Abstract: A tomograph which determines projection data phase range capable of back projection for each reconfigured voxel with an arbitrary value larger than ? so that the absolute values of cone angles at the ends of this phase range is minimized, calculates an approximate straight line for a curve indicating the position of a radiation source with respect to the channel direction position of parallel beam projection data obtained by a parallel beam of a parallel shape viewed from the go-around axis direction generated from the radiation source, and based on the determined projection data range capable of back projection, three-dimension back projects the parallel beam projection data subjected to filter processing created through a filter correction to the back projection region corresponding to the region in concern along the approximate irradiation trace of the radiation beam calculated using the calculated approximate straight line, thereby suppressing generation of the distortion attributed to data discontinuity,

Abstract: A weighting function is created according to an arbitrary bio-movement correction range and a projection data angle for back-projection (width in the view direction used for reconstruction), set by a user, by considering the degree of the bio-movement and redundancy. By using this weighting function, an image reconstruction is performed. The bio-movement correction range is set as a correction angle width index ? expressing the width guaranteed as a slope portion of the weighting function. The projection data angle for back-projection (data width) is determined by considering the data redundancy, SN, time width (time resolution) contributing to the image. By determining the weight according to these two parameters, it is possible to apply reconstruction of projection data of all the scan ranges in the reconstruction of the tomogram and prevent lowering of the data contribution ratio as well as reduce the motion artifact, thereby obtaining a high-quality image.

Abstract: An X-ray CT apparatus comprising: a scanner unit for rotating one or more X-ray sources for applying X-ray beams having different energy spectra to an object, and detectors disposed opposed to the X-ray sources for detecting transmitted X-ray data on the object, around the object while applying X-rays, reconstructing means for reconstructing a tomogram of the object by acquiring transmitted X-ray data on the object including the two or more different energy spectra by using the scanner, and display means for displaying the reconstructed tomogram; the X-ray CT apparatus further comprising input means for inputting information on an identification tissue of the object to be identified and a separate tissue to be separated from the identification tissue from the tomogram and scanning condition determining means for determining the scanning condition for identifying the identification tissue from the tomogram. With this, an optimum scanning condition of a multi-energy X-ray CT apparatus can be determined.

Abstract: An X-ray CT apparatus acquires a scanogram of an object to be examined, generates an ellipse model having an X-ray attenuation coefficient equivalent to that of water and approximated to a tomographic image of the obtained imaged portion from the feature quantity of the projection value profile, determines whether or not the generated elliptic model is adequate as a model of the imaged portion from another feature quantity with respect to the projection value profile, generates a corrected elliptic model according to yet another feature quantity with respect to the projection value profile if the elliptic model is determined to be inadequate, and controls the modulation of the tube current in an X-ray source so that a predetermined target SD value is maintained in any scanning position when a tomographic image is reconstructed according to X-rays transmitted through the object by using the elliptic model or the corrected elliptic model.

Abstract: An X-ray CT apparatus includes a projection data analysis part that reconstructs a tomographic image at an imaging portion of the object used for analysis from the projection data and produces a control profile by reprojecting the reconstructed tomographic image, and a tube current control part that controls value of current to be fed to the X-ray tube based on the produced control profile.

Abstract: The photon counting type detector 122 includes a drift electrode 122a, an MSGC 122b provided at a prescribed interval and a drift region 122c formed by sealing gas between the drift electrode 122a and the MSGC 122b. The projection data outputted from the photon counting type detector 122 is discriminated by the discrimination circuit 162 for each of X-ray energies and a CT image is reconstructed based on the projection data after discrimination, thereby providing an energy discrimination type X-ray CT apparatus capable of improving image quality at lower cost.

Abstract: An X-ray CT apparatus that can obtain a tomogram having high spatial resolution without increasing the effect of system noise and dosage is provided. The X-ray CT apparatus has an X-ray source for emitting X-ray, an X-ray detector having plural X-ray detecting elements that detect X-ray transmitted through an examinee as attenuation data and are arranged in a channel direction, a data combining unit for combining attenuation data of plural X-ray detecting elements in the channel direction to obtain composite data, a data decomposing unit for decomposing composite data to obtain respective decomposition data of the plural X-ray detecting elements, and an image re-constructing unit for re-constructing an image of the examinee by using the decomposition data.

