USRE32961E - Device for measuring local radiation absorption in a body - Google Patents

Device for measuring local radiation absorption in a body Download PDF

Info

Publication number
USRE32961E
USRE32961E US05/875,432 US87543278A USRE32961E US RE32961 E USRE32961 E US RE32961E US 87543278 A US87543278 A US 87543278A US RE32961 E USRE32961 E US RE32961E
Authority
US
United States
Prior art keywords
radiation
detectors
detector
circle
radiators
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US05/875,432
Inventor
Wolfgang Wagner
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
US Philips Corp
Original Assignee
US Philips Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE2442809A external-priority patent/DE2442809A1/en
Application filed by US Philips Corp filed Critical US Philips Corp
Priority to US05/875,432 priority Critical patent/USRE32961E/en
Application granted granted Critical
Publication of USRE32961E publication Critical patent/USRE32961E/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
    • A61B6/42—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment with arrangements for detecting radiation specially adapted for radiation diagnosis
    • A61B6/4275—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment with arrangements for detecting radiation specially adapted for radiation diagnosis using a detector unit almost surrounding the patient, e.g. more than 180°
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
    • A61B6/40—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment with arrangements for generating radiation specially adapted for radiation diagnosis
    • A61B6/4007—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment with arrangements for generating radiation specially adapted for radiation diagnosis characterised by using a plurality of source units
    • A61B6/4014—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment with arrangements for generating radiation specially adapted for radiation diagnosis characterised by using a plurality of source units arranged in multiple source-detector units

