Abstract: In a method of detecting a prospective abnormal shadow in an image at a predetermined detecting level, the detecting level is changed according to prior information on the object.

Abstract: The subject invention pertains to a novel method and apparatus for improving the efficacy of a medical treatment or diagnostic procedure by coordinating such treatment or procedure with a patient's breathing cycle. In a specific embodiment, the subject invention pertains to a novel method of coordinating a chest x-ray with a patient's ventilatory cycle. In a specific example, this invention concerns a novel device for interfacing a ventilator and an x-ray machine to ensure that an x-ray chest image can be taken at peak insufflation of the patient. The subject invention also relates to other medical procedures including, but not limited to, cardiac output measurement, chest imaging, inhalation therapy, oxygen delivery, blood pressure measurement, and pulse oximeter optoplethysmograms. By coordinating certain medical treatments and diagnostic procedures with a patient's breathing cycle, the subject invention improves the quality of medical care received by the patient.

Abstract: The present invention, in one form is an imaging system for generating images of an entire object. In one embodiment, a physiological cycle unit is used to determine the cycle of the moving object. By altering the rotational speed of an x-ray source as a function of the object cycle, segments of projection data are collected for each selected phase of the object during each rotation. After completing a plurality of rotations, the segments of projection data are combined and a cross-sectional image of the selected phase of the object is generated. As a result, minimizing motion artifacts.

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: A method and apparatus for use with a computed tomography (CT) system that collects CT radiograph data for every view of the CT gantry so that a data set corresponding to all views of the gantry is available for use in reconstructing an image of a patient's heart and coronary vasculature. For each view of the gantry, the CT radiograph data associated with the view is collected at different instants in time with respect to the period of the cardiac cycle in each revolution of the gantry. Prior to data acquisition, the patient's heart rate is measured and the period of the gantry is set such that data is acquired at a different time with respect to the period of the cardiac cycle for every view of the gantry and for each revolution of the gantry.

Abstract: An improved acquisition scheme for a medical imaging and treatment system 100. According to one aspect of the invention, adaptive radiation detection, for determining when therapeutic or diagnostic radiation is being applied, is provided. The imaging device 124 acquires several test images during a preacquisition delay. The maximum intensity level from these test images is defined as the upper limit of a camera 122's response in the darkness. The standard deviation of the intensity distribution is also computed. The image intensity level of the subsequent test images are compared to a radiation detection threshold which is determined to be the upper limit of the camera's dark signal, plus twice the standard deviation of pixel intensity distribution of the dark test images. If the intensities of a statistically significant number of pixels exceeds the threshold, the radiation is considered to be on.

Abstract: A method for improving the quality of a fluoroscopic image where the image out of an image sequence of images which satisfies a predetermined minimum motion criterion is stored and this stored image is continuously displayed. The images may be acquired using a pulsed cardiac fluoroscope.

Abstract: In a method and X-ray device for the pickup of X-ray images in an examination of a vessel or organ that moves substantially rhythmically, particularly for the determination of deposits in a vessel, such as a coronary vessel, the X-ray pickup system of an X-ray device is slowly moved along a circular orbit at an angular velocity of less than 6° per second, during which a number of digital X-ray images are picked up, with the image pickup being triggered by the vessel motion or organ motion acquired during the system movement or by an organ motion that causes the vessel motion, and a 3D image is reconstructed on the basis of the individual images, after the image pickup has ensued.

Abstract: Radiological imaging device comprising an emitter of an X-ray beam and a receiver of the X-ray beam after it has crossed an organ, the organ being capable of being placed between the receiver and a compression element, capable of being removably fixed on the device. A calculation unit includes a means for optimizing the image quality over a particular area defined by the compression element.

Abstract: The subject invention pertains to a novel method and apparatus for improving the efficacy of a medical treatment or diagnostic procedure by coordinating such treatment or procedure with a patient's breathing cycle. In a specific embodiment, the subject invention pertains to a novel method of coordinating a chest x-ray with a patient's ventilatory cycle. In a specific example, this invention concerns a novel device for interfacing a ventilator and an x-ray machine to ensure that an x-ray chest image can be taken at peak insufflation of the patient. The subject invention also relates to other medical procedures including, but not limited to, cardiac output measurement, chest imaging, inhalation therapy, oxygen delivery, blood pressure measurement, and pulse oximeter optoplethysmograms. By coordinating certain medical treatments and diagnostic procedures with a patient's breathing cycle, the subject invention improves the quality of medical care received by the patient.

