Abstract: A reconstruction image is generated with a small number of updates, with the use of an iterative approximation method. A specified tomographic image of a subject is received, and a process is performed two or more times, where an update process is performed according to the iterative approximation method, using the tomographic image as an initial image and an update image is obtained. Then, an update vector corresponding to a difference between thus generated update images of the update process performed twice is multiplied by predetermined coefficients, so as to generate an estimated update vector. Using this vector, an update image is generated. Then, this update image is used as a new initial image, and a process is repeated where the update process is performed according to the iterative approximation method and an update image is obtained, thereby generating a tomographic image of the subject.

Abstract: A separation unit is a configuration that is arranged vertically, and thus bubbles generating from the electrode will not negatively influence the contact location between the transfer membrane and separation unit. An anode (32) is arranged at a position separated by a certain distance in the conveying direction (X) of the transfer membrane (1) from the dispensing part (50a) of an electrophoresis gel chip (50). An insulating electrode cover (35) for setting free bubbles generating from the anode (32) is arranged at an upper part of the anode (32).

Abstract: In order to provide a data processing device and the like, capable of performing highly accurate reference correction even in a case where an object protrudes in reference channels in most of the measurement views, an image processing device (data processing device) of an X-ray CT apparatus calculates a unit air calibration reference value which is a value per unit tube current of an air calibration reference value which is reference data measured during air calibration, calculates a reference value (estimated reference value) corresponding to an X-ray condition in the main scanning on the basis of an output tube current value in the main scanning and a unit air calibration reference value, and corrects normalized reference data obtained by normalizing a measured reference value in the main scanning with the estimated reference value, to be included in an allowable error range, so as to remove the influence of protrusion.

Abstract: In order to provide an X-ray CT apparatus which can reconstruct a tomographic image with less unevenness in image quality at a high speed on the basis of projection data which is obtained by irradiating an object with X-rays, the X-ray CT apparatus of the invention includes an inverse projection phase width setting unit that sets an inverse projection phase width which is an angular width of projection data used for reconstruction, for each tomographic image, and a view weight calculation unit that calculates a view weight which is a weight coefficient multiplied by projection data within the inverse projection phase width and is a function of a view angle, for each position of a pixel of a tomographic image.

Abstract: In order to reduce a metal artifact using a short process, without causing image quality deterioration, when a subject containing metal is imaged in an X-ray CT apparatus, the invention is such that a high frequency component is extracted utilizing the fact that a high frequency component is a structure in error projection data, which are a difference between primary corrected projection data wherein at least one portion of an artifact component caused by metal has been removed and photographed projection data acquired by imaging. The high frequency component, extracted while carrying out weighting in order to suppress the metal artifact, is restored to the primary corrected projection data, after which an image is reconstructed. Also, metal projection data used when compiling the primary corrected projection data are calculated from a value that is a CT value corresponding to soft tissue subtracted from a CT value of a metal region.

Abstract: In a case where helical scanning, etc., is performed in an X-ray CT apparatus, upsampled projection data that more approximates to an observed value is obtained. There is provided an X-ray CT apparatus that improves spatial resolution of an overall effective field of view without reducing rotation speed, in an FFS method of acquiring projection data through moving of an X-ray focus position to a plurality of positions. The X-ray CT apparatus: converts projection data acquired through helical scanning into projection data of normal scanning performed by one rotation; generates a virtual-counter-data space in which virtual counter data are acquired on substantially coincident X-ray transmission path in the converted projection data; performs upsampling in a view direction; and similarly upsamples FFS projection data in the view direction for focus-shifted projection data obtained by performing the helical scanning while causing the X-ray focus position to shift (virtual counter data space generation).

Abstract: In order to determine noise intensity more accurately by a projection data division method using data after fan-parallel conversion, a plurality of projection data obtained by irradiating a scan object with radiations are received and subjected to prescribed data conversion; data after the conversion is divided into two or more sets; a reconstructed image is generated for each set of data; and the generated reconstructed image for each of the sets is subtracted to generate a difference image. An index indicating pixel value variation for at least one prescribed region on the difference image is calculated, the value of the index is corrected by a previously calculated correction value, and the corrected index value is regarded as noise intensity of the region.

