Abstract: An X-ray optical system for small angle scattering has a parabolic multilayer mirror and, so that switching to other X-ray incident optical systems for X-ray analysis can be easily performed. A parabolic multilayer mirror, an optical-path selecting slit device, a small-angle selecting slit device and a Soller slit are arranged between an X-ray source and a specimen-side slit. An X-ray beam having passed through the first aperture of an aperture slit plate is interrupted by the optical-path selecting slit. An X-ray beam having passed through the second aperture of the aperture slit plate is reflected at the reflecting surface of the multilayer mirror to become a parallel beam. This parallel beam passes through an aperture of the optical-path selecting slit device. The beam width is restricted by a narrow slit of the small-angle selecting slit device.

Abstract: An X-ray computed tomography apparatus includes a first X-ray tube configured to generate X-rays with which a subject to be examined is irradiated, a first X-ray detector configured to detect X-rays transmitted through the subject, a second X-ray tube which generates X-rays with which a treatment target of the subject is irradiated, a rotating mechanism which rotates the first X-ray tube, the first X-ray detector, and the second X-ray tube around the subject, a reconstructing unit configured to reconstruct an image on the basis of data detected by the first X-ray detector, and a support mechanism which supports the second X-ray tube. The central axis of X-rays from the second X-ray tube tilts with respect to a body axis of the subject. This makes it possible to reduce the dose on a portion other than a treatment target.

Abstract: A medical charged particle irradiation apparatus capable of irradiation from upward and horizontal directions and performing a preparing/ascertaining work without any separate device such as a moving capsule or the like comprising a patient's bed, on which a patient lies, a transport equipment for injecting and transporting charged particle beams toward the patient's bed, an irradiation field forming device for forming an irradiation field for the beams transported by the transport equipment, and a gantry provided to be rotatable about an axis of rotation, and wherein the irradiation field forming device is eccentrically arranged such that an axis of irradiation passes a position different from the axis of rotation, and the patient's bed is arranged on an opposite side of the transport equipment to a plane, which contains the axis of rotation and is substantially perpendicular to the axis of irradiation.

Abstract: A medical charged particle irradiation apparatus capable of irradiation from upward and horizontal directions and performing a preparing/ascertaining work without any separate device such as a moving capsule or the like comprising a patient's bed, on which a patient lies, a transport equipment for injecting and transporting charged particle beams toward the patient's bed, an irradiation field forming device for forming an irradiation field for the beams transported by the transport equipment, and a gantry provided to be rotatable about an axis of rotation, and wherein the irradiation field forming device is eccentrically arranged such that an axis of irradiation passes a position different from the axis of rotation, and the patient's bed is arranged on an opposite side of the transport equipment to a plane, which contains the axis of rotation and is substantially perpendicular to the axis of irradiation.

Abstract: A radiation diaphragm for an X-ray apparatus has an absorber element that can be swiveled around a swiveling axis for the variable limitation of a ray bundle. The swiveling axis is oriented transversely to the ray bundle. A swivel arm that can be swiveled around the swiveling axis and that carries the absorber element. The absorber element can comprise a curved shape. Such a radiation diaphragm allows an especially effective radiation dose limitation for the patient.

Abstract: A collimating device for controlling a radiation field of an X-ray radiated from an X-ray radiator. The device includes a plurality of first collimating leaves, a plurality of second collimating leaves, a beam generator, a detector, a memory, and a controller. The plurality of second collimating leaves oppose the first collimating leaves. The beam generator is configured to generate a beam. The beam emanates between the first collimating leaves and the second collimating leaves. The detector is configured to detect the beam. The memory is configured to store position information of each leaf of the first and second collimating leaves when the each leaf is determined to intersect the beam based on the detection. The controller is configured to position the each leaf based on the position information so as to control the radiation field.