Abstract: The present invention, in one form, is an imaging system which synchronizes the emission of x-rays and the collection of data to a heart cycle to provide improved image quality. In one embodiment, the imaging system utilizes a synchronization unit to determine a selected heart period and to control generation of x-ray beams during the selected period. As the x-ray beams are emitted toward a detector, data is collected for a view angle. As the heart continues to cycle, data for a series of view angles is collected so that an image of the heart during the selected period is generated.

Abstract: This invention relates to a radiographic apparatus which comprises a radiographic image photographing unit for photographing a radiographic image of an object irradiated with radiation by a radiation generating device, a distance measuring system for measuring the distances or distance from the radiation generating device to the radiographic image photographing unit and/or the object, and distance information indicating means for indicating distance information obtained by the distance measuring system.

Abstract: An X-ray computerized tomography apparatus which includes: an X-ray generating source for irradiating an object with X-rays; a unit for detecting X-rays transmitted through the object; a scan unit for controlling direction of irradiation with X-rays so that a periphery of the object is scanned in a predetermined direction with the X-rays from the X-ray generating source; and a control unit for controlling a scan speed of the scan unit on the basis of an external signal synchronized with movement of a part or whole of the object.

Abstract: An X-ray examination apparatus for generating an X-ray image of an object, wherein X-ray image generator includes a brightness control input, image processor coupled to the X-ray image generator in order to output a brightness control signal to the control input. The X-ray image generator is provided with an X-ray data output, the image processor is provided with an X-ray data input coupled to the X-ray data output, and the image processor is arranged as calculating system for calculating absorption properties of the object and for generating the brightness control signal in dependence on the absorption properties. Intelligent measuring field selection is now possible on the basis of calculating absorption properties of identifiable objects or parts of objects reproduced in the visible image. Image quality is improved because of brightness control based on more intelligently selected measuring fields.

Abstract: The invention relates to an X-ray device which operates with only a single image detection device whose format corresponds to the maximum exposure format. In order to facilitate the adjustment of the exposure field for an exposure, a respective set of exposure parameters is stored in a memory for each of the various organs to be imaged; this set includes inter alia an adjustment value for the size of the exposure field for an exposure of the relevant organ. This adjustment value is fetched and the diaphragm unit is automatically controlled in such a manner that the fetched adjustment value is (pre)adjusted.

Abstract: In one aspect, the present invention is a method for producing CT images of a patient's heart suitable for calcification scoring, in which the heart has a cardiac cycle. The method includes steps of acquiring data representative of a first scout-scanned CT image of physical locations of the patient's body including at least a portion of the patient's heart at phases &phgr;1(L) of the cardiac cycle, acquiring data representative of a second scout-scanned CT image of the physical locations of the patient's body including at least a portion of the patient's heart at phases &phgr;2(L) of the cardiac cycle different from &phgr;1(L) at physical positions L of interest, and determining a difference image from the acquired data representative of the first scout-scanned CT image and the acquired data representative of the second scout-scanned CT image data. It is not necessary that &phgr;1(L) and &phgr;2(L) be constant as a function of position L.

Abstract: An imaging system which, in one embodiment, includes a timing algorithm which identifies the proper projection data to be used and a modified halfscan image reconstruction algorithm which provides improved image quality along with the benefits of an enhanced temporal response, is described. In an exemplary embodiment, the timing algorithm includes the steps of determining a diastolic period of a patient's heart and corresponding projection data during the diastolic period. The modified halfscan algorithm includes the steps of identifying redundant data and unequally weighting the data. The resulting images are used for coronary calcification detection.

Abstract: Pixel data in a region of a flat panel detector is obtained and displayed. For example, pixel data in a region irradiated with X-ray is obtained and displayed. The region to be irradiated with-the X-ray is estimated according to a degree of opening of an X-ray beam limiting device and a distance between the X-ray beam limiting device and the flat panel detector. Further, it can be determined from pixel data value of the flat panel detector also. A region of a patient can be also determined from the pixel data. Thus, an image corresponding to the entire flat panel detector, an image corresponding to an X-ray irradiation region and an image corresponding to a patient region can be displayed. A resolution for obtaining the pixel data is changed corresponding to the size of a region in the flat panel detector whose pixel data should be obtained and a processing resolution of an image processing means at post step.

