Abstract: Methods, apparatus and systems for an exact filtered back projection process for circle-plus trajectories, which consist of two components: C and L. The first component C, is analogous to a circle in the traditional circle-plus trajectories, is any closed (not necessarily planar) continuous curve. The second component L is almost any continuous curve. The only condition is that L starts below C and ends above C. The process does not depend on the global properties of L. When the source is located on L, one needs to know only how C projects onto the corresponding detector and the properties of L in the immediate neighborhood of the source position. The present invention is especially convenient for the traditional circle-plus trajectories, which are implemented using a gantry and moving table by obtaining a universal FBP algorithm, which is independent of table movement during the scan as long as the condition on L is satisfied.

Abstract: An optical communication system includes a rotatable base having a plurality of optical sources and optical receivers mounted thereon, and a stationary base having a plurality of optical sources and optical receivers mounted thereon. The system is configured to send and receive optical signals bi-directionally between the rotatable base and the stationary base while the rotatable base is rotating.

Abstract: In an X-ray CT apparatus, an X-ray source and an X-ray detector mounted in a guide arm are freely movable in such a direction as to approach to and separate from a sample. With respect to this movement, the center of gravity of the whole containing respective constituent elements mounted in the guide arm is kept on the rotational axis by a weight balance adjusting mechanism. The weight balance adjusting mechanism contains a movable weight which is freely movable to the guide arm. The movement of the movable weight is controlled so that a difference between the rotational moment around the rotational axis is offset and substantially equal to zero. The moving passage of the movable weight is set on a straight line which is parallel to the moving direction of the X-ray source and the X-ray detector and does not pass through the rotational axis.

Abstract: An X-ray CT apparatus includes a fixed gantry having a plurality of stator coils arranged in a circle and mounted on the fixed gantry. A ring-shaped rotation frame of the CT apparatus includes a plurality of rotor magnets facing the plurality of stator coils. The CT apparatus further has an X-ray tube and an X-ray detector situated on the rotation frame to face each other and a supporting unit configured to provide non-contact support of the rotation frame on the fixed gantry. A magnetic pole detection unit of the apparatus is configured to detect a magnetic pole position of the rotor magnet at a start-up time of the plurality of stator coils and a brake mechanism of the apparatus is configured to apply a brake load to the rotation frame when detecting the magnetic pole position and to remove the brake load after detecting the magnetic pole position.

Abstract: An method of computed tomography is disclosed herein. The method includes acquiring an axial dataset and acquiring a helical dataset as part of an acquisition protocol. A computed tomography system is also disclosed.

Abstract: An X-ray CT device including a stationary part; a rotary part rotatable relative to the stationary part; an X-ray tube provided at the rotary part for radiating X-ray beams on an object; an X-ray detector provided at the rotary part opposing the X-ray tube, and that detects the X-ray beams passed through the object; an image processor that generates cross-sectional images of the object based on a detection signal outputted from the X-ray detector; a display that shows the cross-sectional images based on output signals delivered from the image processor; a first transmitting section configured by a rotary step-up transformer having a primary and secondary windings residing at the stationary and the rotary part respectively, and that steps up AC voltage provided by AC power source, and that further executes non-contact power transmission from the stationary part to the rotary part for supplying power to the X-ray tube.

Abstract: A computer tomography apparatus (100) for examination of an object of interest (107) comprising an electromagnetic radiation source (104) adapted to emit electromagnetic radiation to an object of interest (107), a detecting device (108) adapted to detect electromagnetic radiation generated by the electromagnetic radiation source (104) and passed through the object of interest (107), and a motion generation device (101, 119) adapted to move the electromagnetic radiation source (104) and the detecting device (108) with respect to the object of interest (107) along a first trajectory and along a second trajectory which differs from the first trajectory, wherein the second trajectory is selected in such a manner that electromagnetic radiation detected during performing the second trajectory provides data which complete mathematically incomplete data detected during performing the first trajectory to thereby allow a reconstruction of structural information concerning the object of interest (107).

Abstract: A method and apparatus for imaging an object including the steps of projecting radiation from a radiation source through an object and moving the radiation source through multiple imaging positions relative to the object without stopping movement of the radiation source. Movement is accomplished while projecting radiation at more than one of the imagining positions with the source having a source velocity for at least one imaging position that is different from a source velocity for a second imaging position. Radiation transmitted through the object is also detected. Radiation may be projected while moving the radiation source through the multiple imaging positions. In addition, the velocity at which the radiation source is moved through a select imaging position may be related to a resolution desired for data collection at the select imaging position. The velocity of the radiation source may be varied within a select imaging position.