Abstract: The invention is intended to shorten a positioning time required for forming an irradiation area with high accuracy using a number of leaf plates, and to reduce physical and mental burdens imposed on patients. A multi-leaf collimator comprises leaf plate driving body each including a plurality of movable leaf plates and provided respectively on one side and the other side, the plurality of leaf plates of the leaf plate driver on one side and the plurality of leaf plates of the leaf plate driver on the other side being disposed in an opposing relation to form an irradiation field of a radiation beam between the opposing leaf plates. Each of the leaf plate driving body includes a motor provided in common to the plurality of leaf plates. Driving force of the motor can be transmitted to the plurality of leaf plates at the same time through a pinion gear, upper and lower air cylinders, and upper and lower guides. Also, the driving force can be cut off selectively for each leaf plate.

Abstract: A collimator for X-ray apparatus has an aperture defined by the edges of four movable flexible shutters. Each shutter can be moved independently of the other shutters; thus, the position and the size of the aperture can be adjusted at will. The shutters are moved by winding them onto drums; each drum is driven by a stepping motor. Springs bias the shutters towards the closed position of the collimator.

Abstract: An adjustable collimator for reducing the emission of off-focus radiation and for use in selectively altering the size of an x-ray beam produced by an x-ray tube is disclosed. The collimator comprises a base member supporting a collimator plate that defines a first x-ray passing region. A radiation blocking member is operably attached to a moveable block that is disposed in the base member such that selective movement of the block causes the blocking member to obstruct and thereby reduce the size of the first region and create a smaller-dimensioned second region through which x-rays can pass.

Abstract: The invention relates to a collimator (1) for limiting a bundle of high-energy rays (2), which is emitted by a substantially point-like radiation source (3) and directed towards a treatment object (20) and used in particular for the stereotactic conformation radiotherapy of tumors. According to the invention the collimator (1) comprises a plurality of diaphragm leaves (4, 4′) which are arranged opposite each other and which are made of a radiation-absorbing material and which, by means of drive mechanisms, can be moved into the optical path in such a way that the contours and/or exposure period of said optical path can be freely defined, the front edges (5, 5′) of the diaphragm leaves (4, 4′) being parallel to the optical path at all times.

Abstract: In order to provide an aperture position adjusting mechanism in an X-ray CT system with low cost and high accuracy to enable stable reconstruction of X-ray tomographic images, a first shaft (23) is provided with a bore (23a) at a position offset from a center axis, and is rotatably supported by a base plate (20) orthogonally to a pair of rails (21a, 21b). A second shaft (25) is received and is rotatably supported within the bore (23a) through the first shaft (23). The aperture (6) is moved along the rails (21a, 21b) as the second shaft (25) is eccentrically rotated by a motor (7) and, following the eccentric rotation and in a direction opposite to that of the rotation, the first shaft (23) is eccentrically rotated around the center axis of the bore (23a).

Abstract: A contour collimator for radiation therapy has a plurality of diaphragm elements that are movable with respect to each other by means of drive units. The diaphragm elements of the invention are supported only on the side near the drive units for ease of movement. This allows larger contour collimators to be constructed having relatively heavy diaphragm elements while retaining relatively small motors.

Abstract: A system and method of the present invention for controlling radiation delivery from a radiation source to an object are disclosed. The method generally includes defining a field on the object for radiation delivery. The field includes a plurality of cells, each having a defined treatment intensity level. The cells are grouped to form a matrix having at least one dimension approximately equal to a width of a collimator leaf capable of blocking radiation emitted from the radiation source. The method further includes decomposing the matrix into orthogonal matrices and optimizing delivery of the radiation by selecting a combination of orthogonal matrices to minimize junction effects.

Abstract: A radiation imaging system comprises a movable radiation source adapted to be disposed in a plurality of respective radiation source positions; a radiation detector and a collimator assembly configured to displace a collimator in a plurality of respective collimator positions, each of the collimator positions being coordinated with at least one of the radiation source positions such that a radiation beam emanating from the radiation source is collimated to limit radiation incident on the detector to a predetermined exposure area. Another radiation imaging system comprises a movable radiation source; a radiation detector; and a collimator comprising an adjustable geometry aperture assembly configured such that an adjustment of the aperture geometry is synchronized with the movement of the radiation source and coordinated with the radiation source position so as to limit the incident radiation to a predetermined exposure area at the detector.