Definitions

  • the invention relates to a device for measuring the spatial distribution of radiation absorption in a body, wherein the radiation to be emitted by at least one radiator is measured in a large number of directions by means of a number of detectors which are successively arranged in one plane in the body, each detector having only a comparatively small effective measuring field, the spatial distribution being calculated from these measuring values.
  • a device of this kind is known, for example from German Offenlegungsschrift 1,941,433.
  • the radiator/detector system is displaced perpendicular to the radiation direction, and the absorption is measured in a large number of directly adjacent points. Subsequently, the radiator/detector system is rotated through a given angle, after which the operation is repeated, etc.
  • the time required for obtaining the necessary measuring values in this apparatus amounts to a few minutes, so that using this apparatus only bodies or body parts can be examined which can be kept completely immobile, as otherwise disturbances occur due to lack of focus.
  • the invention has for its object to provide a device for measuring the spatial distribution of the absorption of radiation in a body whereby the measuring time is reduced and in which the power of the radiator is more efficiently used.
  • a device of the kind set forth according to the invention is characterized in that the detectors are arranged in a row such that their effective measuring fields directly adjoin each other and cover the entire, approximately wedge-shaped stopped radiation of the radiator.
  • FIG. 1 is a diagrammatic view of a device according to the invention.
  • FIG. 2 shows such a device comprising various radiators arranged in a circle.
  • FIG. 1 shows a radiator 1 which can contain an X-ray tube or radio-active isotope.
  • a collimator 2 passes a wedge-like beam 7 of emitted radiation, the outer limits of said beam being denoted by 3 and 3'.
  • the beam 7 irradiates a body 4 to be examined.
  • Behind the body 4 a large number of detectors 5 are arranged in a circle around the radiator 1 such that their effective measuring fields adjoin each other in a contacting manner, with the result that the overall radiation wedge 3,3' is measured by the individual detectors.
  • the absorption in the directions determined by the connecting lines between the radiator and the detectors 5 can all be measured in one operation.
  • the radiator/detector system is preferably continuously rotated about the body 4, the radiation source being switched on and the absorption being measured in given angular positions. Because the absorption in the plane of examination can be determined by way of a single measurement in one position of the radiator/detector system, a substantial reduction of the examination time (to a few seconds) is feasible.
  • a scattered radiation diaphragm 6 which is arranged in front of the detectors 5 and a collimator (not shown in the drawing) which limits the beam in the direction perpendicular to the plane of the drawing such that only the detectors are struck by the radiation, ensure that the scattered radiation density in the region of the detectors remains substantially smaller than in the case of conventional tomography.
  • the scattered radiation density can be further reduced by arranging the detectors not directly behind the body, but rather at a larger distance therefrom, so that the opening angle as regards the scattered radiation centres in the body is reduced. In that case the geometrical lack of focus is increased, but this effect can be neglected, because in the device according to the invention--like in the known devices--substantially reduced spatial resolution is used.
  • the scattered radiation can be reduced by means of an additional diaphragm device to be provided between the collimator 2 and the radiator 1, if the said diaphragm opening is proportioned such that each time only a beam corresponding to the effective measuring field of one or only a few detectors is stopped, the diaphragm device being rotatable about the radiator such that during one rotation all detectors 5 are successively irradiated.
  • the required time is thus increased, but the measuring time can still be reduced, because in such a device the moving mass is essentially smaller that in the known devices.
  • the detectors 5 may comprise radiation-sensitive PbO-crystallites or HgI 2 -crystals, or use can alternatively be made of radiation-sensitive semiconductor detectors.
  • the use of light-sensitive photo-cells or photodetectors (photo-diodes, photo-field effecttransistors, etc.) is possible, these devices being preceded by an amplifier foil for converting X-radiation into visible light.
  • the detectors can be operated such that they supply a signal which is proportional to the dose power (in this case pre-amplifiers which form the time integral of the output signal of the detectors must be connected behind the detectors) or they may be connected such that their output signal is proportional to the dose, so that the subsequent pre-amplifiers only have to amplify the signal.
  • the subsequent computer (not elaborated herein) for measuring the spatial distribution of the absorption in the plane usually cannot process the measuring values in parallel; the detector output signals must therefor be applied to a storage element, for example, to a sample-and-hold amplifier, the outputs of all sample-and-hold amplifiers being connected to the computer via a multiplex device which successively applies the stored measuring values to the computer.
  • a further row of detectors may be provided in a direction perpendicular to the plane of the drawing, immediately adjoining the row of detectors shown. In that case, the radiation of the radiator must obviously be limited such that the two detector rows are struck by the radiation.
  • the absorption distribution in the two planes determined by the detector rows can be measured or, after addition of the measuring values each time supplied by two adjacent detectors, the mean absorption distribution for the two planes can be calculated, the signal-to-noise ratio thus being improved.
  • the gain of the pre-amplifiers connected behind the detectors is adjusted such that, in the case of direct radiation by the radiator (i.e. without the body 4 being in the beam path) the output signals are preferably the same.
  • an additional detector can be provided which is arranged above or below the plane of the drawing, so that the radiation measured thereby on the one hand is not attenuated by the body 4, to be examined, and the detector on the other hand does not influence the radiation measured by the other detectors.
  • the collimator arranged in front of the radiator must be provided with an additional opening in the correct position.
  • the absolute values of the measuring values being dependent of temporary fluctuations in the intensity of the radiator, should then no longer be used for the calculation, but rather the ratio between the measuring values of the row of detectors 5 on the one side and that of the additional detector on the other side, this ratio being independent of such fluctuations.
  • the row of detectors is directed exactly to the radiation beam formed by the collimators in front of the radiator.
  • Alignment can be effected by means of an optical adjusting device (not shown) which is permanently connected to the radiator 1 and which emits light rays by means of a mirror device, the position and the direction of the two outer light rays corresponding to the position and the direction of the boundary lines 3,3', whilst the third light ray coincides with the bisector between these two rays.
  • the row of detectors 5 can thus be more readily directed to the radiator.
  • the light rays produce light spots on the object to be examined, the layer to be measured thus being optically marked.
  • FIG. 2 shows an embodiment of the device according to the invention which enables a further reduction of the measuring time.
  • a number of radiators (11 in the drawing) 11-21 are arranged in a circle, in the centre of which the object 4 is to be arranged, each time a row of detectors 51-61 being associated with the said radiators, diametrically opposite in the space between two adjacent radiators.
  • the absorption in the plane of the body can be simultaneously or almost simultaneously measured in a number of directions corresponding to the number of radiators.
  • the scattered radiation density would be substantially increased in comparison with the device shown in FIG. 1. So as to avoid this phenomenon, the X-radiators and the associated rows of detectors can be successively switched on. This can be effected within fractions of seconds.
  • the number of radiator/detector systems cannot be made as high as the number of directions in which the absorption is to be measured in the separate regions of the plane of the body to be examined.
  • These measurements can be performed in a comparatively short time, because the device need be rotated only through a small angle and because the rotary movement can be continuously performed. Therefore, planes of bodies which can only be very briefly immobilized can also be examined.

Abstract

A device for measuring the spatial distribution of radiation absorption in a body wherein a multiplicity of radiators are regularly distributed about a circle surrounding the body, each radiator emitting a wedge-shaped beam of radiation in the plane of the circle toward a different arc portion of the circle beween two other radiators, a multiplicity of adjoining detectors in each arc portion measuring radiation from the radiator emitting radiation to that arc portion, the spatial distribution of radiation absorption being calculated from the measured radiation values of all the detectors.