Abstract: The present invention, in one form, is an imaging system which includes a verification system for verifying the proper connection of an interconnection cable. In accordance with one embodiment of the verification system, a verification circuit verifies operation of the interconnection cable by altering the patterns supplied from an EKG subsystem. More specifically, the conduction of interconnection cable is verified prior to, during and after scanning the patient by transmitting patterns received from the EKG subsystem through the verification circuit back to the EKG subsystem. If the patterns match the expected patterns, a verification signal is generated indicating proper cable connection.

Abstract: A method for providing automatic brightness control in a closed loop x-ray imaging system which utilizes an automatic brightness system (ABS) sampling window. The location, size and shape of the ABS sampling window is adjusted in accordance with statistical information including spatial gray scale distribution data derived from the data related to the x-ray system and image being processed, thereby enabling the automatic brightness control to make brightness and power adjustments in accordance with statistical data from the modified ABS sampling window.

Abstract: An x-ray imaging system provides automatic adjustment of x-ray tube voltage and current based on an identification and removal of background pixels in the image and a calculation of the functional relationship between voltage and current and dose for the particular imaged object as deduced from two exposures at different voltages. Real-time image distortion removal and image rotation are accomplished by computer processing using a generalized image transformation polynomial. Scatter in the image is reduced by calculating a scatter map based on a blurring of the received image and normalizing the scatter map to point scatter measurements made with an x-ray occluder eliminating direct exposure of certain areas of the image. Improved signal to noise ratio in a moving x-ray image is provided by averaging stationary portions of the image over a longer time than the moving portions of the image.

Abstract: A radiographic/fluoroscopic imaging system provides rapid transition from fluoroscopic to radiographic imaging mode by maintaining the X-ray tube high voltage, increasing the filament current, allowing X-ray tube current to increase toward the desired radiographic current, and terminating exposure when the desired X-ray dose has been achieved. Rapid transition from radiographic to fluoroscopic imaging mode is provided by reducing x-ray tube high voltage to produce an equivalent fluoroscopic-level x-ray output at high initial current, dropping filament current, and enabling ABS control of the high-voltage. As x-ray tube current drops, ABS correspondingly increase high voltage to maintain the desired output. The imaging system obtains movement-related information by analyzing a video signal (such as from fluoroscopic image or an image from an optical camera trained on the patient), or from operator movement requests.

Abstract: The invention relates to a process for avoiding radiation injury in diagnostic radiology by measuring the change in concentration of endogenous substances in bodily fluids. In addition, the invention comprises a device for implementing this process.

Abstract: In a method and an apparatus for the radiological examination of individual cardiac phases of a patient, an X-ray beam is rotated around and penetrates the heart of a patient from various angular positions and the attenuated X-ray beam strikes a radiation detector. The cardiac rhythm of the patient is determined in order to set the rotation time of the X-ray beam around the patient and to produce various control signals synchronized to the cardiac rhythm of the patient, so that radiological exposures of various cardiac phases are possible for the duration of a measurement interval. The setting of the rotation time of the X-ray beam so that the rotation time is larger or smaller, by the measurement interval, than the cycle time of the cardiac rhythm of the patient, so that after a few rotations there is a phase displacement of 360.degree. between the rotating X-ray beam and the cardiac rhythm of the patient.

Abstract: The present invention, in one embodiment, is an interference detection assembly for detecting patient and patient table interference with a gantry of a computed tomography system. The assembly, in one form, includes a frusto-conical capacitive plate secured to a leading frusto-conical surface of the gantry bore. The capacitive plate is coupled to a control unit which detects changes in the capacitance of the capacitive plate. When the plate is discharged below a threshold charge, the control unit generates a signal which may be used to automatically interrupt a scan.

Abstract: A radiation therapy apparatus and method for applying radiation to a patient in synchronism with one of a plurality of states of a cardiac cycle of the patient and one of a plurality of states of a respiratory cycle of the patient. An electrocardiograph is operatively connected to the patient and a respiratory monitor is operatively connected to the patient. A controller is provided for receiving an output from said electrocardiograph indicative of which of said plurality of cardiac cycle states the cardiac cycle is presently in and for receiving an output from said respiratory monitor indicative of which of said plurality of respiratory cycle states said respiratory cycle is presently in. A radiation applicator applies radiation to the patient in response to a trigger signal from the controller, said trigger signal being generated by said controller in response to said output from said electrocardiograph and said output from said respiratory monitor.