Abstract: A method an arrangement in an x-ray imaging apparatus (10), includes at least one x-ray source (11), a collimator (42, 52, 62a, 62b, 72) and a detcetor (43, 73); the arrangement is arranged for providing a variable exposure of the dector (43, 73) to x-ray radiation from the x-ray source (10) through slots (45, 55, 65a, 65b, 75) on the collimator (42, 52, 62a, 62b, 72). The arrangement comprises at least one of the collimator (42, 52, 62a, 62b, 72) or registering means (43, 73), which are arranged moveable relative each other to vary number of x-rays registered by the dector.

Abstract: An x-ray shielding system includes a beam controller configured to surround an x-ray source and includes a detector shield configured to position behind an x-ray detector. The beam controller includes a source shield and an aperture. The source shield and the detector shield are adapted to block x-rays, and the aperture is adapted to transmit x-rays. A shielded digital radiographic inspection system includes the x-ray source and the beam controller surrounding the x-ray source. The beam controller includes the source shield and the aperture. The aperture is configured to rotate around the x-ray source. The inspection system further includes a digital x-ray detector positioned radially outward from the x-ray source and facing the aperture. The digital x-ray detector is configured to be movable along an orbit around the x-ray source. The inspection system further includes the detector shield configured to be movable with and positioned behind the digital x-ray detector.

Abstract: A radiation diaphragm for an X-ray apparatus has an absorber element that is seated so as to be eccentrically rotatable around a rotational axis oriented in its longitudinal direction, so that the size of the ray beam is variable by means of a rotary motion of the absorber element. The absorber element is fashioned, for example, as a drum, a roller or a cylinder. The radiation diaphragm can be implemented especially rugged and is suited for higher rotational speeds in a computed tomography apparatus.

Abstract: A method for defining an extended field area of an intensity map for use in delivering radiation from a radiation source to an object with a multi-leaf collimator is disclosed. The multi-leaf collimator includes a plurality of leaves operable to travel in a first direction and rotatable such that the leaves are operable to travel in a second direction extending generally orthogonal to the first direction. The method includes defining a central square area having dimensions approximately equal to two times an over travel margin of the multi-leaf collimator and defining four edge margins each extending from a side of the central square and having dimensions approximately equal to two times an over travel margin of the multi-leaf collimator along an edge adjacent to the central square and half the number of leaves within the multi-leaf collimator times leaf width minus half the central square dimension.

Abstract: An X-ray tube (3) is rotated about its focal point along a plane perpendicular to a body axis of a patient by an X-ray tube rotation driver and thus the X-ray irradiation field moves. When the side of the X-ray irradiation field reaches an edge detector (6a) in the edge part of the flat panel detector, the edge detector detects X-ray and provides a signal to a controller. The controller controls the X-ray limiting device (4a) to move shield blades thereof to limit the range of the X-ray irradiation field. The above structure makes it possible to move the center of the X-ray irradiation field without moving the patient and also to prevent the X-ray irradiation field from going outside of the flat panel detector.

Abstract: A method for calibration and/or quality assurance of nuclear medicine imaging, in which functional information of the organs to be studied is achieved by inserting radioactive solution emitting detectable radiation in the organs of a phantom simulating the organs to be studied and by detecting the radiation. The filling and emptying of the organs of the phantom to be studied is simulated by regulation of the detectable radiation from the phantom. The organs to be simulated by the phantom are in form of containers filled with radioactive solution, the apparatus further comprising movable isolating parts, like steel plates, between the containers and the gamma camera to isolate radiation from the containers to the camera. The invention is also concerned with an arrangement comprising the apparatus of the invention and a gamma camera.

