US3829701A - Radiation collimator - Google Patents

Radiation collimator Download PDF

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Publication number
US3829701A
US3829701A US00327644A US32764473A US3829701A US 3829701 A US3829701 A US 3829701A US 00327644 A US00327644 A US 00327644A US 32764473 A US32764473 A US 32764473A US 3829701 A US3829701 A US 3829701A
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Prior art keywords
vanes
radiation
diaphragm
beam path
focus
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Expired - Lifetime
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US00327644A
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English (en)
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M Hura
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Philips Nuclear Medicine Inc
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Picker Corp
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Publication date
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Priority to US00327644A priority Critical patent/US3829701A/en
Priority to CA191,252A priority patent/CA991760A/en
Priority to NL7401105A priority patent/NL7401105A/xx
Priority to JP49011728A priority patent/JPS49107485A/ja
Priority to FR7402925A priority patent/FR2215777A1/fr
Priority to DE2404194A priority patent/DE2404194A1/de
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Publication of US3829701A publication Critical patent/US3829701A/en
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B42/00—Obtaining records using waves other than optical waves; Visualisation of such records by using optical means
    • G03B42/02—Obtaining records using waves other than optical waves; Visualisation of such records by using optical means using X-rays
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K1/00—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating
    • G21K1/02—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating using diaphragms, collimators
    • G21K1/04—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating using diaphragms, collimators using variable diaphragms, shutters, choppers