Abstract: A computer is provided for calculating input data for an X-ray machine which is about to be used for making an X-ray of a body part. The computer has a multiplicity of input devices each dedicated to inputting particular information that should enter into the input information for an X-ray machine including a series of input devices each dedicated to one pathological disease that the body to be X-rayed may have, input devices dedicated to particular body parts, and an input device dedicated to body part thickness. A program causes the computer to compute the input data for the X-ray machine based on the information fed to the computer via the input devices.

Abstract: An X-ray examination apparatus includes an exposure control circuit (20) which supplies a control signal for adjustment of the X-ray source (1). The exposure control circuit (20) determines the control signal from an area of the X-ray image in which no overexposure occurs. To this end, the exposure control circuit includes a selection unit (23) for determining a measuring part from an electronic image signal, formed from the X-ray image by means of an X-ray detector (5, 8, 7), by comparing the signal level of the electronic image signal with an upper limit value which is dependent on the setting of the X-ray apparatus, for example of the high voltage and the anode current of the X-ray source. The upper limit value preferably amounts to the difference between the overexposure level and a safety margin. The safety margin serves to render the exposure control circuit insensitive to small fluctuations of the intensity and energy of the X-ray beam (3) generated by the X-ray source (1).

Abstract: An ultrasonic ranging system for providing a distance to a subject signal for use in positioning a movable imaging element support structure with respect to a subject of examination includes a collar assembly disposed around a portion of the imaging element structure disposed towards an imaging region; a plurality of ultrasonic transducers disposed in a sensing pattern around the collar assembly; and an ultrasonic ranging processing unit coupled to the transducers to control processing of ultrasonic ranging signals from the transducers. The transducers are typically disposed in one or more rows on the surface around the circumference of the collar assembly such that the lobes of ultrasonic signals generated provide a desired ranging field.

Abstract: A capacitive proximity detection system for positioning a movable radiation imaging element support structure with respect to a subject includes a plurality of sensor plates disposed in a collar assembly around a portion of an imaging component disposed towards a subject; a multiplexer coupled to the plurality of capacitive plate elements and adapted to selectively electrically couple the sensor plate elements in one of a plurality of sensing range modalities; and a capacitive sensing processor coupled to the sensor plate elements via the multiplexer so as to detect proximity of object to the sensor plate as a function of the capacitance between the sensor plates and the subject. The imaging system typically further includes a shield system coupled to the multiplexer and disposed so as to focus the capacitive sensing of the sensor plate elements towards the subject.

Abstract: A method and apparatus are disclosed for predicting prior to injection an organ specific contrast enhancement in a patient for a preselected contrast injection protocol for pre-determining a computed tomography scan. The invention is preferably implemented in a computer program which creates a mathematical model of human cardiovascular physiology in a hypothetical patient with a specific body habitus subjected to the pre-selected contrast injection protocol. The predicted contrast enhancement is then displayed for operator approval and may be then used to control a CT scanner to perform the scan with the pre-selected injection protocol. The mathematical model includes models of organs and vessels using differential equations to describe mass transport of contrast agent through the cardiovascular system.

Abstract: A method and system for identifying end systole and end diastole frames within an angiography sequence. A plurality of images produced during an angiography sequence are digitized, producing digital image data in which gray scale values for each of the pixels in the images are represented. The digital image data are input to a computer (48) to determine the frames in which the coronary arteries are most visible. The coronary arteries are made visible in the images by injecting a radio-opaque contrast substance into the arteries. The frames that occur a end diastole are preferred for diagnostic analysis because the arteries are distended, spread apart from each other, and moving very slowly. To identify such frames for further analysis, the total length of edges within a centered window covering approximately one-fourth of each image is determined. The edges represent spatial transitions between relatively light and dark areas in the image that occur across the borders of the coronary arteries.

Abstract: A fluoroscopic imager for observing a living creature with reduced x-ray dosage uses a video monitor for displaying frames of image samples received during respective ones of frame scan intervals that regularly and successively occur at a display frame rate sufficiently high that brightness flicker is acceptably low to a human observer; an x-ray source that can be gated on for intervals not as long as a display frame; and a fluoroscopic camera, including a raster-scanning video camera and x-ray-to-light conversion apparatus with persistence not appreciably longer than a display frame and frame-filling apparatus. Especially during purely diagnostic procedures, the frame-filling apparatus generates a continuous succession of frames of image samples at the display frame rate by interpolating between successively grabbed frames of image samples.

Abstract: An x-ray diagnostics installation for peripheral angiography examinations includes a control unit having an arithmetic unit that, on the basis of subject-related data supplied thereto, effects a pre-setting of the electrical parameters of the installation required for every exposure, plus the step length and the number of steps of the relative adjustment of the exposure unit and the patient support relative to one another, as well as the required diaphragm setting. By virtue of the pre-setting, stress on the patient is reduced, and since the overall time per examination is also reduced, patient throughput can be increased.

