of an output from the sensor, and a controlling system for controlling both a start and an end of an image sensing state of the radiation image sensing unit on the basis of the determination by the determining step.

Abstract: An electronic video camera apparatus is provided for focusing light rays from object plane proximate image intensifier of a medical x-ray imaging system onto an image plane proximate a light sensor. The electronic video camera includes a lens system located between the object and image planes to focus light rays from the object plane onto the image plane. The light rays at the object plane are representative of a patient image. An optical filter is located between the object and image planes and partially blocks light rays passing there through. The optical filter includes at least first and second filter regions having different opacity. The first and second filter regions are alignable with the lens system at different times to block differing first and second amounts of light rays, respectively, associated with differing first and second x-ray amounts transmitted at different times.

Abstract: Method of saturation management of a digital radiographic exposure image in which there are one or more saturation areas, acquired notably after a mammogram on an acquisition chain in automatic mode using a low-dose preexposure image. A mask is made from the exposure image by taking the saturation areas into account; the coverage areas corresponding to the saturation areas of the exposure image are determined on the preexposure image by using the the mask; a digital standardization processing of the gray levels of both the exposure image and the preexposure image is then carried out; and the final image is determined from a combination of the two images thus processed.

Abstract: An X-ray image display apparatus for exposing a subject to an X-ray to obtain an X-ray image of the subject, picking up the X-ray image, converting it to a digital video signal, performing necessary signal processing on the digital video signal in an image processor to obtain X-ray image data, and displaying, on a display device, an image of a display area included in the X-ray image and specified by an input device includes a display area detector for detecting display area data representing the specified display area, and a control circuit for outputting a control signal to control a collimator drive circuit and/or a filter drive circuit on the basis of the display area data detected by the display area detector and x-ray image data supplied from the image processor, thereby controlling the position of a collimator and/or a filter so as to display the image of the display area optimally.

Abstract: An automatic exposure control for an x-ray system using a large area solid state x-ray detector (26) includes an exposure control (36, 34) arranged to generate data of interest within the data generated by the detector and to adjust the dosage of x-rays to a predetermined level in response to data of interest so that an x-ray image of a patient is generated using the predetermined level.

Abstract: A radiation detector noise reduction method includes the step of detecting incident radiation with a radiation detecting section, the radiation detecting section having a plurality of pixels arrayed in the form of a matrix, reading out the detection signal from the radiation detecting section through a readouting section, and correcting the readout detection signal with a correction section, wherein the correction step includes the first sub-step of correcting the detection signal on the basis of a first correction value corresponding to noise originating in the radiation detecting section, and the second sub-step of correcting the detection signal on the basis of a second correction value corresponding to noise originating in the readouting section, the second sub-step being executed before the first sub-step.

Abstract: The invention relates to a method for operating a radiation examination apparatus, especially an X-ray apparatus, that includes a radiation source and a detector device. The invention proposes the use of a control signal for “during pulse” radiation control, being a combination of a dose or a dose rate signal, measured by a dose rate measuring device, and an adaptive control value that is obtained, using an adaptive control algorithm, from the mean image working points within a selected region of interest of every individual preceding image within an image sequence. A detector device and a radiation examination apparatus are also claimed.

Abstract: Method and system for compensating for the thickness of an organ in a radiology instrument, in which an image of the radiological thicknesses of the organ through which the X-ray beam has passed is calculated on the basis of a digitized image, the thickness image is filtered using a low-pass filter in order to obtain a low-frequency image, the low-frequency image is subtracted from the radiological thickness image in order to obtain a contrast image, the low-frequency image is processed using a pre-recorded table taking into account a contract &khgr; selected by a user in order to obtain an image with reduced dynamic range, and the image with reduced dynamic range is added to the contrast image in order to obtain a compensated thickness image, the pixels having a level below or above a predetermined threshold being returned at least to the value of the threshold, while preserving the differences and real ratios between the anatomical structures.

Abstract: Generation of a drum filming layer is prevented by obtaining a developing agent meeting the relationship y<0.057x+0.1748, where x represents the total addition amount of the additive, which is not smaller than 0.2, and y represents the free component content obtained from the difference in the fluorescence X-ray analytical value between the front surface and the back surface of a pellet of the developing agent, by quantitatively analyzing the free component content of the additive to the developing agent and by using a binder resin satisfying the conditions of 2,000≦number average molecular weight≦5,000, 8,000≦weight average molecular weight≦70,000, and 1.6≦Mw/Mn≦35.

