Abstract: The invention relates to an automatic exposure control of an imaging implemented by electromagnetic radiation, in particular to prioritizing and selecting several automatic exposure signals in connection with mammography imaging, to be used in such a way that areas having darkened too little would not be left into the image to be formed, at least not in the area of the breast tissue. A selection process of the signals makes up an essential part of the invention, in which signals are selected for the basis of control of imaging parameters according to signal values, and possibly also according to the physical location of the signal sources, on the grounds of the selection criteria according to the invention.

Abstract: The invention relates to an arrangement and a method in digital mammography imaging, wherein X-radiation is produced by an X-radiation source (2), the radiation produced is filtered and the radiation containing image information is detected by means of an imaging sensor (5). According to a preferred embodiment of the invention, the X-radiation is produced using an acceleration voltage of over 30 kV and a tungsten anode, the radiation emitted from the anode (11) is filtered using a silver filter (13) substantially having a thickness of about 75 ?m, and the radiation containing image information is detected by means of a sensor based on amorphous selenium technology.

Abstract: A digital imaging apparatus and method which includes a radiation source and a sensor arrangement for detecting radiation. The sensor arrangement contains one or more sensors formed of one or more preferably elongated sensor modules, which sensor module contains one or more pixel columns which receive image data. The digital imaging apparatus includes means for positioning the object to be Imaged which is situated within the area between the radiation source and the sensor arrangement, and means for limiting the beam from the radiation source essentially according to the active sensor surface of the said sensor arrangement. Also included is means to move the beam across the object being positioned to be imaged and means to move the at least one sensor belonging to the sensor arrangement in synch with the scanning movement of the beam in order to keep the active sensor surface essentially at right angles to the beam on the plane formed by the scanning movement.

Abstract: The invention relates to an automatic exposure control of an imaging implemented by electromagnetic radiation, in particular to priorizing and selecting several automatic exposure signals in connection with mammography imaging, to be used in such a way that areas having darkened too little would not be left into the image to be formed, at least not in the area of the breast tissue. A selection process of the signals makes up an essential part of the invention, in which signals are selected for the basis of control of imaging parameters according to signal values, and possibly also according to the physical location of the signal sources, on the grounds of the selection criteria according to the invention.

Abstract: The present invention relates to automatic exposure control implemented in imaging by electromagnetic radiation, in particular to automatic exposure control in film-based mammography, which is based on a completely new approach as compared with the solutions currently in use, which utilize adjustment curves and/or tables constructed on the basis of empiric tests. The new approach includes modeling into the AEC system the radiation spectra obtainable from the radiation source as a function of its operating parameters and attenuation of the spectrum as the radiation traverses components of the imaging apparatus. By measuring the thickness of the object to be imaged and knowing the initial spectrum and its calculable behavior, a correspondence between the AEC signal and the desired darkening of the image can be achieved which is based on true density of the object being imaged.

Abstract: The invention relates to digital scanning imaging by electromagnetic radiation. To reduce the difference between the resolutions in, the scanning direction and the direction perpendicular thereto, pixels (P1, P2, P3, P4, P5, P6) in the scanning direction are connected to counters (C1, C2, C3) through switching means (Sm1, Sm2, Sm3) which allow pulses to be directed to the counter of a neighboring pixel, in addition to its own pixel, for counting, whereby the reading area can be divided into a plurality of “partial pixels” and by suitably changing the switch positions, it is possible to follow the imaging scan as reading areas formed by the “partial pixels”.

Abstract: The imaging apparatus used in mammography generally having a cassette tunnel (17) or a similar space for the placement of an image data receiving device (14?) in the imaging area of the apparatus. In such a space or in its immediate vicinity, device (19) for moving the cassette in the space can be provided, thus making the imaging process in many ways faster and easier to carry out. Such device for moving the cassette can also be utilized in various ways to achieve a more versatile and more accurate use of the imaging apparatus.

Abstract: The invention generally relates to imaging of an object by electromagnetic radiation, especially to digital mammography performed by scanning technique. According to the invention, movement of a digital sensor of a mammography apparatus, synchronized with scanning movement of the beam, is performed by keeping the active surface of the sensor essentially at right angles to the beam, on a plane formed by scanning movement of the beam, while at the same time distance from the sensor to the radiation source is continuously adjusted so that its path in the direction of scanning movement of the beam becomes essentially linear.