Abstract: An x-ray diffraction apparatus for qualitatively analyzing a sample uses a fixed or variable divergence slit to irradiate a portion of its surface and intensity data are collected at different angles of diffraction. When measured data thus obtained are compared with reference data for the qualitative analysis, the measured data, the reference data or both of these data are corrected in part according to whether the reference data were taken by measurements using a fixed or variable divergence slit such that the comparison can be carried out on the same intensity level and the qualitative analysis can be carried out more accurately.

Abstract: The present invention relates to a method an arrangement in an x-ray imaging apparatus (10), comprising at least one x-ray source (11), a collimator (42, 52, 62a, 62b, 72) and a registering means (43, 73), the arrangement is arranged for providing a variable exposure of said registering means (43, 73) to x-ray radiation from said x-ray source (10) through slots (45, 55, 65a, 65b, 75) on said collimator (42, 52, 62a, 62b, 72). Said arrangement comprises at least one of said collimator (42, 52, 62a, 62b, 72) or registering means (43, 73), which are arranged moveable relative each other to vary number of x-rays registered by said registering means.

Abstract: In order to control a collimator so that an X-ray impingement position on an X-ray detector is kept constant, an error of the impingement position of a fan-shaped beam (400) in the direction of side-by-side arrangement of a plurality of detector element rows in a detector element array (24) is detected (101), and the collimator is controlled (103) based on the detected error so that the impingement position of the fan-shaped beam is kept at a constant position.

Abstract: A system and method for automatically collimating X-rays. A digital X-ray system (100) includes a generator (108), a sensor unit (110), a control station (112), and a preview monitor (114). The generator (108) generates X-ray radiation that is captured by the sensor unit (110) as a digital image and transmitted to the control station (112). The captured image is displayed on the preview monitor (114). The generator (108) includes a collimator (212) that collimates the generated radiation into a primary beam of X-rays. The size and shape of the primary beam can be adjusted by modifying collimation parameters. A short duration beam of X-rays is generated by the generator (108) and captured (414) by the sensor unit (110). This step is repeated as necessary or desired. The resulting digital images are analyzed (418) by the control station (112) to calculate a calibration coefficient. Another short duration beam of X-rays is generated and a reference image is captured (514).

Abstract: An x-ray apparatus has an x-ray source and an x-ray receiver, the x-ray source being adjustable relative to a subject and emitting x-rays in the direction toward the x-ray receiver during the course of radiological exposures of the subject. The x-ray apparatus has an arrangement in the beam path of the x-rays for influencing the shape and/or the intensity profile of the x-ray beam, and this arrangement is dynamically adjustable during radiological exposures of the subject for influencing the shape and/or the intensity profile of the x-rays.

Abstract: A method for acquiring a radiographic image of an elongated object, comprising: positioning an elongated object between a source of x-rays and a digital image capture device having an imaging dimension which is less than a like dimension of said elongated object; wherein said image source is stationary and said source projects an x-ray pattern which encompasses said elongated object; moving said digital image capture device in a direction parallel to said known imaging dimension to sequential contiguous stationary positions to acquire a sequence of radiographic images of said elongated object; and moving an assembly of x-ray opaque material which is positioned between said source of x-rays and said elongated object, and which has an opening for allowing passage of x-rays, such that said opening is synchronized with the movement of said digital image capture device to facilitate acquisition of said sequence of radiographic images at said stationary positions.

Abstract: An injection molded anti-scatter grid is fabricated from an engineered thermoplastic to form a focused x-ray absorbent framework defining a plurality of inter-spaces. The engineered thermoplastic has higher yield strength than conventional anti-scatter grid fabrication materials, which produces a structurally rigid grid that renders conventional fiber-like inter-space material unnecessary, and further allows the grid to be flexed in one or more directions to change an effective focal length of the grid. The engineered thermoplastic is loaded with high density particles in order to be x-ray absorbent, while still maintaining desired structural properties.

Abstract: Aspects for verifying an accessory beam limiting device position for a radiotherapy treatment session are described. Included in a system aspect is a radiotherapy treatment device, the radiotherapy treatment device including an accessory holder. A beam limiting device for establishing a treatment area, the beam limiting device held in the accessory holder, is also included, along with a first controller for controlling the radiotherapy device and performing a treatment plan. A second controller positions the beam limiting device according to the treatment plan, wherein performance of the treatment plan by the first controller depends on provision of an accessory code to the first controller. The accessory code includes a resistor-pair combination value.