Abstract: [Problems] To provide an X-ray CT apparatus capable of easily comparing image quality supposed to be obtained when not using a X-ray dose optimization function and image quality supposed to be obtained when using the X-ray dose optimization function at the stage of scan planning. [Means for Solving Problems] A 3-dimensional model of an object to be examined (17) is generated from scanogram projection data (S170). An image noise dispersion value corresponding to an imaging region of the object is predicted from the 3-dimensional model. The predicted image noise dispersion value is compared to a desired value of the image index value inputted by a user so as to calculate a modulation pattern of the irradiation X-ray amount (S200). By predicting the image quality supposed to be obtained when using and not using the X-ray dose optimization function, each of the predicted results is displayed so as to be compared on a display device (5) (S230).

Abstract: In an X-ray CT apparatus comprised with an X-ray generating means, an X-ray detector disposed opposing to the X-ray generating means, a rotating means for rotating the X-ray generating means and the X-ray detector on a circular orbit of a same rotation center, a control means for controlling so as to irradiate X-rays from the X-ray generating means to an object laid along the rotation center and to detect by the X-ray detector X-ray dose penetrated through the object while rotating the X-ray generating means and the X-ray detector through the rotating means and a reconstruction computing means for performing reconstruction computation by making use of the data of the penetrated X-ray dose obtained under the control of the control means and acquiring a tomographic image, the X-ray CT apparatus further being comprised with an input means being inputted of information with respect to an target tissue of the object to be discriminated in the tomographic image and of an index with respect to correctness of the dis

Abstract: A radiographing apparatus according to an aspect of the present invention is characterized in that an image processing device comprises an acquisition device which acquires projection data of a first energy spectrum and projection data of a second energy spectrum, and a synthetic image generating device which synthesizes a first image on the basis of the projection data of the first energy spectrum, and a second image on the basis of the projection data of the second energy spectrum according to a predetermined synthetic condition, and generating a synthetic image, and a display device displays the generated synthetic image.

Abstract: An X-ray CT apparatus is provided, having a function for deciding an X-ray imaging condition prior to scanning, the X-ray imaging condition allowing an acquisition of contrast to noise ratio appropriate for identifying a diagnostic object. Prior to the real scan, a three-dimensional model of an object is estimated from scanogram projection data of the object, a contrast to noise ratio enabling identification of the diagnostic object is calculated, based on the diagnostic object size set by an operator via an operating device when planning the scan, the three-dimensional model, and a standard imaging condition that is stored in a storage device. Then, an optimum irradiated X-ray condition (tube current and tube voltage) is calculated for achieving the contrast to noise ratio enabling identification. The X-ray condition being calculated is displayed in the form of information such as image SD value and exposure dose, under the calculated X-ray condition and under other condition.

Abstract: A radiotomograph comprises radiation detecting means which applies radiation from a radiation source to a subject from many direction and detects radiation transmitted through the subject from the directions, a bed on which the subject lies and which can move the subject in the direction of the body axis of the subject, reconstruction parameter setting means which sets reconstruction parameters including the amount of movement of the bed in the direction of the body axis and used to reconstruct, an image of the subject, reconstruction view area calculating means which calculates the reconstruction view area for at least one data segment necessary for reconstruction calculation determined for each position in a space reconstructed according to the set reconstruction parameters, reference segment position setting means which sets a reference segment position in the calculated reconstruction view area according to a phase signal generated by dynamic state analysis of the subject, effective segment calculating me

Abstract: [Problems] To provide an X-ray CT apparatus capable of easily comparing image quality supposed to be obtained when not using a X-ray dose optimization function and image quality supposed to be obtained when using the X-ray dose optimization function at the stage of scan planning. [Means for Solving Problems] A 3-dimensional model of an object to be examined (17) is generated from scanogram projection data (S170). An image noise dispersion value corresponding to an imaging region of the object is predicted from the 3-dimensional model. The predicted image noise dispersion value is compared to a desired value of the image index value inputted by a user so as to calculate a modulation pattern of the irradiation X-ray amount (S200). By predicting the image quality supposed to be obtained when using and not using the X-ray dose optimization function, each of the predicted results is displayed so as to be compared on a display device (5) (S230).