Abstract: In mammographic examinations, the breast being examined is compressed with increasing force between a pressure plate and a support platform. A method and apparatus are disclosed for generating an optimal compression pressure which is adapted to the size of the breast being examined, so as to insure reliably high image quality. In the method and apparatus, the compression pressure of the pressure plate against the breast is controlled so that the increase in compression force is stopped when a change in breast thickness reaches a predetermined value. The appartus includes a measuring device for establishing the distance between the pressure plate and the support platform, thereby establishing the thickness of the breast as the compression force increases, and a control device which stops the increase in the force of compression when the change in this distance reaches a predetermined value.

Abstract: A medical imaging system has a source of X-rays and a detector which produces an electrical signal in response to X-rays. A signal generated by the detector, during an acquisition interval, is used to construct an image of a medical patient, which may contain artifacts due to motion of patient. A signal is produced indicative of the motion, which has a quiescent period of minimum movement. A first portion of the signal is selected such that if image acquisition commenced at the end of the first portion, the acquisition interval would occur during a quiescent period. This first portion is initially used as a reference signal portion. Then subsequent portions of the signal are compared to the reference signal portion to produce a descriptor of the degree of similarity. An image acquisition is commenced when the descriptor indicates a given degree of similarity that is above a defined threshold.

Abstract: In an X-ray CT (computerized tomographic) apparatus, a simple programmable anatomical selecting operation is realized. The X-ray CT apparatus comprises: selecting means for selecting at least one of imaging sorts and imaging portions with respect to a biological body under medical examination; means for programming a medical examination scheme based upon the one of imaging sorts and imaging portions of the biological body; first storage means for storing therein the programmed examination scheme; and, means for reading out the programmed examination scheme from the first storage means so as to sequentially execute functions of the programmed examination scheme.

Abstract: An x-ray source (20) rotates about a fixed cylinder (16) within which a subject of non-uniform cross-section is received. Radiation from the x-ray source passes through the subject and impinges on an arc of radiation detectors (28). Because the subject is of non-uniform cross-section, the average x-ray energy fluence impinging on the detectors across the arc varies with the relative angular position of the x-ray source and the subject. In one embodiment, a motor (18) which rotates the x-ray tube relative to the subject is controlled by a digital motor control (50). The digital motor control varies the rotational speed to a preselected angular velocity indicated by a look-up table (52) at each of a multiplicity of angular positions around the subject.

Abstract: A method for fluoroscopically observing a living creature with reduced x-ray dosage is usable with a video monitor for displaying frames of image samples received during respective ones of frame scan intervals that regularly and successively occur at a display frame rate sufficiently high that brightness flicker is acceptably low to a human observer; an x-ray source that can be gated on for intervals not as long as a display frame; a fluoroscopic camera, including a raster-scanning video camera and a x-ray-to-light conversion apparatus with persistence not appreciably longer than a display frame; and frame filling apparatus for grabbing frames of image samples and interpolating between successively grabbed frames of image samples, when necessary, to generate frames of image samples at said display frame rate.

Abstract: The disclosure concerns radiology instruments that include an X-ray source, a receiver of the film or film-screen type, a detection cell and means to compute the yield at the cell. The method consists of performing measurements of the yield at instants t.sub.1, t.sub.2, . . . t.sub.3 during the exposure, so as to determine the lumination or luminous exposure (the quantity of the light received multiplied by the exposure time) on the film and then computing the lumination remaining to be acquired to obtain the chosen optical density on the film.

Abstract: An automatic x-ray exposure unit has first and second radiation detectors disposed sequentially and in registry in the direction of radiation propagation following the examination space. Each radiation detector is formed by a matrix of detector elements, also in registry. The detector elements are connected to a computer which calculates the quotient of the signals of each pair of detector elements in the first and second radiation detectors which are in registry. Those pairs of detector elements having a signal quotient which is above a predetermined threshold are automatically taken into consideration for selecting the measuring field for an x-ray exposure.

Abstract: An object replicator that replicates the physical form of an object in a polymer or the like by employing a Computed Tomography scanner or a Magnetic Resonance Imaging system, to digitize the physical features of the object to be copied. This data is used to form an electronic three-dimensional representation of the object. The electronic representation is then sectioned and provided to a three-dimensional printer to replicate a copy of those features by sequentially forming and joining laminae corresponding to the sections, to build up a physical replication of the object in a step-wise fashion whereby the three dimensional object is auto-matically formed from a composite of laminae.