Abstract: An X-ray CT apparatus includes an extraction unit that acquires air data measured using the X-ray CT apparatus and the measurement data obtained by scanning the object, that extracts sensitivity variation data which is a sensitivity variation component of a detection element from the air data, and that extracts blank data from which the sensitivity variation component is removed, and a projection data generation unit that removes the sensitivity variation component and noise which are included in the measurement data, based on the sensitivity variation data, and that uses the blank data so as to perform a correction process of the measurement data from which the sensitivity variation component and the noise are removed.

Abstract: In order to reduce a metal artifact using a short process, without causing image quality deterioration, when a subject containing metal is imaged in an X-ray CT apparatus, the invention is such that a high frequency component is extracted utilizing the fact that a high frequency component is a structure in error projection data, which are a difference between primary corrected projection data wherein at least one portion of an artifact component caused by metal has been removed and photographed projection data acquired by imaging. The high frequency component, extracted while carrying out weighting in order to suppress the metal artifact, is restored to the primary corrected projection data, after which an image is reconstructed. Also, metal projection data used when compiling the primary corrected projection data are calculated from a value that is a CT value corresponding to soft tissue subtracted from a CT value of a metal region.

Abstract: A reconstruction image is generated with a small number of updates, with the use of an iterative approximation method. A specified tomographic image of a subject is received, and a process is performed two or more times, where an update process is performed according to the iterative approximation method, using the tomographic image as an initial image and an update image is obtained. Then, an update vector corresponding to a difference between thus generated update images of the update process performed twice is multiplied by predetermined coefficients, so as to generate an estimated update vector. Using this vector, an update image is generated. Then, this update image is used as a new initial image, and a process is repeated where the update process is performed according to the iterative approximation method and an update image is obtained, thereby generating a tomographic image of the subject.

Abstract: In order to provide a technique capable of restoring measured data from projection data with high accuracy and removing system noise included in the measured data, a signal processing device obtains measured data x including signal values of 0 or less by processing an output signal from a data acquisition system, and performs a conversion process on the measured data x by using a predefined function including a logarithmic function so as to generate projection data (logarithmically converted data z), in which the predefined function is a function of which an inverse function is present for values of a predetermined negative number s or more, and the measured data x including signal values of 0 or less within a predetermined range is restored from the projection data by applying the inverse function to the projection data.

Abstract: In order to provide an X-ray CT apparatus which can reconstruct a tomographic image with less unevenness in image quality at a high speed on the basis of projection data which is obtained by irradiating an object with X-rays, the X-ray CT apparatus of the invention includes an inverse projection phase width setting unit that sets an inverse projection phase width which is an angular width of projection data used for reconstruction, for each tomographic image, and a view weight calculation unit that calculates a view weight which is a weight coefficient multiplied by projection data within the inverse projection phase width and is a function of a view angle, for each position of a pixel of a tomographic image.

Abstract: In order to provide a technique for reducing system noise from an output signal value (measurement data), an X-ray CT apparatus includes an X-ray generation unit that irradiates X-rays to an object, an X-ray detector that detects the X-rays transmitted through the object, a correction processing unit that corrects an output signal from the X-ray detector, and a reconstruction calculating unit that reconstructs an image on the basis of an output from the correction processing unit, in which the X-ray detector includes arranged detection elements, and in which the correction processing unit maintains an average value of output signal values of a plurality of predetermined detection elements centering on a focused detection element among the detection elements, and also reduces a variance of the output signal values of the plurality of predetermined detection elements centering on the focused detection element.

Abstract: In order to provide a data processing device and the like, capable of performing highly accurate reference correction even in a case where an object protrudes in reference channels in most of the measurement views, an image processing device (data processing device) of an X-ray CT apparatus calculates a unit air calibration reference value which is a value per unit tube current of an air calibration reference value which is reference data measured during air calibration, calculates a reference value (estimated reference value) corresponding to an X-ray condition in the main scanning on the basis of an output tube current value in the main scanning and a unit air calibration reference value, and corrects normalized reference data obtained by normalizing a measured reference value in the main scanning with the estimated reference value, to be included in an allowable error range, so as to remove the influence of protrusion.

