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: There is provided an X-ray CT apparatus that can control an irradiation X-ray dose in accordance with a displacement of an internal organ due to breathing of an examinee or the like with satisfying both of enhancement of image quality and lessening of exposed dose. In preparation processing before scan is started, an X-ray CT apparatus 1 generates a three-dimensional cross-section model from scanogram projection data of an examinee. An operator is made to input a site of interest, an assumed displacement amount of the site and a desired image quality index value. A scan planning unit 405d calculates an X-ray attenuation index from the three-dimensional cross-section model, and corrects the calculated X-ray attenuation index on the basis of the input site of interest, assumed displacement amount and image quality index value. The scan planning unit 405d further determines a tube current modulating pattern (irradiation X-ray dose modulating pattern) on the basis of the corrected X-ray attenuation index.

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: There are provided an X-ray CT scan simulator and an X-ray CT apparatus in which a lesion postulated by an operator can be displayed on a simulation image and a high-precision simulation containing a postulation of occurrence of a new lesion can be performed. They comprise an image storing device for storing a reference image, a target noise value setting device for setting a target noise value of a desired image, a simulated lesion setting device for setting a condition for a simulated lesion postulated by the operator, a simulation image generating device for generating a simulation image containing a simulated lesion by using the reference image on the basis of the set target noise value and the condition for the simulated lesion, and an image display device for displaying the simulation image containing the simulated lesion.

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: An X-ray CT apparatus is provided with an X-ray tube current modulation pattern calculation means that calculates an X-ray tube current modulation pattern based on a 3-dimensional model of an object calculated based on a scanogram image of the object, start-up shape acquisition means that acquires a start-up shape of CT values of a predetermined region of the object or CT value time differences after injecting contrast agent into the object, time contrast curve prediction means that predicts a time contrast curve indicative of a time sequential change of contrast in a diagnostic portion of the object at each slice position at a scan time based on the acquired start-up shape of the CT values or CT value time differences, object 3-dimensional model modification means that modifies a 3-dimensional model of the object based on the predicted time contrast curve, and X-ray tube electric current modulation pattern modification means that modifies the X-ray tube electric current modulation pattern based on the modifi

Abstract: Provided is an X-ray CT apparatus which can perform CT scan of multi-energy scanning at a high speed and can obtain an image having an excellent substance distinguishing ability. The X-ray CT apparatus includes: means to continuously perform a first CT scanning using a first X-ray energy and a second CT scanning using a second X-ray energy without interrupting CT scan; means to transit the X-ray energy emitted from the X-ray during a transition period TR including an end of the first CT scanning and a beginning of the second CT scanning from the first X-ray energy to the second X-ray energy; and means to compensate the scan data in the transition period by the opposing data in the residual scan period so as to reconstruct an image.

Abstract: An image diagnosis supporting system comprising a means for reading in image data representative of the image of a subject acquired by a medical imaging apparatus, a means for detecting an abnormal shadow candidate satisfying at least one of a plurality of criteria for abnormal shadow criteria from the image thus read in, and a means for displaying the image thus read in and a marker indicative of the abnormal shadow candidate thus detected in a superimposed state. The image diagnosis supporting system is further provided with a means for setting criteria supporting judgment of the abnormal shadow candidate detected by the abnormal shadow candidate detecting means as judgment supporting criteria, and a control means for displaying the judgment supporting criteria thus set, the abnormal shadow candidate and the marker simultaneously on the display means. Accordingly, it is possible to support the user in accurately judging the type of an abnormal shadow candidate.

Abstract: An X-ray CT apparatus inputs information with respect to a target tissue of the object to be discriminated in the tomographic image and inputs an index with respect to correctness of the discrimination, and determines scanning conditions for discriminating the target tissue based on the index.

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 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 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 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).