Abstract: A rotary electrical contact device includes a stationary member configured to be coupled to a base, and a rotatable member supported for rotation relative to the stationary member and defining a center opening. A raceway includes a plurality of axially spaced annular contact rings supported by one of the stationary member and the rotatable member. A blade tower includes a plurality of axially spaced blade assemblies and is supported by the other of the rotatable member and the stationary member. Each blade assembly includes a radially extending contact blade in electrical communication with one of the axial spaced contact rings of the raceway.

Abstract: A data processing device, comprising a plurality of emitter antennas arranged on a movable data acquisition device and adapted to emit electromagnetic radiation including data acquired by the movable data acquisition device, a plurality of receiver antennas each adapted to receive the electromagnetic radiation emitted by each of the plurality of emitter antennas, and a data processing unit coupled to the plurality of receiver antennas and adapted to extract the data acquired by the movable data acquisition device from the electromagnetic radiation received by the plurality of receiver antennas.

Abstract: The invention relates to a method and a system for the reconstruction of an object function (f(x)) based on projections acquired during the motion of a radiation source on a helical trajectory (17). The method is particularly suited for an n-PI+ acquisition which by definition completely comprises an n-PI and additionally some overscan data from the (n+2)-PI window. According to the method, two sets (??m, ?>m) of filtered projections are generated from the measuring values and separately back-projected to yield two absorption functions. The first absorption function (flf(x)) is based on contributions of Radon-planes with at most m intersections with the source trajectory (17), while the second absorption function (fhf(x)) is based on Radon-planes with more than m intersections with the source trajectory (17). The two absorption functions are added to yield the final absorption function (f(x)) of an object in the examination zone.

Abstract: A method and apparatus for multi-phase cardiac CT imaging includes an adaptive, selective reconstruction process that, when possible, implements an image or non-phase location driven reconstruction process to reconstruct cardiac CT images. If the hardware parameters support an image location driven reconstruction for the particular imaging session then the image location driven reconstruction is implemented. However, if image location driven reconstruction is not supported, a default phase location driven reconstruction is employed. Image location driven reconstruction improves system throughput and improves image quality as more cardiac phase locations can routinely be generated to better “freeze” the motion of the heart of a patient.

Abstract: An X-ray computed tomographic apparatus includes a rotary frame, a mechanism which rotatably supports the rotary frame, an X-ray tube which is mounted to the rotary frame, an X-ray detector which is mounted to the rotary frame, a plurality of rotor magnets which is arranged in the rotary frame, a plurality of stator coils which is opposed to the rotor magnets, an MR sensor which detects a magnetic-flux variation accompanied by a movement of the rotor magnets, and a position specifying unit which specifies a magnetic-pole position of each rotor magnet with respect to each stator coil on the basis of an output of the MR sensor and a convergence time from a vibration start of the rotary frame caused by a short-time excitation of the stator coil to a vibration stop of the rotary frame.

Abstract: In a device for contact-free transmission of electrical signals between two gantry parts of a computed tomography system that rotate relative to one another, at least one annular, circumferential transmitter element is mounted on one gantry part to transmit the electrical signals, and at least one receiver element to receive the signals emitted by the transmitter element is mounted on the other gantry part. The transmitter element is formed by a single conductor running on a surface, this conductor representing an electrical reference ground (zero potential). At least one dielectric immediately follows on the surface, and multiple conductive conductor structure pairs are executed in two mirror-image parts and are mounted on the at least one dielectric.

Abstract: According to an aspect of the present invention, there is provided an X-ray CT scanner including: a gantry; a revolving body provided inside the gantry; an X-ray tube assembly provided in the revolving body; a heat radiator provided inside the revolving body so as to be connected to the X-ray tube assembly; a heat storage material provided in the heat radiator and capable of accumulating a heat generated by the X-ray tube assembly; and an X-ray detector provided inside the revolving body so as to oppose the X-ray tube assembly.