Abstract: An assembly including a base and first and second spaced-apart shafts secured to the base and extending generally perpendicular to an elongated aperture of the base. A carrier includes a first support member slidingly receiving the first shaft, a second support member receiving the second shaft, and an elongated opening extending between the support members and generally perpendicular to the shafts. The elongated opening of the carrier is for aligning with the aperture of the base and an elongated slit of a collimator supported on the carrier for passage of an x-ray beam therethrough. A backlash-resistant nut assembly is threadingly received on a threaded portion of the second shaft and secured to the second support member.

Abstract: The present disclosure provides an adjustable collimator for collimating a beam of energy emitted from a focal spot of a beam source. The collimator is particularly intended for collimating an x-ray beam of a computed tomography scanner after the x-ray beam has passed through a patient being scanned. The collimator includes two elongated parallel plates arranged side by side to define a collimating slit between the plates. At least one of the plates is movably relative to the other plate for varying a width of the collimating slit. The collimator also includes a movable cam operatively arranged with respect to the at least one movable plate such that movement of the cam in a first direction causes the width of the collimating slit to increase, while movement of the cam in a second direction causes the width of the collimating slit to decrease.

Abstract: The shutters (2) in an X-ray device which include at least a radiation source (1), a diaphragm device (8) with shutters (2) and a recording (3) and image processing unit (4), are provided with hole and/or edge patterns (11-14) which reproduce non-anatomical patterns in the radiation image; the shutter edges (15) are detected in the radiation image in the image processing unit on the basis of such patterns, so that only the directly irradiated part of the patient is displayed.

Abstract: In apparatus for radiation analysis, for example, X-ray spectrometers, the aperture angle of the analysing radiation beam 45 is often desired to vary during the measuring process. The aperture angle of the radiation beam is determined, for example, by the length of the collimating elements 46, 60 in the collimator. In accordance with the invention, this is achieved by displacing or rotating the collimator through the radiation beam 45, so that the collimating element length L exposed to the radiation beam can be varied in consequence. A collimator comprising rectangular plates 46 (Soller collimator) can be rotated around a shaft 50 perpendicular to the plates, or a collimator comprising X-ray fibres 60 can be arranged with varying fibre lengths and displace them through the radiation beam transversely to the longitudinal direction of the fibres.

Abstract: For the purpose of reconstructing a plurality of X-ray tomographic images having a plurality of practical slice thicknesses while reducing the number of X-ray detector arrays and simplifying configuration, X-rays generated by an X-ray tube 4 are emitted via a slit 15 of a collimator 6 toward a detector 8 disposed opposite to the X-ray tube 4; the length (width) of the collimator 6's slit 15 in the D1 direction and the position of the collimator 6 in the D1 direction are adjustable; the detector 8 is comprised of four X-ray detector arrays; and the widths of the two outer X-ray detector arrays in the D1 direction are larger than the widths of the two center X-ray detector arrays.

Abstract: Apparatus for guiding X-rays from a radiation source to a measurement object (16) having at least two reflecting areas (18) forming a slit.

Abstract: One embodiment of the present invention is a method for constructing a post-patient collimator for a computed tomographic (CT) imaging system, the method including steps of: edge welding collimator plates to a top rail using at least one directed energy beam welder; and edge welding the collimator plates to a bottom rail, using the at least one directed energy beam welder.

Abstract: A collimator having slits of varied widths, wherein each slit includes a curved side profile having a common axis of curvature for providing a cross-section of an emitted beam of energy with a substantially uniform width when the common axis of curvature of the slit intersects a focal spot of a source of the beam. The collimator is curved about a rotation axis substantially normal to the common axis of curvature, such that rotating the collimator about the rotation axis will sequentially position the slits to collimate the emitted beam.