Description

The invention relates to a device for measuring the spatial distribution of radiation absorption in a body, wherein the radiation to be emitted by at least one radiator is measured in a large number of directions by means of a number of detectors which are successively arranged in one plane in the body, each detector having only a comparatively small effective measuring field, the spatial distribution being calculated from these measuring values.
A device of this kind is known, for example from German Offenlegungsschrift 1,941,433. Therein, the radiator/detector system is displaced perpendicular to the radiation direction, and the absorption is measured in a large number of directly adjacent points. Subsequently, the radiator/detector system is rotated through a given angle, after which the operation is repeated, etc. The time required for obtaining the necessary measuring values in this apparatus amounts to a few minutes, so that using this apparatus only bodies or body parts can be examined which can be kept completely immobile, as otherwise disturbances occur due to lack of focus.
It is already known to reduce this measuring time (German Offenlegungsschrift 1,941,433, FIG. 7) by measuring the radiation emitted by the radiator by means of a plurality of detectors which are arranged in a arc of a circle around the radiator, each detector measuring the radiation stopped by a collimator associated with the detector. In order to measure the absorption in the parts which are not irradiated during a first measuring series, the detectors and the associated collimators are translated until all regions of the body to be examined and which have not yet been irradiated have been covered. Subsequently, the radiator and the associated collimators and detectors are rotated through a given angle, and simultaneously the detectors are translated back, after which the operation is repeated. The complete measurement, however, is still comparatively time-consuming in this apparatus. Moreover, always only a very small part of the radiation emitted by the radiator is used for the measurement (i.e. the radiation which is stopped by the collimators), so that when use is made of an X-ray tube as the radiator, this X-ray tube must be operated to the limit of loadability. This has an adverse effect on the service life of the X-ray tube and on the reliability of the apparatus.
The invention has for its object to provide a device for measuring the spatial distribution of the absorption of radiation in a body whereby the measuring time is reduced and in which the power of the radiator is more efficiently used.
To this end, a device of the kind set forth according to the invention is characterized in that the detectors are arranged in a row such that their effective measuring fields directly adjoin each other and cover the entire, approximately wedge-shaped stopped radiation of the radiator.
The invention will be described in detail hereinafter with reference to the drawing.
FIG. 1 is a diagrammatic view of a device according to the invention.
FIG. 2 shows such a device comprising various radiators arranged in a circle.
FIG. 1 shows a radiator 1 which can contain an X-ray tube or radio-active isotope. A collimator 2 passes a wedge-like beam 7 of emitted radiation, the outer limits of said beam being denoted by 3 and 3'. The beam 7 irradiates a body 4 to be examined. Behind the body 4, a large number of detectors 5 are arranged in a circle around the radiator 1 such that their effective measuring fields adjoin each other in a contacting manner, with the result that the overall radiation wedge 3,3' is measured by the individual detectors. Using this device, the absorption in the directions determined by the connecting lines between the radiator and the detectors 5 can all be measured in one operation. So as to obtain the absorption distribution in the other directions, the radiator/detector system is preferably continuously rotated about the body 4, the radiation source being switched on and the absorption being measured in given angular positions. Because the absorption in the plane of examination can be determined by way of a single measurement in one position of the radiator/detector system, a substantial reduction of the examination time (to a few seconds) is feasible.
A scattered radiation diaphragm 6 which is arranged in front of the detectors 5 and a collimator (not shown in the drawing) which limits the beam in the direction perpendicular to the plane of the drawing such that only the detectors are struck by the radiation, ensure that the scattered radiation density in the region of the detectors remains substantially smaller than in the case of conventional tomography. The scattered radiation density can be further reduced by arranging the detectors not directly behind the body, but rather at a larger distance therefrom, so that the opening angle as regards the scattered radiation centres in the body is reduced. In that case the geometrical lack of focus is increased, but this effect can be neglected, because in the device according to the invention--like in the known devices--substantially reduced spatial resolution is used. In particularly critical cases, the scattered radiation can be reduced by means of an additional diaphragm device to be provided between the collimator 2 and the radiator 1, if the said diaphragm opening is proportioned such that each time only a beam corresponding to the effective measuring field of one or only a few detectors is stopped, the diaphragm device being rotatable about the radiator such that during one rotation all detectors 5 are successively irradiated. The required time is thus increased, but the measuring time can still be reduced, because in such a device the moving mass is essentially smaller that in the known devices.