Abstract: The present invention is directed to realize an X-ray CT apparatus and a scan control method of performing contrast imaging by a helical shuttle scan with a smaller exposure amount. An X-ray CT apparatus for performing contrast imaging by repeating a reciprocating helical scan on a region in a subject repeats the helical shuttle scan (solid-line arrow) including, in shuttle (broken-line arrow) of a helical shuttle scan using an X-ray of a first X-ray dose, a helical scan using an X-ray of a second X-ray dose higher than the first X-ray dose. The start timing of the helical scan using the X-ray of the second X-ray dose is determined on the basis of a change in the CT number of a region of interest of an image captured by a helical scan using the X-ray of the first X-ray dose.

Abstract: Methods and apparatus for producing an image of an object with a multi-slice imaging apparatus having a row of detectors are provided. The method includes generating a first partial image using projection data acquired at a first imaging position in a step-and-shoot imaging mode, generating a second partial image using projection data acquired at a second imaging position, and combining the partial images to form a final image.

Abstract: The invention relates to an angiographic x-ray diagnostic device for rotation angiography with an x-ray emitter which can be moved on a circular path about a patient located on a patient support table, with an image detector unit which can moved on the circular path facing the x-ray emitter, with a digital image system for recording a plurality of projection images by means of rotation angiography, with a device for image processing, by means of which the projection images are reconstructed into a 3D volume image, and with a device for correcting physical effects and/or inadequacies in the recording system such as truncation correction, scatter correction, ring artifact correction, correction of the beam hardening and/or of the low frequency drop for the soft tissue display of projection images and the 3D volume images resulting therefrom.

Abstract: A method of and a system for variable pitch CT scanning for baggage screening and variable pitch image reconstruction are disclosed.

Abstract: Methods and apparatus for an imaging system are provided. The imaging system includes a gantry having a stationary member coupled to a rotating member. The rotating member has an opened area proximate an axis about which the rotating member rotates. An x-ray source provided on the rotating member. An x-ray detector may be disposed on the rotating member and configured to receive x-rays from the x-ray source. A rotary transformer having circumferentially disposed primary and secondary windings may form part of a contactless power transfer system that rotates the rotatable portion of the gantry at very high speeds, the primary winding being disposed on the stationary member and the secondary winding being disposed on the rotating member.

Abstract: A reactive-diffusion method for estimating a diameter of an object of interest includes providing a volume of interest including a plurality of voxels, initializing at least two volumes of the volume of interest, wherein each of the voxels has at least two values corresponding to the at least two volumes of the volume of interest, respectively, performing a diffusion operation and a reaction operation on the voxels to adjust the at least two values, comparing, for each voxel, the at least two values to a threshold to assign each voxel to one of the at least two volumes, wherein the assignment of the voxels is a segmentation result, and estimating a diameter of the object of interest from the segmentation result, wherein the object of interest is represented by at least one of the at least two volumes but less than all the volumes.

Abstract: When a repeatedly periodically moving site of a to-be-examined subject in a gantry is subjected to computed tomography and is reconstructed, the gantry is rotated in synchronization with the movement of the periodically moving site, and a dynamic image showing a transient phenomenon is obtained in which the periodic movement of the moving site has been stopped. As a result, the flow of a contrast agent or the like can be observed in a state of stopping the movement of an internal organ that moves repeatedly periodically.

Abstract: The supporter supports a patient and is disposed movably along the body axis direction of said patient. The imaging part includes an X-ray-generator and an X-ray-detector. The X-ray-generator irradiates X-rays while rotating around the body axis. The X-ray-detector detects the X-rays that have permeated the patient. The collimator changes the irradiation field of the X-rays to be irradiated. The scan controller controls the movement of the supporter and the imaging part. The image-reconstructing part reconstructs image data based on the X-rays that have been detected by the X-ray detector. The movement amount-detector detects the amount of movement of the patient by the supporter. The collimator controller controls so as to change the size of the opening of the collimator based on the amount of movement.

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: Current C-arm examination devices are not capable of performing 360 degrees rotations. The reason for this is that the cabling which connects the external cabinets to the detector, collimator and x-ray tube does not allow for such a rotation. According to an exemplary embodiment of the present invention, an examination apparatus is provided which has a connection device connecting the external cabinets to the C-arm which is adapted for enabling a rotation of the C-arm of more than 360 degrees. Such a connection device may comprise a storing device for winding up the cable.

Abstract: A short scan uses only data from about 180° gantry rotation instead of a full 360° turn. In the provided short scan cardiac CT, a periodical axial focal spot movement is performed during gantry rotation, wherein the acquired data used for image reconstruction results from a 180° rotation of the gantry. After the data acquisition, an approximate reconstruction is performed. In a preferred embodiment the focal spot moves on a short scan saddle trajectory.