Abstract: A CT image reconstructing method, a CT image reconstructing device and a CT system are provided for reducing motion artifacts in CT images in case of motion of an object. The CT image reconstructing method reconstructs CT images from projection data obtained by X-ray scanning, including a moving object position detecting step for detecting a position of a moving object in a CT image; a partial angle selecting step for selecting a view point and an angle range according to said position of the moving object and selecting data of partial angles in said projection data according to said view point and said angle range; a partial angle constraint step for generating partial angles constraint conditions according to the data of said partial angles; and an iterative reconstruction step for generating CT images by iterative reconstruction, thereby improving temporal resolution of CT images of moving objects and reducing motion artifacts.

Abstract: In a case where helical scanning, etc., is performed in an X-ray CT apparatus, upsampled projection data that more approximates to an observed value is obtained. There is provided an X-ray CT apparatus that improves spatial resolution of an overall effective field of view without reducing rotation speed, in an FFS method of acquiring projection data through moving of an X-ray focus position to a plurality of positions. The X-ray CT apparatus: converts projection data acquired through helical scanning into projection data of normal scanning performed by one rotation; generates a virtual-counter-data space in which virtual counter data are acquired on substantially coincident X-ray transmission path in the converted projection data; performs upsampling in a view direction; and similarly upsamples FFS projection data in the view direction for focus-shifted projection data obtained by performing the helical scanning while causing the X-ray focus position to shift (virtual counter data space generation).

Abstract: In order to provide a data processing method and the like capable of suppressing high-frequency errors such as moiré using data uniformly by presuming that adjacent pixels and beams overlap and performing calculation in a back projection process or a forward projection process for reconstructing images, the image processing device 122 sets a pixel size wider than a pixel interval, performs the back projection process or the forward projection process for calculating an interpolation value to be assigned to the pixels or the beams using a size-dependent weight (pixel window) according to an overlap amount of the adjacent pixels, sets a beam size wider than a beam interval, and then performs the back projection process or the forward projection process for calculating an interpolation value to be assigned to the pixels or the beams using a size-dependent weight (beam window) according to an overlap amount of the adjacent beams.

Abstract: An X-ray CT apparatus includes an extraction unit that acquires air data measured using the X-ray CT apparatus and the measurement data obtained by scanning the object, that extracts sensitivity variation data which is a sensitivity variation component of a detection element from the air data, and that extracts blank data from which the sensitivity variation component is removed, and a projection data generation unit that removes the sensitivity variation component and noise which are included in the measurement data, based on the sensitivity variation data, and that uses the blank data so as to perform a correction process of the measurement data from which the sensitivity variation component and the noise are removed.

Abstract: In order to provide an X-ray CT apparatus and a contrast enhanced scanning method that can obtain an image having a favorable contrast effect without re-injecting contrast medium even when a scanning position overtakes a position of the contrast medium during scanning using the contrast medium, the X-ray CT apparatus determines whether or not a current scanning position overtakes the contrast medium during main scanning, resets a scanning condition when overtaking the contrast medium, executes re-scanning under the reset scanning condition, and determines overtaking of the contrast medium based on differential data between measurement data acquired by non-contrast enhanced scanning to be performed before the main scanning and measurement data to be acquired by the main scanning. Hence, no image needs to be reconstructed during scanning to check whether or not there is a contrast effect, and the overtaking determination is performed at a high speed, which can swiftly shift to re-scanning.

Abstract: In order to provide a technique capable of restoring measured data from projection data with high accuracy and removing system noise included in the measured data, a signal processing device obtains measured data x including signal values of 0 or less by processing an output signal from a data acquisition system, and performs a conversion process on the measured data x by using a predefined function including a logarithmic function so as to generate projection data (logarithmically converted data z), in which the predefined function is a function of which an inverse function is present for values of a predetermined negative number s or more, and the measured data x including signal values of 0 or less within a predetermined range is restored from the projection data by applying the inverse function to the projection data.