The detectors 5 may comprise radiation-sensitive PbO-crystallites or HgI2 -crystals, or use can alternatively be made of radiation-sensitive semiconductor detectors. For example, the use of light-sensitive photo-cells or photodetectors (photo-diodes, photo-field effecttransistors, etc.) is possible, these devices being preceded by an amplifier foil for converting X-radiation into visible light. The detectors can be operated such that they supply a signal which is proportional to the dose power (in this case pre-amplifiers which form the time integral of the output signal of the detectors must be connected behind the detectors) or they may be connected such that their output signal is proportional to the dose, so that the subsequent pre-amplifiers only have to amplify the signal. Because the measuring values of all detectors are each time simultaneously released for one direction, the subsequent computer (not elaborated herein) for measuring the spatial distribution of the absorption in the plane usually cannot process the measuring values in parallel; the detector output signals must therefor be applied to a storage element, for example, to a sample-and-hold amplifier, the outputs of all sample-and-hold amplifiers being connected to the computer via a multiplex device which successively applies the stored measuring values to the computer.
In addition to the row of detectors shown in FIG. 1, a further row of detectors may be provided in a direction perpendicular to the plane of the drawing, immediately adjoining the row of detectors shown. In that case, the radiation of the radiator must obviously be limited such that the two detector rows are struck by the radiation. During the subsequent processing of the measuring values supplied by the two rows of detectors, either the absorption distribution in the two planes determined by the detector rows can be measured or, after addition of the measuring values each time supplied by two adjacent detectors, the mean absorption distribution for the two planes can be calculated, the signal-to-noise ratio thus being improved.
In practice the fact must be taken into account that the intensity of the radiation emitted by the radiator is not uniformly distributed over the radiation wedge 3 and that the sensitivity of the individual cells may differ. To this end, the gain of the pre-amplifiers connected behind the detectors is adjusted such that, in the case of direct radiation by the radiator (i.e. without the body 4 being in the beam path) the output signals are preferably the same.
In order to prevent the distribution of the absorption in the plane of the body to be calculated from the measuring values from being influenced by temporary fluctuations in the radiation intensity, an additional detector can be provided which is arranged above or below the plane of the drawing, so that the radiation measured thereby on the one hand is not attenuated by the body 4, to be examined, and the detector on the other hand does not influence the radiation measured by the other detectors. To this end, the collimator arranged in front of the radiator must be provided with an additional opening in the correct position. The absolute values of the measuring values, being dependent of temporary fluctuations in the intensity of the radiator, should then no longer be used for the calculation, but rather the ratio between the measuring values of the row of detectors 5 on the one side and that of the additional detector on the other side, this ratio being independent of such fluctuations.
For the operation of the device it is important that the row of detectors is directed exactly to the radiation beam formed by the collimators in front of the radiator. Alignment can be effected by means of an optical adjusting device (not shown) which is permanently connected to the radiator 1 and which emits light rays by means of a mirror device, the position and the direction of the two outer light rays corresponding to the position and the direction of the boundary lines 3,3', whilst the third light ray coincides with the bisector between these two rays. The row of detectors 5 can thus be more readily directed to the radiator. Moreover, the light rays produce light spots on the object to be examined, the layer to be measured thus being optically marked.
FIG. 2 shows an embodiment of the device according to the invention which enables a further reduction of the measuring time. Therein, a number of radiators (11 in the drawing) 11-21 are arranged in a circle, in the centre of which the object 4 is to be arranged, each time a row of detectors 51-61 being associated with the said radiators, diametrically opposite in the space between two adjacent radiators. Using this device, the absorption in the plane of the body can be simultaneously or almost simultaneously measured in a number of directions corresponding to the number of radiators.
If all radiators were simultaneously switched on, the scattered radiation density would be substantially increased in comparison with the device shown in FIG. 1. So as to avoid this phenomenon, the X-radiators and the associated rows of detectors can be successively switched on. This can be effected within fractions of seconds.
On the basis of spatial and economic considerations, in practice the number of radiator/detector systems cannot be made as high as the number of directions in which the absorption is to be measured in the separate regions of the plane of the body to be examined. In order to measure the absorption in all necessary directions, therefore, the system consisting of the radiators and the associated rows of detectors is rotated about the body to be examined (or the body relative to the system), during one rotation through the angle 2π/n (n=number of radiators) all radiators being actuated m times, so that the absorption can be measured in m×n different directions. These measurements can be performed in a comparatively short time, because the device need be rotated only through a small angle and because the rotary movement can be continuously performed. Therefore, planes of bodies which can only be very briefly immobilized can also be examined.