Abstract: An imaging section includes a radiation source that emits radiation, a detecting panel for detecting the radiation, and a rotating section for integrally rotating the radiation source and the detecting panel about a rotating axis. The radiation source and the detecting panel face each other with the rotating axis that passes though a predetermined position interposed therebetween. The imaging section sequentially images a subject placed at the predetermined position while rotating the radiation source and the detecting panel about the rotating axis, and image signals are read out for each imaging operation. A control section refers to a necessary readout region set by a setting section and controls a readout switching means such that image signals recorded in detection pixels within the necessary readout region are read out by a normal readout section, and image signals recorded in other detection pixels are read out by a high speed readout section.

Abstract: A CT scanner and method are designed to scan a preselected portion of a patient's lower abdomen. The scanner may include a source and detector array designed to rotate about a rotation axis oriented substantially parallel to or coincident with the hips of the a patient so that a scanning plane does not pass through the patient's pelvic bones Higher-resolution image CT images can be achieved by using a detector array of the type used for digital radiography. The presence of prostatic cancer can be detected by first injecting the patient with a material including a high contrast material for X-ray imaging and a material for binding the high contrast material to a specific biological site if present in the preselected portion of the lower abdomen of the patient; and generating a CT image of the preselected portion of the lower abdomen.

Abstract: A scanning method and apparatus useful for correcting artifacts which may appear in a primary short circular CT scan are provided. A secondary helical scan performed on a stationary subject, or a secondary circular scan, may be used to correct for artifacts. The secondary scan may be performed with a smaller radiation dosage than the primary circular CT scan.

Abstract: An X-ray computer tomography apparatus includes a cone beam X-ray tube X-rays, a two-dimensional array type X-ray detector, a rotating mechanism which supports the X-ray tube, together with the X-ray detector, so as to be rotatable around the object, a reconstruction processing unit which reconstructs a full scan image based on projection data, of the projection data, which corresponds to a view count corresponding to one rotation and also reconstructs a short scan image based on projection data corresponding to a view count smaller than the view count corresponding to one rotation, a CT value shift distribution generating unit which generates a spatial distribution of CT value shifts originating from the smaller view count based on the full scan image and the short scan image, and a correcting unit which corrects the short scan image based on the spatial distribution of the CT value shifts.

Abstract: The present invention provides a method for positively acquiring projection data for reconstructing a CT image at a slice position outside the linear movement range. When performing “projection data acquisition” with “rotating” and “linearly moving” the X-ray tube and the multidetector, a holding time is provided in which only the “rotation” is performed without “linear movement” at the starting point and the end point of the linear movement. By adjusting the holding time, the projection data in the view angle range required for image reconstruction of a CT at the slice position outside the linear movement range can be positively acquired, when the rotating velocity is slower or when the linear movement velocity is faster.

Abstract: Fins are arranged on the rotating side of an X-ray computed tomography apparatus. The fins are rotated to generate airflow as the rotating side is rotated. This airflow serves to discharge wear debris to the outside of the X-ray CT apparatus, thereby preventing the wear debris from scattering toward an X-ray tube and support bearing. In consequence, in the X-ray CT apparatus provided with a slip ring, the wear debris produced in a contact space between the slip ring and a brush can be prevented from being scattered in the apparatus.

Abstract: The present invention aims to obtain a tomographic image similar in image quality to a tomographic image obtained by executing a scan at X-ray tube current value set by an X-ray automatic exposure function even when the X-ray tube current value set by the X-ray automatic exposure function are not within a standard range of the X-ray tube current values settable at the X-ray tube (21). X-ray tube current value supplied to the X-ray tube (21) are set by the X-ray automatic exposure function. Thereafter, when the X-ray tube current value set by the X-ray automatic exposure function is not within in the standard range of the X-ray tube current value settable at the X-ray tube, the X-ray tube current value at a portion not within the standard range are changed so as to be within the standard range, and the set value of helical pitch is changed so as to correspond to the ratio between the pre-changed x-ray tube current value and the post-changed X-ray tube current value.