Definitions

  • ABSTRACT A radiation collimator including opposed pairs of movable off-focus radiation diaphragms comprising interleaved arrays of plates supported centrally on stems.
  • the stems of each opposed pair of diaphragms are pivotally supported and coupled together for concurrent movement toward and away from each other.
  • Each opposed pair of off-focus diaphragms is interconnected to corresponding on focus diaphragms movably mounted for rectangularly delineating the perimeter of the primary beam.
  • the off-focus diaphragms extend to within very close proximity of the radiation source to block off-focus radiation.
  • the present invention relates generally to X-ray apparatus and more particularly to 'a collimator structure designed to block undesired off-focus radiation.
  • Radiation scatter is produced when the primary radiation beam strikes a patient or object and is diffracted. If the size of the X-ray beam is larger than required to accommodate a particular area under investigation, the X-radiation striking areas of the subject around the area of investigation will produce an unnecessary amount of radiation scatter which has the effect of fogging the radiograph thereby producing a poor image.
  • collimators are used to delineate an X-ray beam of the desired size.
  • these collimators generally include two pairs of relatively movable diaphragms which delineate an X-ray beam of rectangular cross section.
  • Thesediaphragms when properly adjusted, will minimize scatter, but by no means elimate all causes of blurred radiographs.
  • the X-ray beam is emitted from a very small area on an X-ray tube anode known as the focal spot. Theoretically, this spot can be so small and bombardment of it with electrons so precise that the beam is emitted in a precise and regular conical pattern of onfocus radiation.
  • the spot is a larger area than a theoretically optimized spot and an X-ray tube emits a penumbra or band of so-called offfocus radiation from areas around the spot.
  • the collimator diaphragms are typically spaced from about four to about eleven inches from the X-ray tube focal spot. With this spacing, some off-focus radiation comingles with the on-focus radiation with a resultant blurring of the radiograph.
  • Mechanisms for adjusting the diaphragms are typically positioned, speaking transversely of the beam, between the diaphragms and the focal spot.
  • the mechanisms are offset from the primary beam so that they do not interfere with it.
  • the off-focus radiation is not necessarily absorbed by the diaphragms provided to delineate the beam size, but rather may spread outwardly from the theoretical beam. To the extent that radiation which comingles with the primary beam can cause serious degradation in radiographic quality.
  • the mechanism for controlling the off-focus radiation should not interfere with the desired on-focus radiation in the primary beam, but at the same time should absorb all radiation around the primary beam;
  • the off-focus device should desirably be adjustable with the onfocus diaphragms of the collimator;
  • Each of the off-focus diaphragm structures includes an array of vanes supported by a stem at axially spaced positions along the X-ray beam path.
  • the vanes of each diaphragm structure are interleaved on a one-to-one basis with the vanes of two adjacent diaphragm structures.
  • the supporting stems are pivotally mounted such that the vanes of one pair of diaphragm structures are movable inwardly and outwardly of the vanes of the other pair of diaphragm structures.
  • the inner edges of the vanes are of straight-line configuration and positioned such that the diaphragm structures cooperate with the on-focus diaphragms to rectangularly collimate the beam.
  • One vane of each of the diaphragm structures hereinafter called the upper vane, extends into very close proximity to the output window of the X-ray tube.
  • Others of the vanes hereinafter called the lower vanes, are spaced along the beam path and define progressively larger rectangular apertures.
  • the sides of the vanes facing toward the X -,ray beam are inclined relative to the beam path to prevent radiation scatter.
  • the inner side inclination is such that the upper surface of each vane extends inwardly toward the beam path a greater distance than the lower surface.
  • the upper vane of each off-focus diaphragm structure is cocked relative to its supporting stem in order to keep the inner, beam delineating vane edge at a relatively constant distance from the output window of the X-ray tube as the diaphragm pivots inwardly and outwardly.
  • the vanes have curved outer sides which give the assembled off-focus collimation system a generally circular cross section.
  • the upper vanes are of smaller crosssectional area than are the lower vanes.
  • the lower vanes increase in cross-sectional area the farther removed they are from the X-ray source. Accordingly, the assembled off-focus system has a generally conical outer appearance and is of minimal size in regions adjacent the X-ray source.
  • the interleaved vanes have been shown to be effective to block off-focus radiation without substantial radiation leakage.
  • the pivotal mounting of the supporting stems at positions removed from the X-ray source provides a construction wherein substantially only the effective area of the vanes themselves extend into regions adjacent the X-ray tube, while the linkages which connect with the on-focus diaphragms to effect concurthe accompanying drawings.
  • FIG. 1 is a partially schematic cross-sectional view of a radiation collimator constructed in accordance with the present invention and mounted on an X-ray tube housing;
  • FIG. 2 is a partially schematic cross-sectional view as seen fromthe plane generally indicated by the broken line 22 in FIG. 1;
  • FIGS. 3 and 4 are schematic illustrations of the offfocus radiation problem and illustrating how the present invention operates to greatly reduce off-focus radiation;
  • FIG. 5 is an enlarged top plan view of the off-focus collimation portion of the collimator of FIGS. 1 and 2;
  • FIG. 6 is a side-elevational view of the mechanism shown in FIG. 5 on the same scale as FIG. 5;
  • FIGS. 7, 8 and 9 are enlarged side, end and top plan views of one of the diaphragm structures incorporated in the mechanism of FIGS. 5 and 6, FIG. 7 being enlarged to a greater degree than are FIGS. 8 and 9.
  • an X-ray apparatus including an X-ray tube housing 10 which supports and houses an X-ray tube 11.
  • the X-ray tube 11 has an anode 12.