Claims (4)

What is claimed is:
1. A device for measuring the spatial distribution of radiation absorption in a body, comprising:
a multiplicity of radiators regularly distributed about a circle of diameter sufficient to surround said body, each radiator emitting a wedge-shaped beam of radiation in the plane of said circle toward a different arc portion of said circle between two other radiators; and
a multiplicity of adjoining detectors in each of said different arc portions of said circle to measure radiation from the associated radiator emitting radiation thereto, each detector having only a comparatively small effective measuring field, the spatial distribution being calculated from the measured radiation values from said detectors.
2. The device defined in claim 1 wherein said circle of radiators and detectors is rotatable in the plane thereof with respect to said body to measure radiation values in different rotary orientations thereof.
3. The device defined in claim 2 wherein said radiators and detectors may be successively rendered effective. .Iadd.
4. An apparatus for examining a body by means of penetrating radiation including a source means arranged to irradate the body with a planar spread of said radiation, detector means arranged to detect the radiation to provide output signals, relating to absorption of the radiation by the body, for processing to provide a representation of the distribution of absorption in a substantially planar section of the body and means adapted to scan the planar spread of radiation in relation to the body so as to irradate said section along a plurality of beam paths passing through the body from a plurality of direction, wherein said detector means comprises a plurality of detector devices of which a predetermined number are irradiated by said spread at any time and wherein the scanning means is arranged to traverse the spread of X-rays along the detector device so as to change the irradiated device progressively. .Iaddend. .Iadd.5. An apparatus according to claim 4 wherein the scanning means include means adapted to move said source means in relation to the body to provide at least part of the scanning of said spread of radiation. .Iaddend. .Iadd.6. An apparatus according to claim 4 including means adapted to move said detector means relative to the body. .Iaddend. .Iadd.7. An apparatus according to claim 4 in which the scanning means include means adapted to provide at least a rotational motion of said spread of radiation relative to the body. .Iaddend. .Iadd.8. An apparatus according to claim 4 including collimator means adapted to restrict the number of said detector devices irradiated at any time. .Iaddend. .Iadd.9. An apparatus according to claim 8 including means for moving the collimator means in relation to the detector means to change the detector devices so irradiated. .Iaddend.
US05/875,432 1974-09-06 1978-02-06 Device for measuring local radiation absorption in a body Expired - Lifetime USRE32961E (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US05/875,432 USRE32961E (en) 1974-09-06 1978-02-06 Device for measuring local radiation absorption in a body

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE2442809 1974-09-06
DE2442809A DE2442809A1 (en) 1974-09-06 1974-09-06 ARRANGEMENT FOR DETERMINING ABSORPTION IN A BODY
US05/875,432 USRE32961E (en) 1974-09-06 1978-02-06 Device for measuring local radiation absorption in a body

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US05/610,616 Reissue US4057725A (en) 1974-09-06 1975-09-05 Device for measuring local radiation absorption in a body

Publications (1)

Publication Number Publication Date
USRE32961E true USRE32961E (en) 1989-06-20

Family

ID=25767658

Family Applications (1)

Application Number Title Priority Date Filing Date
US05/875,432 Expired - Lifetime USRE32961E (en) 1974-09-06 1978-02-06 Device for measuring local radiation absorption in a body

Country Status (1)

Country Link
US (1) USRE32961E (en)

Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040101087A1 (en) * 2002-11-27 2004-05-27 Jiang Hsieh Methods and apparatus for generating CT scout images
US20060018423A1 (en) * 2004-06-24 2006-01-26 Herbert Bruder Imaging tomography apparatus with two acquisition systems, and method for determining their system angles
US7349525B2 (en) 2003-04-25 2008-03-25 Rapiscan Systems, Inc. X-ray sources
US20080144774A1 (en) * 2003-04-25 2008-06-19 Crx Limited X-Ray Tubes
US7512215B2 (en) 2003-04-25 2009-03-31 Rapiscan Systems, Inc. X-ray tube electron sources
US7564939B2 (en) 2003-04-25 2009-07-21 Rapiscan Systems, Inc. Control means for heat load in X-ray scanning apparatus
US7684538B2 (en) 2003-04-25 2010-03-23 Rapiscan Systems, Inc. X-ray scanning system
US7949101B2 (en) 2005-12-16 2011-05-24 Rapiscan Systems, Inc. X-ray scanners and X-ray sources therefor
US8094784B2 (en) 2003-04-25 2012-01-10 Rapiscan Systems, Inc. X-ray sources
US8135110B2 (en) 2005-12-16 2012-03-13 Rapiscan Systems, Inc. X-ray tomography inspection systems
US8451974B2 (en) 2003-04-25 2013-05-28 Rapiscan Systems, Inc. X-ray tomographic inspection system for the identification of specific target items
US8824637B2 (en) 2008-09-13 2014-09-02 Rapiscan Systems, Inc. X-ray tubes
US8837669B2 (en) 2003-04-25 2014-09-16 Rapiscan Systems, Inc. X-ray scanning system
US9020095B2 (en) 2003-04-25 2015-04-28 Rapiscan Systems, Inc. X-ray scanners
US9052403B2 (en) 2002-07-23 2015-06-09 Rapiscan Systems, Inc. Compact mobile cargo scanning system
US9113839B2 (en) 2003-04-25 2015-08-25 Rapiscon Systems, Inc. X-ray inspection system and method
US9208988B2 (en) 2005-10-25 2015-12-08 Rapiscan Systems, Inc. Graphite backscattered electron shield for use in an X-ray tube
US9218933B2 (en) 2011-06-09 2015-12-22 Rapidscan Systems, Inc. Low-dose radiographic imaging system
US9223049B2 (en) 2002-07-23 2015-12-29 Rapiscan Systems, Inc. Cargo scanning system with boom structure
US9223050B2 (en) 2005-04-15 2015-12-29 Rapiscan Systems, Inc. X-ray imaging system having improved mobility
US9223052B2 (en) 2008-02-28 2015-12-29 Rapiscan Systems, Inc. Scanning systems
US9263225B2 (en) 2008-07-15 2016-02-16 Rapiscan Systems, Inc. X-ray tube anode comprising a coolant tube
US9285498B2 (en) 2003-06-20 2016-03-15 Rapiscan Systems, Inc. Relocatable X-ray imaging system and method for inspecting commercial vehicles and cargo containers
US9332624B2 (en) 2008-05-20 2016-05-03 Rapiscan Systems, Inc. Gantry scanner systems
US9420677B2 (en) 2009-01-28 2016-08-16 Rapiscan Systems, Inc. X-ray tube electron sources
US9429530B2 (en) 2008-02-28 2016-08-30 Rapiscan Systems, Inc. Scanning systems
US9726619B2 (en) 2005-10-25 2017-08-08 Rapiscan Systems, Inc. Optimization of the source firing pattern for X-ray scanning systems
US9791590B2 (en) 2013-01-31 2017-10-17 Rapiscan Systems, Inc. Portable security inspection system
US10483077B2 (en) 2003-04-25 2019-11-19 Rapiscan Systems, Inc. X-ray sources having reduced electron scattering
US10591424B2 (en) 2003-04-25 2020-03-17 Rapiscan Systems, Inc. X-ray tomographic inspection systems for the identification of specific target items
US11551903B2 (en) 2020-06-25 2023-01-10 American Science And Engineering, Inc. Devices and methods for dissipating heat from an anode of an x-ray tube assembly

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3866047A (en) * 1968-08-23 1975-02-11 Emi Ltd Penetrating radiation examining apparatus having a scanning collimator
US3881110A (en) * 1972-05-17 1975-04-29 Emi Ltd Penetrating radiation examining apparatus in combination with body locating structure

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3866047A (en) * 1968-08-23 1975-02-11 Emi Ltd Penetrating radiation examining apparatus having a scanning collimator
US3881110A (en) * 1972-05-17 1975-04-29 Emi Ltd Penetrating radiation examining apparatus in combination with body locating structure