Abstract: A method and system for an automatic exposure control (AEC) arrangement for a matrix-addressed imaging panel having an array of sensors including use of localized regions of the imaging panel exhibiting capacitive coupling. In one embodiment, the matrix-addressed imaging panel includes one or more AEC electrode receptive field regions that provide a signal representative of exposure specific, respective AEC electrode receptive field regions. Additionally, in another embodiment, the imaging array includes data line signal monitoring regions in which capacitive coupling between electrodes in radiation sensors adjacent to the data line are read and processed to provide and AEC signal. In another embodiment, the imaging array includes both AEC electrode filed receptive regions and data line signal monitoring regions that are coupled to an AEC controller for control of the radiation source for the imaging array.

Abstract: When X-ray irradiation is performed with many X doses and the fall of temporary sensibility or the rise of the temporary offset arises, it is the X-ray diagnostic equipment which computes the correction by sensitiveness multiplier based on the sensibility characteristic or offset characteristic of each pixel, and rectifies data. In this X-ray diagnostic equipment, the correction by sensitiveness multiplier for data correction is determined based on the signal value detected last time at least. In integrating this correction by sensitiveness value from each pixel to the output signal, the influence by the fall of temporary sensibility or the rise of the temporary offset is removed.

Abstract: An X-ray apparatus in which a mean value of a weighted histogram obtained by multiplying a histogram of numbers of data corresponding to image intensities in a reference image which is an X-ray image picked up in an X-ray fluoroscopy mode and a weighting function whose variable depends on the image intensities is arithmetically determined for controlling an output power of an X-ray tube so that the mean value of the integrated histogram approaches a predetermined value.

Abstract: In a method and apparatus for measuring the imaging dose in the framework of the registration of a radiation image of a subject, particularly of an x-ray image, a radiation source is employed for generating radiation, a solid-state radiation detector is employed for image pickup and a sensor is employed for calculating the imaging dose, and a radiation detector on a semiconductor base that lies behind the solid-state radiation detector with reference to the direction of the radiation incident onto the solid-state radiation detector is employed, for measuring radiation penetrating through the solid-state radiation detector. The radiation sensor emits an output signal that represents the measured radiation, and the imaging dose at a location in front of the solid-state radiation detector is determined based on the output signal.

Abstract: An X-ray examination apparatus includes an X-ray source with a brightness control signal input, an X-ray image device for providing an X-ray image of an object to be imaged, X-ray absorption means between the X-ray source and the X-ray image device, a brightness control system coupled to the X-ray image device and the brightness control signal input in order to derive a brightness control signal from the X-ray image, and a detection means which is coupled between the X-ray image device and the brightness control signal input in order to exclude a degree of detected absorption from said brightness control signal caused by the absorption means present in the X-ray image. Direct radiation and absorption means (such as filters) in the detected absorption range in a histogram of pixels of the X-ray image are automatically excluded from the brightness control which is thus improved.

Abstract: A method for optimizing the radiogram image of a subject is provided. The method provides for showing the location of automatic exposure control sensors on the radiograms, along with alignment and targeting projections to optimize the radiation exposure of the subject. By displaying the location of the automatic exposure control sensors on the radiograms along with the image of the subject, the observers can determine whether the radiogram image was taken with appropriate subject alignment. This method also serves as an educational aid in training radiography technicians.

Abstract: An X-ray image sensor comprising an array of sensor elements and a sensor characterization storage device is provided. The sensor characterization storage device stores sensor characterization information identifying defects in the array of sensor elements. The X-ray image sensor may have an intergrated interpolator, and the interpolator processes image data from the array of sensor elements by using the sensor characterization information to correct for the defects in the array of sensor elements. An X-ray imaging system comprising the X-ray image sensor and a computer also is provided. The X-ray image sensor provides to the computer a signal corresponding to image data from the array of sensor elements. The X-ray image sensor provides to the computer the sensor characterization information, and the computer processes the image data using the sensor characterization information to correct for the defects in the array of sensor elements.

Abstract: An x-ray examination apparatus comprises an x-ray source for generating an x-ray image and an image analysis system derives brightness variations from the x-ray image and derives a dose control signal dependent on said brightness variations in order to control the x-ray source. The image analysis system derives a distribution of said brightness variations and derives the dose control signal from the distribution of brightness variations. Preferably, the image analysis system is arranged to derive the brightness variations from the processed image and a histogram analysis is employed to derive the dose control signal.