Abstract: A rotary electrical contact device includes a stationary member configured to be coupled to a base, and a rotatable member supported for rotation relative to the stationary member and defining a center opening. A raceway includes a plurality of axially spaced annular contact rings supported by one of the stationary member and the rotatable member. A blade tower includes a plurality of axially spaced blade assemblies and is supported by the other of the rotatable member and the stationary member. Each blade assembly includes a radially extending contact blade in electrical communication with one of the axial spaced contact rings of the raceway.

Abstract: A displacement and velocity based prospective cine CT (PDV CT) method is disclosed for starting image acquisition if the displacement and velocity are simultaneously within predetermined tolerances, thus essentially sorting 2D CT images in a five dimensional parameter space, where displacement and the sign of the velocity are used for the temporal sorting, replacing the use of either phase or displacement as the temporal parameter during retrospective sorting, with velocity as a separate parameter correlating to some parameter of the system, e.g. the airflow rate, making it possible to do the image sorting in real-time.

Abstract: A method is disclosed for production of computer-tomographic scans via a CT system of a patient during an intervention with an instrument. An X-ray tube is moved on a rotation plane around the patient in order to produce a beam cone, and a detector with a plurality of detector elements measuring the radiation intensity after passing through the patient. Computer-tomographic scans are reconstructed from the measured values in a computation unit. The central direction of the beams of the scanning beam cone is set at an angle to the intervention axis, and at least one slice plane which differs from the rotation plane of the beam cone is displayed on a display.

Abstract: An X-ray CT image reconstruction method includes turning a fan-shaped X-ray beam, which is thick and irradiated to a subject, about the subject, detecting projection data items concerning an X-ray beam, which is transmitted by the subject, with the X-ray beam turned by a plurality of successive angles of rotation, enhancing fan-beam data, which includes projection data items detected with the X-ray beam turned by the angles of rotation, so as to sharpen projection data contained in the fan-beam data and acquired along each projection line, producing parallel-beam data, which has values thereof defined along parallel projection lines, in relation to each angle of projection using the enhanced fan-beam data, and reconstructing an image using the parallel-beam data.

Abstract: An X-ray CT apparatus that achieves a higher quality of reconstructed CT images by preventing displacements of relative positions of the X-ray tube and the X-ray detector from occurring, including a front side rotation frame configured to mount at least one X-ray tube and at least one X-ray detector facing the X-ray tube, and a rear side rotation frame configured to mount rotation units other than the X-ray tube and the X-ray detector in order to access both sides of the gantry.

Abstract: A method for retrospective internal gating is provided. The method includes scanning a patient to obtain projection data, generating images from the projection data, generating a signal representing information regarding a physiological cycle of an object within the patient, specifying at least one target phase based on which the images can be sorted, and sorting the images based on the target phase within a cycle of motion of the object to generate at least one series of images.

Abstract: A computer tomography apparatus and method, a computer-readable medium and a program element are provided for examining a region of interest (ROI) of an object or patient in real-time. When only a region of interest is to be reconstructed, it is sufficient to rotate the radiation source and detector elements such that they cover a circular arc whose extension is less than ?+?, ? being the beam angle of the radiation source. This scanning range is called super-short-scan. Super-short-scans produce less data. Consequently image reconstruction is quicker which is very preferable for real-time CT. The CT data can furthermore be weighted in a manner that data detected at the end of a super-short-scan are weighted stronger than data detected at the beginning of a super-short-scan.

Abstract: A method, computed tomography (CT) system and computer-readable medium for reconstructing an image volume of an object scanned in helical mode. An embodiment of the method includes determining discrete focal lengths within an imaging plane of the reconstructed field of view comprising the image volume; generating a circular scan sinogram(s) for the discrete focal lengths by interpolating the helical views; selecting within a backprojection operation a circular scan sonogram(s), for one or more image points within the imaging plane, over one or more circular views. The method then includes using the selected circular scan sinogram(s), in the backprojection of the image points point(s) over the circular views view(s) and performing a backprojection for all the image points over all the circular views to generate a reconstructed image of the object.

Abstract: A control device pivots an X-ray arrangement repeatedly between two final angular positions about a pivot axis. Projections of an object arranged in the region of the pivot axis and moving iteratively are detected at a plurality of angular positions and supplied to the control device. The control device also receives a phase position referring to the object and assigns the phase position to each projection. A computer selects one or more projections whose phase position corresponds at least approximately to a reconstruction phase position. If the computer has selected one projection for an angular position, it determines this projection as a reconstruction projection. If the computer has selected a plurality of projections for an angular position, it detects the reconstruction projection using these projections. The computer then detects a three-dimensional reconstruction of the object based on the reconstruction projection.