Abstract: An X-ray diagnostic apparatus, comprises an X-ray source (1), an imaging surface (6) on which the intensity distribution of the X-rays to be applied to a test object (4) is imaged, an optical imaging device for imaging an overall image (10) of the imaging surface (6) onto the entrance surface of a first image sensor (11), a device (12) for the visual display of the overall image (10), and an imaging enlargement device for the enlarged visual display of a selectable detail of the overall image. Strongly enlarged and still high-resolution detail images are generated in that the selectable detail (20) of the overall image is directed onto a second image sensor 16) which discriminates a substantially higher number of pixels relative to the unit of surface area of the overall image.

Abstract: A protection cover includes a pressure responsive means mounted within the cover along its inner wall surface and which operates responsive to external forces to be exerted upon contact with a neighboring object. The protection cover is provided at a portion where physical contact may occur between any of movable or rotating component devices of an X-ray diagnostic apparatus, such as, an X-ray exposure unit or an image intensifier, and a neighboring object which is in the path of the component devices, such as, a subject or a catheter table. The protection cover may, for example, be provided at a moving end of a component X-ray diagnostic apparatus, such as, the forward end of the image intensifier, or may be mounted, instead of being mounted on a movable component device, on a neighboring object at its side facing to the movable part of the component devices, such as, a stand section of the catheter table, which lies in the path of a moving part of the X-ray radiographing component devices.

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: An X-ray inspection apparatus and method allow inspection of the contents of containers moving rapidly past an inspection station. The system includes an X-ray source pulsed by control logic, an image amplifier for converting an X-ray image of the container contents to a visible image and a solid-state camera for converting the visible image into video signals which are processed by a computer-controlled image processor. Clear images are produced of the contents of rapidly moving containers by pulsing the X-ray source. Control logic and a reject mechanism eject containers having foreign contaminants. Image illuminance stability is enhanced by feedback signals from the vision computer which operate a motorized camera lens.

Abstract: A periodically moving object, e.g., the heart, is X-rayed in response to periodic pulses generated at instances in the period at which the object is anticipated to be in a given position. Stochastic movements shift the position of the object at those instances such that image artifacts may result. A prediction methodology is utilized to predict when the object has moved stochastically and therefore will be out of position at the forthcoming pulse. That forthcoming pulse is then suppressed to preclude imaging the object out of position. Kalman filtering is utilized in the prediction methodology.

Abstract: A main body comprising a gantry having an X-ray tube and a detector incorporated therein and a bed is disposed within a test room. A main console for general use and a simplified console are disposed within an operation room. The main console permits selection of all the sequences conducted by an X-ray CT apparatus and setting of all the parameters. The simplified console has some of the functions available by the main console, and it inhibits selection of a certain sequence and setting of certain parameters, automatically selects such a sequence, and automatically sets such parameters. The main console and simplified console are coupled to a CPU through a selector and console I/F. A disk memory device is also coupled to the CPU. The selector normally connects the main console to the console I/F and connects the simplified console to the console I/F when instructed by a command from the simplified console.

Abstract: A method of reducing image artifacts in tomographic, projection imaging systems due to periodic motion of the object being imaged includes the acquisition of a signal indicative of the periodic motion. This signal is used to identify a quiescent period in the periodic motion so that the acquisition of projection data may be coordinated to be centered within the quiescent period. The sequence of the angles at which projection data is acquired is controlled so that the primary axis of periodic motion is perpendicular to the axis of projection at the center of the quiescent period. Multiple periodic signals may be coordinated by awaiting their best alignment over a fixed number of cycles of one of the periodic motions.

Abstract: A structure and method for providing optimum recording of X-ray images without need for experimenting to learn optimum X-ray tube voltage, current, anode focal spot size and exposure time. The method and structure of this invention sample the radiation passed through an object to be radiographed during a short portion of the total exposure time and adjust voltage, current and focal spot size so that the radiation delivered by the X-ray tube during the remainder of the exposure time will produce optimum contrast between structures within the object being radiographed, also optimum sharpness of the image and optimum darkening of a film, xerographic picture, fluoroscopic image, or other recording medium. The method and structure of this invention account for variations in absorption coefficient between one object to be radiographed and the next. This invention is particularly useful for medical applications, and in the medical field, particularly important in mammography.