  • the anode 12 includes a small area known as a focal spot 13 which is bombarded with electrons to cause the emission of X-radiation along a conical beam path 14.
  • a collimator 20 is supported by the tube housing 10 around the beam path 14.
  • the collimator 20 delineates the perimeter of the beam to a rectangular cross section.
  • the collimator 20 includes a housing structure 21 defining spaced input and output ends 22, 23.
  • Opposed pairs of diaphragm plates 24 are supported on pivotally mounted arms. The arms are mounted in the collimator housing 21 for delineating the perimeter of the X-ray beam.
  • the diaphragm arrangement 24 is of the type disclosed in the referenced patent, and will be described in greater detail.
  • an off-focus collimation system 25 is interposed be-' tween the diaphragm arrangement 24 and the X-ray tube 11.
  • the offfocus collimation system includes two pairs of movable diaphragm structures which interconnect with the diaphragm arrangement 24.
  • the off-focus collimation system 25 cooperates with the diaphragm arrangement 24 to block off-focus radiation.
  • the diaphragm arrangement 24 comprises two pairs of upper diaphragm plates 30, 31 and 32, 33 and two pairs of lower diaphragm plates 34, 35 and 36, 37.
  • the upper diaphragm plates 30, 31, 32, 33 are supported, respectively, by arms 40, 41, 42, 43.
  • the lower diaphragm plates 34, 35, 36, 37 are supported, respectively, by arms 44, 45, 46, 47.
  • the arms 40, 41, 42, 43, 44, 45, 46, 47 are pivotally mounted by stub shafts 50, 51, 52, 53, 54, 55, 56, 57 which in turn carry gears 60, 61, 62, 63, 64, 65, 66, 67.
  • the gears 60, 61, 64, 65 are meshed as shown in FIG.
  • the gears 62, 63, 66, 67 are meshed as shown in FIG. 3 to provide concurrent movement of the diaphragm plates 32, 33, 36', 37.
  • the gear 65 rotates clockwise as seen in FIG. I when the diaphragm plates 30, 31, 34, 35 move toward each other, and counterclockwise as these diaphragms plates move apart.
  • the gear 67 rotates clockwise as seen in FIG. 2 when the diaphragm plates 32, 33, 36, 37 move toward each other, and counterclockwise as these diaphragm plates move apart.
  • the off-focus collimation system 25 makes connection with the gears 65, 67 in order to provide for concurrent movement of the off-focus diaphragms and the diaphragms 30-37. These connections include projec-
  • the off-focus collimation system 25 principally includes two pairs of diaphragm structures 80, 81 and 82, 83.
  • the diaphragm structures 80, 81, 82, 83 are pivotally mounted on pairs of stub-shafts 90, 91, 92, 93
  • gears 100, 101, 102, "103 which also respectively mount gears 100, 101, 102, "103.
  • the gears 100, 101 are meshed to effect concurrent movement of the diaphragm structures 80, 81 while the gearsl02, 103 are meshed to effect concurrent movement of the diaphragm structures 82, 83.
  • control lever 72 connects respectively with one of the stub shafts 90 while the control lever 73 connects with one of the stub shafts 93.
  • the stub shafts 90, 93 pivotally mount the control levers 72, 73 to interconnect the off-focus diaphragm structures80, 81 for concurrent movement with the diaphragms 30, 31, 34, 35, and the off-focus diaphragm structures 82, 83 for concurrent movement with the diaphragms 32, 33, 36, 37.
  • Each of the diaphragm structures 80, 81, 82, 83 comprises an array of vanes supported on a centrally located'stem.
  • the diaphragm structure 82 is-shown in greater detail as including an array of three vanes .84, 85, 86 supported in cantilever fashion from an integrally formed, centrally located stem 87.
  • the stem 87 is provided with a mounting flange 88.
  • a U-shaped bracket 95 is rigidly secured near the distal ends of its legs to the stub shafts 93, and is fastened by means of threaded fasteners 96. to the mounting flange 88.
  • the vanes 84, 85, 86 are bounded by planar inner sides84a, 85a, 86a and curved outer sides 84b, 85b, 86b.
  • the inner sides 84a, 85a, 86a cooperate withthe upper surfaces 84c, 85c, 86c of the vanes 84, 85, 86 to define beam delineating edges 84d, 85d, 86d.
  • the inner sides 84a, 85a, 86a are inclined relative to the beam path to prevent their being struck by radiation in such 1 fashion as would produce scatter.
  • the beam delineating edges 84d, 85d, 86d cooperate with corresponding beam delineating edges on the diaphragm structures 80, 81, 82, 83 to delineate the beam perimeterto a rectangular cross-section, as best seen in the top view of FIG. 5.
  • the curvedouter sides 84b, 85b, 86b and the corresponding outer sides of the vanes of the diaphragm structures 80, 81, 82, 83 minimize the area occupied by the diaphragm structures to permit their extension into the X-ray tube housing 10 into close proximity to the X-ray tube 11.
  • the vanes on the opposed pairs of diaphragm structures 80, 81, and 82, 83 are arranged to interleave as shown in FIGS. 1, 2 and 6. Specif cally, the vanes of the diaphragm structures 80, 81 underlie the correspond-.
  • the upper vanes of allof the diaphragm structures 80, 81, 82, 83 are cocked at an angle relative to their respective supporting stems in order to keep the inner beam delineating edges, e.g. edge 84d, at a substantially constant, minimal distance from the output window of the X-ray tube-As the diaphragm structures are pivoted inwardly and outwardly, the cocked upper vanes keep their beam delineating inneredges in close proximity to the X-ray tube window.
  • the diaphragm arrangement 24 principally serves to delineate the perimeter of thebeam of onfocus radiation which emanates from the anode focal spot 13 confine the on-focus radiation to a selected examination area 15.
  • Off-focus radiation emanating from anode locations spaced from the focal spot 13 can pass between the plates of the diaphragm arrangement 24 as shown in FIG. 3 so as to flood an area 16 which includes, but is substantially larger than, the examination area-15.
  • the off-focus radiation which falls outside the examination area results in an undesirable and entirely useless exposure of the patient to radiation.
  • the offfocus radiation which falls within the examination area 15 tends to overexpose radiographs and to blur the images thereon.
  • the off-focus collimation system 25 is provided having movable interleaved vanes which, as described, extend within close proximity of the X-ray tube to block off-focus radiation.
  • the vanes of the offfocus collimation system 25 confine the X-ray beam to one including on-focus radiation from the focal point 13, and a bare minimum of off-focus radiation.