Abstract: The present invention relates to automatic exposure control implemented in imaging by electromagnetic radiation, in particular to automatic exposure control in film-based mammography, which is based on a completely new approach as compared with the solutions currently in use, which utilize adjustment curves and/or tables constructed on the basis of empiric tests. The new approach includes modeling into the AEC system the radiation spectra obtainable from the radiation source as a function of its operating parameters and attenuation of the spectrum as the radiation traverses components of the imaging apparatus. By measuring the thickness of the object to be imaged and knowing the initial spectrum and its calculable behavior, a correspondence between the AEC signal and the desired darkening of the image can be achieved which is based on true density of the object being imaged.

Abstract: A sensor arrangement and method for digital X-ray imaging. The sensor arrangement in digital X-ray imaging includes at least one sensor element which absorbs X-radiation and contains a medium, which has a relatively thin semi-conductor material structure, that converts X-ray quanta into electron-hole pairs. The surface of the element opposite to the surface receiving the X-radiation is provided with electrodes for dividing the sensor element into at least two pixel columns. Each pixel electrode is provided with detection electronics and a counter for counting the voltage or current pulses generated by the electron-hole pairs. The counters for adjacent pixel columns are connected to each other so that the counters for the pixels can be loaded from the counter for the corresponding pixel on the same row in the preceding pixel column.

Abstract: The invention relates to digital scanning imaging by electromagnetic radiation. To reduce the difference between the resolutions in, the scanning direction and the direction perpendicular thereto, pixels (P1, P2, P3, P4, P5, P6) in the scanning direction are connected to counters (C1, C2, C3) through switching means (Sm1, Sm2, Sm3) which allow pulses to be directed to the counter of a neighbouring pixel, in addition to its own pixel, for counting, whereby the reading area can be divided into a plurality of “partial pixels” and by suitably changing the switch positions, it is possible to follow the imaging scan as reading areas formed by the “partial pixels”.

Abstract: The invention relates to solutions where biased (photoelectric) (semiconductor) material (e.g. Ge, Si, Se, GaAs, HgI, CdTe, CdZnTe, PbI) converts X-ray quanta directly into electron-hole pairs, each of which, by using an intensive electric field connected across said material, can be collected, avoiding lateral diffusion, into the area of its respective pixel. The X-ray quanta are detected and the amount of the ones exceeding the possibly adjustable threshold level is counted. According to the invention the reading electronics (20) may be implemented by providing for each of the pixels (31, 31′, . . . ) its own junction surface (32) which is connected to the said semiconductor material in a manner by which the reading out of them, as well as for enabling the TDI imaging, the counters (23′, . . . ) for each of the pixels (31′, . . . ) can be loaded parallel from the counters (23, 23′, . . . ) for pixels on the same row in the preceding pixel column.

Abstract: The invention relates to a method and apparatus for constructing a sensor system (100) sensitive to electromagnetic radiation for use in a digital imaging camera head. The sensor system (100) is capable of delivering an electrical signal containing the image information formed by electromagnetic radiation incident on the sensor system (100). The sensor system (100) is comprised of a number (N pcs.) of mutually essentially identical modular sensor units (10.sub.1 . . . 10.sub.N) and of an equal number (N pcs.) of mutually essentially identical modular control electronics units (20.sub.1 . . . 20.sub.N) suited for the control and signal processing of said sensor units (10.sub.1 . . . 10.sub.N). The sensor system (100) has a modular design permitting the dimensions of the imaging area covered by the sensor system (100) to be expanded or reduced as required for the needs of an imaging application by adding or reducing, respectively, the number of the modular sensor units (10,20).

Abstract: The present invention concerns methods and apparatuses for imaging an object by detecting radiation reflected from and/or transmitted through the object (O;P;M) using an imaging sensor system. To perform an optimized selection between the imaging resolution and the sensitivity of the imaging sensor, the sensor system is configured by means of a control scheme based on combining, or binning, the radiation-responsive imaging elements of the imaging sensor along the rows and/or columns of the sensor matrix into clusters of a plurality of imaging elements. The sensor pixel charges, which represent the image information obtained from the individual imaging elements of said clusters, are straightforwardly binned into the clusters in their charge form. According to a second method of the invention, the TDI-mode imaging technique is applied and a mutual, relative motion is arranged between object to be imaged and the imaging sensor.