Cited By (64)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10670769B2 (en) 2002-07-23 2020-06-02 Rapiscan Systems, Inc. Compact mobile cargo scanning system
US9223049B2 (en) 2002-07-23 2015-12-29 Rapiscan Systems, Inc. Cargo scanning system with boom structure
US10007019B2 (en) 2002-07-23 2018-06-26 Rapiscan Systems, Inc. Compact mobile cargo scanning system
US9052403B2 (en) 2002-07-23 2015-06-09 Rapiscan Systems, Inc. Compact mobile cargo scanning system
US7031425B2 (en) * 2002-11-27 2006-04-18 Ge Medical Systems Global Technology Company, Llc Methods and apparatus for generating CT scout images
US20040101087A1 (en) * 2002-11-27 2004-05-27 Jiang Hsieh Methods and apparatus for generating CT scout images
US8085897B2 (en) 2003-04-25 2011-12-27 Rapiscan Systems, Inc. X-ray scanning system
US10591424B2 (en) 2003-04-25 2020-03-17 Rapiscan Systems, Inc. X-ray tomographic inspection systems for the identification of specific target items
US7512215B2 (en) 2003-04-25 2009-03-31 Rapiscan Systems, Inc. X-ray tube electron sources
US7564939B2 (en) 2003-04-25 2009-07-21 Rapiscan Systems, Inc. Control means for heat load in X-ray scanning apparatus
US20090274277A1 (en) * 2003-04-25 2009-11-05 Edward James Morton X-Ray Sources
US20090316855A1 (en) * 2003-04-25 2009-12-24 Edward James Morton Control Means for Heat Load in X-Ray Scanning Apparatus
US7664230B2 (en) 2003-04-25 2010-02-16 Rapiscan Systems, Inc. X-ray tubes
US7684538B2 (en) 2003-04-25 2010-03-23 Rapiscan Systems, Inc. X-ray scanning system
US20100172476A1 (en) * 2003-04-25 2010-07-08 Edward James Morton X-Ray Tubes
US20100195788A1 (en) * 2003-04-25 2010-08-05 Edward James Morton X-Ray Scanning System
US7903789B2 (en) 2003-04-25 2011-03-08 Rapiscan Systems, Inc. X-ray tube electron sources
US11796711B2 (en) 2003-04-25 2023-10-24 Rapiscan Systems, Inc. Modular CT scanning system
US9442082B2 (en) 2003-04-25 2016-09-13 Rapiscan Systems, Inc. X-ray inspection system and method
US8094784B2 (en) 2003-04-25 2012-01-10 Rapiscan Systems, Inc. X-ray sources
US10901112B2 (en) 2003-04-25 2021-01-26 Rapiscan Systems, Inc. X-ray scanning system with stationary x-ray sources
US8451974B2 (en) 2003-04-25 2013-05-28 Rapiscan Systems, Inc. X-ray tomographic inspection system for the identification of specific target items
US20080267355A1 (en) * 2003-04-25 2008-10-30 Edward James Morton X-Ray Sources
US7505563B2 (en) 2003-04-25 2009-03-17 Rapiscan Systems, Inc. X-ray sources
US8837669B2 (en) 2003-04-25 2014-09-16 Rapiscan Systems, Inc. X-ray scanning system
US8885794B2 (en) 2003-04-25 2014-11-11 Rapiscan Systems, Inc. X-ray tomographic inspection system for the identification of specific target items
US10483077B2 (en) 2003-04-25 2019-11-19 Rapiscan Systems, Inc. X-ray sources having reduced electron scattering
US9001973B2 (en) 2003-04-25 2015-04-07 Rapiscan Systems, Inc. X-ray sources
US9020095B2 (en) 2003-04-25 2015-04-28 Rapiscan Systems, Inc. X-ray scanners
US10175381B2 (en) 2003-04-25 2019-01-08 Rapiscan Systems, Inc. X-ray scanners having source points with less than a predefined variation in brightness
US20080144774A1 (en) * 2003-04-25 2008-06-19 Crx Limited X-Ray Tubes
US9113839B2 (en) 2003-04-25 2015-08-25 Rapiscon Systems, Inc. X-ray inspection system and method
US7349525B2 (en) 2003-04-25 2008-03-25 Rapiscan Systems, Inc. X-ray sources
US9618648B2 (en) 2003-04-25 2017-04-11 Rapiscan Systems, Inc. X-ray scanners
US9675306B2 (en) 2003-04-25 2017-06-13 Rapiscan Systems, Inc. X-ray scanning system
US9285498B2 (en) 2003-06-20 2016-03-15 Rapiscan Systems, Inc. Relocatable X-ray imaging system and method for inspecting commercial vehicles and cargo containers
US20060018423A1 (en) * 2004-06-24 2006-01-26 Herbert Bruder Imaging tomography apparatus with two acquisition systems, and method for determining their system angles
US7263157B2 (en) * 2004-06-24 2007-08-28 Siemens Aktiengesellschaft Imaging tomography apparatus with two acquisition systems, and method for determining their system angles
US9223050B2 (en) 2005-04-15 2015-12-29 Rapiscan Systems, Inc. X-ray imaging system having improved mobility
US9208988B2 (en) 2005-10-25 2015-12-08 Rapiscan Systems, Inc. Graphite backscattered electron shield for use in an X-ray tube
US9726619B2 (en) 2005-10-25 2017-08-08 Rapiscan Systems, Inc. Optimization of the source firing pattern for X-ray scanning systems
US10976271B2 (en) 2005-12-16 2021-04-13 Rapiscan Systems, Inc. Stationary tomographic X-ray imaging systems for automatically sorting objects based on generated tomographic images
US8135110B2 (en) 2005-12-16 2012-03-13 Rapiscan Systems, Inc. X-ray tomography inspection systems
US10295483B2 (en) 2005-12-16 2019-05-21 Rapiscan Systems, Inc. Data collection, processing and storage systems for X-ray tomographic images
US9638646B2 (en) 2005-12-16 2017-05-02 Rapiscan Systems, Inc. X-ray scanners and X-ray sources therefor
US8625735B2 (en) 2005-12-16 2014-01-07 Rapiscan Systems, Inc. X-ray scanners and X-ray sources therefor
US9048061B2 (en) 2005-12-16 2015-06-02 Rapiscan Systems, Inc. X-ray scanners and X-ray sources therefor
US7949101B2 (en) 2005-12-16 2011-05-24 Rapiscan Systems, Inc. X-ray scanners and X-ray sources therefor
US8958526B2 (en) 2005-12-16 2015-02-17 Rapiscan Systems, Inc. Data collection, processing and storage systems for X-ray tomographic images
US10585207B2 (en) 2008-02-28 2020-03-10 Rapiscan Systems, Inc. Scanning systems
US11275194B2 (en) 2008-02-28 2022-03-15 Rapiscan Systems, Inc. Scanning systems
US11768313B2 (en) 2008-02-28 2023-09-26 Rapiscan Systems, Inc. Multi-scanner networked systems for performing material discrimination processes on scanned objects
US9223052B2 (en) 2008-02-28 2015-12-29 Rapiscan Systems, Inc. Scanning systems
US9429530B2 (en) 2008-02-28 2016-08-30 Rapiscan Systems, Inc. Scanning systems
US10098214B2 (en) 2008-05-20 2018-10-09 Rapiscan Systems, Inc. Detector support structures for gantry scanner systems
US9332624B2 (en) 2008-05-20 2016-05-03 Rapiscan Systems, Inc. Gantry scanner systems
US9263225B2 (en) 2008-07-15 2016-02-16 Rapiscan Systems, Inc. X-ray tube anode comprising a coolant tube
US8824637B2 (en) 2008-09-13 2014-09-02 Rapiscan Systems, Inc. X-ray tubes
US9420677B2 (en) 2009-01-28 2016-08-16 Rapiscan Systems, Inc. X-ray tube electron sources
US9218933B2 (en) 2011-06-09 2015-12-22 Rapidscan Systems, Inc. Low-dose radiographic imaging system
US9791590B2 (en) 2013-01-31 2017-10-17 Rapiscan Systems, Inc. Portable security inspection system
US11550077B2 (en) 2013-01-31 2023-01-10 Rapiscan Systems, Inc. Portable vehicle inspection portal with accompanying workstation
US10317566B2 (en) 2013-01-31 2019-06-11 Rapiscan Systems, Inc. Portable security inspection system
US11551903B2 (en) 2020-06-25 2023-01-10 American Science And Engineering, Inc. Devices and methods for dissipating heat from an anode of an x-ray tube assembly