  • This arrangement not only substantially confines the off-focus radiation area 16 to that of the examination area 15, but also greatly reduces the amount of off-focus radiation which falls within the examination area 15. Accordingly, the patient is exposed to less radiation, and the resulting radiograph has a sharper and more read able image.
  • a radiation collimator comprising, in combination;
  • an X-ray source for directing a beam of X- radiation along a beam path
  • on-focus diaphragm means for rectangularly delineating the beam
  • each of said diaphragm structures including a plurality of vanes supported at locations spaced longitudinally along the beam path and being movable as a unit toward and away from the beam path;
  • vanes of one pair of diaphragm structures being interleaved with the vanes of the other pair of diaphragm structures and vbeing movable in- 7 wardly and outwardly thereof independently of the position of said other pair of diaphragm structures.
  • each of said diaphragm structures further includes a supporting stem extending generally axially along the beam path and mounting said vanes;
  • said stem being movable mounted for moving said vanes transversely of the beam path.
  • said stems are pivotally mounted about axes spaced from said X-ray source;
  • vanes are mounted on said stems at locations intermediatesaid axes and said source.
  • a radiation collimator for collimating a radiation beam emanating from the focal point of a radiation source and traversing a beam path comprising:
  • a. diaphragm means movably positioned along the beam path for delineating'the perimeter of the beam to a first cross-sectionalsize and configuration
  • off-focus radiation collimation means positioned between said diaphragm means and the radiation source at a location near the radiation source and including movable means for blocking off-focus radiation emanating from points within said source other than said focal point, said movable means serving to delineate the beam perimeter to a second cross-sectional size and configuration which proportionally; corresponds to' said first crosssectional size and configuration;
  • said movable means including a plurality of movably mounted stems each rigidly supporting aplurality of vanes for movement as a unit toward and away from the beam path with the vanes supported by adjacent stems being interleaved;
  • connection means operably interconnecting said diaphragm means and said movable means for concurrently moving saiddiaphragm. means and said movable means toward and away from said beam axis whereby the beam perimeter delineated by said diaphragm means and said movable means proportionally decreases or increases in size
  • the first and second cross-sectional configurations continue to-proportionally correspond.
  • vanes are supported centrally on their respective stems and said stems extend generally axially along the beam bath and are movable to position said vanes transve rsely of the beam path.
  • a radiation collimator a radiation beam emanating from a radiation source and along abeam path comprising:
  • a. diaphragm means positioned along the beam path for delineating the perimeter of the beam
  • off-focus radiation collimation means positioned between said diaphragm means and the radiation source at a location near the radiation source comprising:
  • diaphragm structures i. opposed pairs of diaphragm structures, the diaphragm structures of each. pair being intercon-' 1 nected for concurrent movement toward and away from the beam path;
  • each of said diaphragm structures including an array of vanes movable together as a unit toward and away from the beam path; iii. the vanes of one pair of diaphragm structures being interleaved with the vanes of adjacent diaphragm structures; and, (1. connection means interconnecting said diaphragm means and said opposed pairs of diaphragm structures for concurrent movement toward and away from the beam axis.
  • the radiation collimator of claim 13 comprising two pairs of opposed diaphragm structures, the vanes of one of said pairs of diaphragm structures being interleaved with the vanes of the other of said pairs of diaphragm structures.
  • the radiation collimator of claim 14 wherein the outer sides of said vanes arecurved to give the assem- 18.
  • vanes nearest the X-ray source are configured such that their inner beam delineating edges remain at a substantially constant distance from the X-ray source as said nearest vanes are pivoted inwardly and outwardly toward and away from the beam path.
  • an X-ray apparatus having a source of X- radiation positioned to direct a beam of X-rays emanating from a focal point along a path toward a subject, the improvement of a collimator disposed along the beam path for collimating the beam comprising:
  • on-focus collimation means movable positioned within said housing structure at a position spaced from the source of X-radiation for adjustably delineating the perimeter of the X-ray beam at spaced locations along the beam path;
  • off-focus collimation means movably carried by said housing structure at a position between said on-focus collimation means and the source of X- radiation and operably coupled to said on-focus collimation means for movement therewith;
  • said off-focus collimation means comprising:
  • connection means interconnecting the diaphragm structures of each pair for concurrent movement toward and away from the beam path;
  • each of said diaphragm structures carrying a plurality of diaphragm plate means movable together as a unit toward and away from the beam path;
  • the plate means of one pair of diaphragm structures being interleaved with the plate means of the other pair of diaphragm structures at axially spaced positions along the beam path whereby either pair of diaphragm structures can be moved toward or away from the beam path independently of and without interfering with the operation of the other pair of diaphragm structures.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Apparatus For Radiation Diagnosis (AREA)
  • X-Ray Techniques (AREA)
US00327644A 1973-01-29 1973-01-29 Radiation collimator Expired - Lifetime US3829701A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US00327644A US3829701A (en) 1973-01-29 1973-01-29 Radiation collimator
CA191,252A CA991760A (en) 1973-01-29 1974-01-28 Radiation collimator
NL7401105A NL7401105A (enrdf_load_stackoverflow) 1973-01-29 1974-01-28
JP49011728A JPS49107485A (enrdf_load_stackoverflow) 1973-01-29 1974-01-28
FR7402925A FR2215777A1 (enrdf_load_stackoverflow) 1973-01-29 1974-01-29
DE2404194A DE2404194A1 (de) 1973-01-29 1974-01-29 Strahlungskollimator