Abstract: A weighting function is created according to an arbitrary bio-movement correction range and a projection data angle for back-projection (width in the view direction used for reconstruction), set by a user, by considering the degree of the bio-movement and redundancy. By using this weighting function, an image reconstruction is performed. The bio-movement correction range is set as a correction angle width index ? expressing the width guaranteed as a slope portion of the weighting function. The projection data angle for back-projection (data width) is determined by considering the data redundancy, SN, time width (time resolution) contributing to the image. By determining the weight according to these two parameters, it is possible to apply reconstruction of projection data of all the scan ranges in the reconstruction of the tomogram and prevent lowering of the data contribution ratio as well as reduce the motion artifact, thereby obtaining a high-quality image.

Abstract: An X-ray CT apparatus of the present invention includes: an X-ray source which irradiates X-rays; an X-ray detector which is arranged oppositely to the X-ray source and detects the irradiated X-rays; a scanner having a rotary disk which rotatably supports the X-ray source and X-ray detector and a power source of the rotary disk; an image processing device which makes the scanner rotate in a state where an object is inserted in between the X-ray source and the X-ray detector to irradiate the object with X-rays from directions at a plurality of angles, and makes the X-ray detector detect X-rays transmitted through the object in directions at a plurality of angles as projection data, to reconstruct a tomographic image of the object by the use of the projection data in the directions at the plurality of angles; a display device which displays the reconstructed tomographic image; a setting device which sets X-ray irradiation condition candidate by at least one combination of a tube current and a tube voltage for p

Abstract: In an X-ray CT apparatus comprising an X-ray source irradiating X-rays to an object, an X-ray detector that is disposed oppositely to the X-ray source in a manner placing the object therebetween and is to detect transmitting X-rays through the object as projection data, a rotating means that rotates the X-ray source and the X-ray detector, a control means that collects the projection data from plural angular directions obtained through rotation of the X-ray tube and the X-ray detector by the rotating means, performs reconstruction computation of these collected projection data to produce tomographic images of the object as well as controls the X-ray source and the rotating means and a display means that displays the produced tomographic images, the X-ray CT apparatus further comprising a projection data analysis means that reconstructs a tomographic image at an imaging portion of the object used for analysis from the projection data and produces a control profile by reprojecting the reconstructed tomographic

Abstract: An image reconstruction area of a subject is divided into a plurality of image data segments, among projection data obtained by projection, projection data segments necessary for back projection processing are cut out for every image data segments and back projection processing is performed for every image data segments by making use of the cut out projection data segments. Further, detector addresses of the projection data to be used for the back projection processing are obtained from a plurality of limited number of detector addresses within the concerned image data segment region. As a result, a device is realized which permits to produce a high quality tomographic image with high speed by using a small amount of a high speed memory.

Abstract: A radiotomography apparatus according to the present invention includes a radiation detection device that irradiates radiation from a radiation source in multiple directions around an object to be examined and detects radiation transmitted through the object from the multiple directions; a table on which the object lies and which can move the object in a body axis direction of the object; reconstruction parameter setting device that sets reconstruction parameters that include an amount of movement of the table in the body axis direction, and that are used to reconstruct an image of the object; a reconstruction view area calculating device that calculates a reconstruction view area for at least one data segment that is necessary for a reconstruction calculation that is determined for each spatial position that is reconstructed based on the set reconstruction parameters; a reference segment position setting device that sets a reference segment position in the calculated reconstruction view area according to a p

Abstract: An image reconstruction area of a subject is divided into a plurality of image data segments, among projection data obtained by projection, projection data segments necessary for back projection processing are cut out for every image data segments and back projection processing is performed for every image data segments by making use of the cut out projection data segments. Further, detector addresses of the projection data to be used for the back projection processing are obtained from a plurality of limited number of detector addresses within the concerned image data segment region. As a result, a device is realized which permits to produce a high quality tomographic image with high speed by using a small amount of a high speed memory.

Abstract: An image processing method comprises: an inputting step of inputting image data which is obtained by imaging a subject for a predetermined period of time with a medical imaging apparatus and is arranged in time series; an extracting along the time axis step of extracting pixels which satisfy a predetermined condition along the time axis from all the pixels arranged in time series for each pixel coordinate position with respect to each pixel in the image data; and a constructing step of constructing a two-dimensional or three-dimensional image based on the pixels extracted along the time axis in the extracting along the time axis step.