Abstract: Collimator apparatus is provided for an X-ray imaging system comprising an X-ray tube disposed to project an X-ray beam, and a detector spaced apart from the X-ray tube for receiving X-rays of the beam within an Active Imaging Area (AIA). The apparatus comprises a first collimator positioned along the path of the beam, the first collimator being vertically adjustable, and being operable to symmetrically collimate the beam. The apparatus further comprises a second collimating device positioned between the first collimator and the detector. The second collimating device limits the uppermost rays of the symmetrically collimated beam which reach the detector to a predetermined upper boundary. Thus, the second collimating device serves to fix the upper edge of the AIA on the detector.

Abstract: A collimator system including a plurality of revolvable plates stacked one above another, the plates being constructed of a material substantially impervious to passage therethrough of radiation in a predetermined range of wavelengths, and at least one collimator aperture formed in each of the plates.

Abstract: The invention relates to a method of setting a position of an object of measurement in layer thickness measurement by X-ray fluorescence in which a beam of an optical recording device is projected into the beam of the X-radiation and in which the surface of the object of measurement is recorded and output as an image comprising a number of image points, with the distance between the surface and the collimator being changed by an absolute amount of a path of movement, with changes in brightness of the image points being recorded in at least one measuring plane during the at least one change of the distance between the surface and the collimator, with the maximum of the difference in brightness of the image points of an image being ascertained after the at least one change of the absolute amount of the distance, and with the distance between the collimator and the object of measurement being set to the position of the ascertained maximum of the difference in brightness.

Abstract: A backlash-resistant sliding assembly for supporting a collimator. The assembly includes a base having an elongated aperture for passage of an x-ray beam therethrough, a first shaft secured to the base and extending generally perpendicular to the aperture of the base, a second shaft spaced from, and extending substantially parallel to the first shaft, the second shaft rotatably secured to the base and having a threaded portion and at least one non-threaded portion. The assembly also includes a carrier adapted to support a collimator having at least one elongated slit, the carrier including a first support member having a bore slidingly receiving the first shaft, a second support member having a bore receiving the non-threaded portion of the second shaft, and an elongated opening extending between the support members and generally perpendicular to the shafts.

Abstract: Collimation device of the type intended to direct an energy beam in a given direction and at a given solid angle, the collimation device being capable of being installed on output of an energy beam generating means and of being connected to a control unit. The collimation device includes means for testing operation of the assembly formed by the energy beam generating means, the collimation device 1 and the control unit.

Abstract: The invention relates to an X-ray examination apparatus which includes an X-ray source, an X-ray detector, absorption means arranged between the X-ray source and the X-ray detector, a control unit for adjusting the absorption degree of the absorption means, an image processing unit and a display unit. In order to perform an automatic adjustment of the absorption means, the absorption degree therein is optimized in dependence on user-specific parameters (r) and/or apparatus-specific parameters (s) and/or structure parameters (C) and/or parameters (r) classifying the subject matter of the image.

Abstract: A multileaf collimator for use in a radiation system providing a radiation beam in a given beam direction, including a first layer of a plurality of radiation blocking leaves, the leaves being arranged adjacent one another so as to form two opposed rows of adjacently positioned leaves and being movable in a longitudinal direction (Y) which is generally transverse to the beam direction, defining a radiation beam shaping field between the opposed ends of the leaves, a second layer of a plurality of radiation blocking leave, the leaves of the second layer being arraigned adjacent one another as to form two opposed rows of adjacently positioned leaves and being movable in a cross-over direction (X) which is generally transverse to the beam direction and angled with respect to the longitudinal direction (Y), defining a radiation beam shaping field between the opposed ends of the leaves of the second layer.

Abstract: A beam limiting apparatus is provided for reducing the amount of off-focus radiation in the image-forming beam emitted from an x-ray tube assembly. The x-ray tube assembly has a housing with an x-ray port for the passage of x-rays therethrough, a mounting boss defining the x-ray port, an x-ray tube mounted within the housing and defining a glass envelope, an anode mounted within the glass envelope, and a cathode spaced relative to the anode within the glass envelope. A peripheral flange of the beam limiting apparatus is mountable to the mounting boss of the x-ray tube housing, and a radiation-absorbing body of the beam limiting apparatus projects downwardly from the peripheral flange through the x-ray port.