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US00327644A US3829701A (en) 1973-01-29 1973-01-29 Radiation collimator

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JP (1) JPS49107485A (enrdf_load_stackoverflow)
CA (1) CA991760A (enrdf_load_stackoverflow)
DE (1) DE2404194A1 (enrdf_load_stackoverflow)
FR (1) FR2215777A1 (enrdf_load_stackoverflow)
NL (1) NL7401105A (enrdf_load_stackoverflow)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3936647A (en) * 1973-05-04 1976-02-03 Cgr Medical Corporation X-ray collimator for controlling the emission of secondary radiation
US3947690A (en) * 1974-07-11 1976-03-30 The Machlett Laboratories, Inc. Radiation limiting means
US4219734A (en) * 1977-07-29 1980-08-26 Compagnie Generale De Radiologie X-ray apparatus for transverse axial tomography
US4246488A (en) * 1979-03-09 1981-01-20 Picker Corporation Radiation collimator
US4380820A (en) * 1980-06-19 1983-04-19 The Machlett Laboratories, Incorporated Compact X-ray collimator
US4672648A (en) * 1985-10-25 1987-06-09 Picker International, Inc. Apparatus and method for radiation attenuation
US4692937A (en) * 1984-05-02 1987-09-08 University Of Pittsburgh Radiography apparatus and method
US4696022A (en) * 1984-01-27 1987-09-22 University Of Pittsburgh Stereoscopic radiography apparatus and method
EP0083756B1 (en) * 1981-12-23 1988-12-07 General Electric Company Collimator with adjustable aperture
EP0304773A1 (de) * 1987-08-26 1989-03-01 Siemens Aktiengesellschaft Primärstrahlenblende für Röntgendiagnostikgeräte
GB2211710A (en) * 1987-10-28 1989-07-05 Philips Nv Multileaf collimator
US4905268A (en) * 1985-10-25 1990-02-27 Picker International, Inc. Adjustable off-focal aperture for x-ray tubes
US4946238A (en) * 1984-01-27 1990-08-07 University Of Pittsburgh Fiber optic coupler
US5396534A (en) * 1993-10-12 1995-03-07 Thomas; Howard C. Shutter apparatus for collimating x-rays
US20060126792A1 (en) * 2004-12-09 2006-06-15 Ge Medical Systems Global Technology Company, Llc X-ray irradiator and X-ray imaging apparatus
US20060133575A1 (en) * 2004-12-21 2006-06-22 Advanced X-Ray Technology, Inc. X-ray needle apparatus and method for radiation treatment
US20100111261A1 (en) * 2007-03-13 2010-05-06 Koninklijke Philips Electronics N.V. Add-on-x-ray-collimator for non-symmetrical beam collimation
CN1786818B (zh) * 2004-12-09 2011-06-08 Ge医疗系统环球技术有限公司 X射线辐照器和x射线成像设备
US20170186507A1 (en) * 2015-12-28 2017-06-29 Tsinghua University Collimator and inspection system having the same
US20170256329A1 (en) * 2016-03-01 2017-09-07 Claymount Assemblies B.V. Collimator shutter drive mechanism