Abstract: The invention concerns a method and an apparatus for marking a radiographic film in a dark room with patient data and/or similar information. The marks to be produced are made latent onto the film (F) in a form turning visible during the development of the film (F). The film (F) to be marked is transferred linearly in the marking apparatus, while the film (F) is simultaneously subjected to exposing marking radiation. The marking characters to be formed are sequentially composed from vertically adjacently placed elements (C.sub.1 . . . C.sub.N) using the above-mentioned linear motion of the film (F) as the shift in the direction of the marking character row. In conjunction with the entry of patient data, the identification information for the film cassette to be marked is entered from a keyboard such as a cassette number which is marked on the cassette in a form visible in the dark.

Abstract: Method in x-ray diagnostics for regulating the exposure of a film or equivalent to an optimal level. The radiation that has passed through an object is measured by detectors and, based on this measurement, the time of exposure regulated. The measurement signals are passed from the detector or from different detectors to an amplifier associated with each detector. The amplifications of the amplifiers are initially calibrated by exposing a reference object to a predetermined dosage, passing the amplified signals from the detectors one at a time to an integrator for an initial switching period, comparing each amplified and integrated signal with a reference value, and independently adjusting the switching period of each amplified signal to produce amplification values so that each detector and amplifier gives an integrated signal equal to the reference value.

Abstract: The invention concerns a method and apparatus for narrow-beam tomography in which x-ray radiation is aimed to pass through the object to be radiographed onto a movable (v.sub.1) x-ray film (F). The object (P) is kept stationary in a certain position, while the x-ray source and the film cassette (14) are rotated about a vertical virtual axis of rotation (A-A). In the first operating mode for the panoramic radiography of the dental arch the patient (P) is supported by positioning means so that the sharply imaging plane (P-P) is located between the virtual axis of rotation (A-A) of the x-ray beam (X) and the film plane. In the second operating mode for the radiography of transversal projections of the dental arch (L) the patient (P) is supported in such a stationary position that the virtual axis of rotation (A-A) of the x-ray beam (X) is located in the area between the sharply imaging tissue layer (P-P) and the film plane (F).

Abstract: Method and device for controlling the operations of a mammographic X-ray apparatus. In the apparatus the breast (4) to be photographed is pressed between a press plate (2) and a film cassette (5) or an equivalent depicting member. In the method the compression force (F) applied by the holder means to the breast (4) to be photographed, or a quantity that represents this force (F) indirectly, is measured. On the basis of the measurement, the velocity (V) of the compression movement of the press mechanism is regulated. The apparatus comprises a C-arm (1), at one of whose ends the X-ray tube (6) is placed and at the other end the film cassette (5). The C-arm (1) is rotatable around a shaft (8) by means of a motor (9). The device comprises a detector (3) or a series of detectors which measures the compression force and by means of which the operation of the press motor (7) for the breast holders is arranged to be controlled.

Abstract: Methods and apparatuses in mammographic photography, wherein the breast (M) to be photographed is pressed and spread between holders (6,7) attached to the photographing apparatus. A beam (R) of X-radiation is directed from one side of the holders (6,7) through the breast (M) placed between the holders at depicting means (21) placed at the opposite side of the holders in relation to the source (2) of X-radiation, said depicting means being placed inside a film cassette or equivalent placed in connection with the frame of the apparatus. In order to carry out the photography of a breast (M.sub.1 ; M.sub.2 ;M.sub.3) in different projections (f;g;h), the frame part (25) of the apparatus, in which the source (2) of radiation, the depicting means (21), as well as the breast holders (6,7) are fitted, is turned around such an axis (b--b) as substantially coincides with the central axis (a--a) of the breast (M) to be photographed, which is being pressed by the breast holders (6,7).

Abstract: Method and apparatus for marking a film with information, e.g. patient data and other possible information in X-ray photography, such as panoramic tomography. The X-ray beam creating the X-ray photograph, and the X-ray film move in a certain manner in relation to one another. A certain area of the film is reserved for markings which are latently made thereon, to become visible when the X-ray film is developed. Markings are made simultaneously with the film exposure to the X-ray beam for the X-ray photography. The markings are sequentially made by using relative movement of the radiation with which the marking is made upon the film and the film itself, such relative movement being synchronized with the relative movement of the X-ray beam to which the film is exposed for the actual X-ray photography, and the film itself, the relative movement preferably representing a parallel deflection or displacement along a marking row.