Abstract: The invention relates to an X-ray examination apparatus which includes an X-ray source and a diaphragm unit which is connected to the X-ray source and is provided with shutters for limiting a radiation cone beam emanating from the focal spot of the X-ray source, and also includes a light source for generating a light cone beam which traverses the shutters via a mirror. When the dimensions of the light-emitting parts of the light source are significantly larger than the focal spot, the irradiation field irradiated by the radiation cone beam is smaller than the illuminated field illuminated by the light cone beam. In order to match the irradiation field with the illuminated field, the shutters are provided with correction shutters which are transparent to X-rays but impervious to light and limit the light cone beam.

Abstract: A drive assembly for a collimator of an X-ray imaging device includes a carrier which is adapted for translation in the z-direction along two parallel shafts. One of the shafts is coupled to a driver, such as a motor, by a backlash-resistant nut assembly.

Abstract: Methods and apparatus for dose reduction in a computed tomography (CT) system are described. In one embodiment, the CT system includes a pre-patient collimator and a configurable multislice detector array. The pre-patient collimator includes a plurality of eccentric cams and a filtration device for altering the x-ray beam radiated from a x-ray source. The eccentric cams are positioned to collimate the x-ray beam and may be independently positioned to provide z-axis correction of the x-ray beam. The filtration device includes a plurality of filters for altering the x-ray beam. In operation, an operator selects the type of test and the quantity and thickness of the slices. After altering the detector and collimator configuration, slice data for each slice is gathered.

Abstract: A dual beam modulator (10) includes a rotatable cylinder (12) having annular walls (14, 15) and a set of a plurality of discrete chordal passages (18) extending through the walls between opposing holes in the outer surface of cylinder walls (14, 15). Each of the passages (18) is spaced radially about each of the walls (14, 15) and longitudinally in the direction of the longitudinal axis of the cylinder (12) for producing, in response to an incident fan beam of radiation (30), a series of discrete pencil beams (28) as the cylinder (12) rotates. The cylinder (12) further has reduced radius sections (16, 17) on the outer surface of the walls (14, 15) for periodically passing the incident fan beam (30) alternately with the series of pencil beams (28) as the cylinder (12) rotates.

Abstract: A multileaf collimator (12) for use in a radiation system (10) providing a radiation beam (20) in a given beam direction, including a first layer (30) of a plurality of radiation blocking leaves (32), the leaves (32) being arranged adjacent one another so as to form two opposed rows of adjacently positioned leaves (32) and being movable in a longitudinal direction (Y) (34) which is generally traverse to the beam direction so as to define a radiation beam shaping field (36) between the opposed ends of the leaves (32), a second layer (40) of a plurality of radiation blocking leaves (42), the leaves (42) of the second layer (40) being arranged adjacent one another so as to form two opposed rows of adjacently positioned leaves (42) and being movable in a cross-over direction (X) (44) which is generally traverse to the beam direction and angled with respect to the longitudinal direction (Y) (34) so as to define a radiation beam shaping field (46) between the opposed ends of the leaves (42) of the second layer (40)

Abstract: In a computed tomography apparatus, and a method for operating same, for obtaining cardiac images, a spiral scan of a measurement volume containing a patient's heart is conducted, the production of the scanning data during the spiral scanning being synchronized with an ECG signal from the patient, in order to produce a graphic representation of the examination volume, and thus an image of the patient's heart. The ECG signal is employed to control the generation of the data during the spiral scanning at phase of the cardiac cycle wherein minimum movement of the heart takes place. The chronological correlation between the recording of the scanning data and the ECG signal is fixed, so that within each number of successive time intervals, a dataset is obtained completely within that time interval. The datasets from the successive time intervals are then combined to produce an image of the heart.