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2473776B1 (fr) * 1980-01-11 1985-07-05 Cgr Mev Appareil d'irradiation utilisant des sources radioactives
DE3604935A1 (de) * 1986-02-17 1987-08-20 Siemens Ag Blende mit kontinuierlich veraenderbarer wirksamer blendenoeffnung fuer diffraktometrische messeinrichtungen

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3936647A (en) * 1973-05-04 1976-02-03 Cgr Medical Corporation X-ray collimator for controlling the emission of secondary radiation
US3947690A (en) * 1974-07-11 1976-03-30 The Machlett Laboratories, Inc. Radiation limiting means
US4219734A (en) * 1977-07-29 1980-08-26 Compagnie Generale De Radiologie X-ray apparatus for transverse axial tomography
US4246488A (en) * 1979-03-09 1981-01-20 Picker Corporation Radiation collimator
US4380820A (en) * 1980-06-19 1983-04-19 The Machlett Laboratories, Incorporated Compact X-ray collimator
EP0083756B1 (en) * 1981-12-23 1988-12-07 General Electric Company Collimator with adjustable aperture
US4946238A (en) * 1984-01-27 1990-08-07 University Of Pittsburgh Fiber optic coupler
US4696022A (en) * 1984-01-27 1987-09-22 University Of Pittsburgh Stereoscopic radiography apparatus and method
US4692937A (en) * 1984-05-02 1987-09-08 University Of Pittsburgh Radiography apparatus and method
US4905268A (en) * 1985-10-25 1990-02-27 Picker International, Inc. Adjustable off-focal aperture for x-ray tubes
US4672648A (en) * 1985-10-25 1987-06-09 Picker International, Inc. Apparatus and method for radiation attenuation
US4897861A (en) * 1987-08-26 1990-01-30 Siemens Aktiengesellschaft Primary radiation diaphragm for x-ray diagnostics equipments
EP0304773A1 (de) * 1987-08-26 1989-03-01 Siemens Aktiengesellschaft Primärstrahlenblende für Röntgendiagnostikgeräte
GB2211710A (en) * 1987-10-28 1989-07-05 Philips Nv Multileaf collimator
US5396534A (en) * 1993-10-12 1995-03-07 Thomas; Howard C. Shutter apparatus for collimating x-rays
CN100561332C (zh) * 2004-12-09 2009-11-18 Ge医疗系统环球技术有限公司 X射线辐照器和x射线成像设备
US7092489B2 (en) * 2004-12-09 2006-08-15 Ge Medical Systems Global Technology Company, Llc X-ray irradiator and X-ray imaging apparatus
US20060126792A1 (en) * 2004-12-09 2006-06-15 Ge Medical Systems Global Technology Company, Llc X-ray irradiator and X-ray imaging apparatus
CN1786818B (zh) * 2004-12-09 2011-06-08 Ge医疗系统环球技术有限公司 X射线辐照器和x射线成像设备
US20060133575A1 (en) * 2004-12-21 2006-06-22 Advanced X-Ray Technology, Inc. X-ray needle apparatus and method for radiation treatment
US20100111261A1 (en) * 2007-03-13 2010-05-06 Koninklijke Philips Electronics N.V. Add-on-x-ray-collimator for non-symmetrical beam collimation
US8139719B2 (en) 2007-03-13 2012-03-20 Koninklijke Philips Electronics Nv Add-on-X-ray-collimator for non-symmetrical beam collimation
US20170186507A1 (en) * 2015-12-28 2017-06-29 Tsinghua University Collimator and inspection system having the same
US10658088B2 (en) * 2015-12-28 2020-05-19 Tsinghua University Collimator and inspection system having the same
US20170256329A1 (en) * 2016-03-01 2017-09-07 Claymount Assemblies B.V. Collimator shutter drive mechanism
US9892810B2 (en) * 2016-03-01 2018-02-13 Claymount Assemblies B.V. Collimator shutter drive mechanism

Also Published As

Publication number Publication date
FR2215777A1 (enrdf_load_stackoverflow) 1974-08-23
JPS49107485A (enrdf_load_stackoverflow) 1974-10-12
DE2404194A1 (de) 1974-08-01
NL7401105A (enrdf_load_stackoverflow) 1974-07-31
CA991760A (en) 1976-06-22

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