Similar Documents

Publication Publication Date Title
USRE32961E (en) Device for measuring local radiation absorption in a body
US4057725A (en) Device for measuring local radiation absorption in a body
US4384209A (en) Method of and device for determining the contour of a body by means of radiation scattered by the body
JPH0725923Y2 (en) Computer tomograph
US4298799A (en) Radiography
US6087665A (en) Multi-layered scintillators for computed tomograph systems
US5781606A (en) X-ray tomography system with substantially continuous radiation detection zone
US4286156A (en) Device for determining the spatial absorption distribution in a plane of examination
US6380540B1 (en) Radiation imaging using simultaneous emission and transmission
US4433427A (en) Method and apparatus for examining a body by means of penetrating radiation such as X-rays
US4692937A (en) Radiography apparatus and method
JPH0126019B2 (en)
JP5283382B2 (en) Nuclear medicine detector
US4138611A (en) Fan beam CT apparatus with post-processing weighting of picture element signals
US4437006A (en) Method and apparatus for measuring radiation in computer-assisted tomography and radiographic applications
JPS5892974A (en) Radiation type computer-aided tomograph
US4896342A (en) X-ray apparatus
US20050161609A1 (en) X-ray detector module for spectrally resolved measurements
US4069422A (en) Apparatus for examining objects by means of penetrating radiation
GB1571510A (en) Radiography
US6266434B1 (en) Methods and apparatus for reducing spectral artifacts in a computed tomograph system
KR101835530B1 (en) Method and device for determining the x-ray radiation attenuation caused by the object to be examined
US10989819B2 (en) Gamma radiation detector with parallax compensation
US6725084B2 (en) Apparatus for measuring nonuniform attenuation in a scintillation camera
JPS6199844A (en) Instrument for inspecting surface of cylindrical body