Abstract: A method for estimating a diameter of an object of interest, includes extracting a sub-volume of voxels around a marker identifying a location of the object of interest, and determining a segmentation result identifying an edge of the object of interest by a reactive-diffusion method. The method further includes performing a boundary check on the segmentation result to determine whether the object of interest is solitary, estimating a diameter of the object of interest from the segmentation result upon determining the object of interest to be solitary, and extracting the object of interest by performing ellipsoid fit on the sub-volume and estimating a diameter of the object of interest upon determining the object of interest to be non-solitary.

Abstract: A physiological parameter monitor (44) monitors a cyclic physiological parameter and generates a cyclic parameter phase indicative signal. A radiation system (8) is disposed adjacent an examination region (18, 28) to generate transmission radiation data and emission radiation data. First and second sorting devices (48, 74) sort corresponding transmission and emission radiation data into transmission radiation data sets (50) and emission radiation data sets (78) corresponding to each of a plurality of the cyclic parameter phases. A data processor (60) reconstructs attenuation maps (62) from the transmission data for each of the plurality of cyclic parameter phases. An image processor (80) corrects the emission radiation data of each cyclic parameter phase with the attenuation map (62) of the same cyclic parameter phase and reconstructs the attenuation corrected emission data sets into an image representation for each cyclic parameter phase.

Abstract: In a device for contact-free transmission of electrical signals between two gantry parts of a computed tomography system that rotate relative to one another, at least one annular, circumferential transmitter element is mounted on one gantry part to transmit the electrical signals, and at least one receiver element to receive the signals emitted by the transmitter element is mounted on the other gantry part . The transmitter element is formed by a single conductor running on a surface, this conductor representing an electrical reference ground (zero potential). At least one dielectric immediately follows on the surface, and multiple conductive conductor structure pairs are executed in two mirror-image parts and are mounted on the at least one dielectric.

Abstract: A selectable mode of operation is disclosed for an X-ray computer tomograph for producing angiographical images. A patient accommodated on a couch is not moved relative to the measuring system in the z-direction, the entire area to be examined is irradiated at a prescribed first angle of rotation of the measuring system, and the X-ray radiation emerging from the area to be examined is detected isochronously using a matrix detector.

Abstract: A cargo security inspection method and system based on spiral scanning, the method including: spirally scanning an inspected object at a first precision to obtain the transmission projection data; judging whether there is a suspect area in the inspected area; scanning at least one slice of the suspect area at a second precision wherein the second precision is greater than the first precision; reconstructing a tomographic image of the at least one slice; and using the reconstructed tomographic image to judge whether there is any dangerous article in the suspect area.

Abstract: Methods and apparatus for an imaging system are provided. The imaging system includes a gantry having a stationary member coupled to a rotating member. The rotating member has an opened area proximate an axis about which the rotating member rotates. An x-ray source provided on the rotating member. An x-ray detector may be disposed on the rotating member and configured to receive x-rays from the x-ray source. A rotary transformer having circumferentially disposed primary and secondary windings may form part of a contactless power transfer system that rotates the rotatable portion of the gantry at very high speeds, the primary winding being disposed on the stationary member and the secondary winding being disposed on the rotating member.

Abstract: An X-ray CT device according to the present invention produces an X-ray beam of a cone shape in the direction of the body axis of a subject from an X-ray source, performs a helical scanning operation in accordance with the relative movement and relative rotational motion of the X-ray source and the subject, processes data that is collected by a data collecting unit, and reconstructs an image by back-projecting the processed data at a reconstruction processing unit. When the moving speed of the bed is defined, a system controlling unit determines the optimal collection condition for a two-dimensional array-type X-ray detector.

Abstract: It is an object of the present invention to eliminate windmill artifacts that inevitably occurs when a helical scan is performed with an X-ray CT system. To this end, the present invention is equipped with an X-ray source, and an X-ray detector having a plurality of detector elements arranged two-dimensionally, and disposed opposite to the X-ray source with a predetermined rotation center axis therebetween. The invention further includes reconstruction means for performing an arithmetic operation, in which two-dimensional projection data obtained based on X-ray detection data detected by the detector elements while rotating the X-ray source around the rotation center axis are back projected along a path different in a Z-axis direction extending along the rotation center axis from the X-ray path of the projection data, to reconstruct an image.