WO2007028692A1 - Correction de rayonnement diffuse dans une image radiographique par mesures multiples d'objets de reference - Google Patents

Correction de rayonnement diffuse dans une image radiographique par mesures multiples d'objets de reference Download PDF

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Publication number
WO2007028692A1
WO2007028692A1 PCT/EP2006/065341 EP2006065341W WO2007028692A1 WO 2007028692 A1 WO2007028692 A1 WO 2007028692A1 EP 2006065341 W EP2006065341 W EP 2006065341W WO 2007028692 A1 WO2007028692 A1 WO 2007028692A1
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WO
WIPO (PCT)
Prior art keywords
detector
scattered radiation
scanning region
outside
measurement
Prior art date
Application number
PCT/EP2006/065341
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German (de)
English (en)
Inventor
Karl Stierstorfer
Original Assignee
Siemens Aktiengesellschaft
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Filing date
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Publication of WO2007028692A1 publication Critical patent/WO2007028692A1/fr

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
    • G01N23/04—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and forming images of the material
    • G01N23/046—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and forming images of the material using tomography, e.g. computed tomography [CT]
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/58—Testing, adjusting or calibrating thereof
    • A61B6/582—Calibration
    • A61B6/583—Calibration using calibration phantoms
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2223/00—Investigating materials by wave or particle radiation
    • G01N2223/40—Imaging
    • G01N2223/419—Imaging computed tomograph

Definitions

  • the invention relates to a calibration method and a correction method for an X-ray device and to an X-ray device for carrying out such a calibration or correction method.
  • an X-ray device which has a measuring arrangement with an X-ray source and a detector for detecting projections of an object.
  • X-ray source and detector are arranged opposite one another such that an X-ray radiation generated by the X-ray source radiates through a scanning region in which the object is positioned and subsequently impinges on the detector.
  • the primary X-ray radiation emanating from the X-ray source is weakened as it passes through the object not only as a function of the local absorption properties of the object, but also scattered in different spatial directions onto adjacent detector elements due to interactions of the X-radiation with the matter.
  • the measurement signal of a respective detector element is thus composed of a portion which originates from the primary x-ray radiation and thus represents the weakening of the x-ray radiation by the object and a portion, which of the
  • the detector known from DE 26 42 846 A1 has two detector rows arranged next to one another, the first detector row being uncorrected Measured signals detected by a scanning of the primary X-ray scanning area and detects the second detector line, the pure scattered radiation outside the irradiated scanning area.
  • the two detector rows are arranged directly next to one another, so that the two detector rows detect approximately the same scattered radiation in the direction of the axis of rotation of the X-ray device. For this reason, the measuring signals of the detector elements within the scanning area can be corrected by the measured scattered radiation being adjacent to that in the direction of the system axis
  • Detector element is subtracted from the corresponding measurement signal.
  • a method for operating such an X-ray device in which the detector elements are subjected to a calibration procedure to compensate for differences in gain between the detector elements before the correction of the measurement signals.
  • the detector is adjustable in the direction of the axis of rotation so that the detector line within the scanning range for calibration can be adjusted to the position of that detector row which is normally outside the scanning range.
  • a measuring signal outside the scanning area is detected in this way for each detector element.
  • the correction factors for the correction of the gain differences are then calculated from the quotient of the two measurement signals of the detector elements, which are adjacent to one another in the direction of the axis of rotation.
  • the object of the present invention is that in an X-ray device, the prerequisites are created for largely avoiding image artifacts in images caused by scattered radiation.
  • the measuring arrangement having an X-ray source for generating X-ray radiation and a detector comprising a plurality of detector elements, are arranged such that a first part of the detector elements generate measurement signals of a scan area irradiated by the X-ray radiation and that a second part of the detector elements generate measurement signals of a pure scattered radiation outside the irradiated scan area, for each detector element k outside the scan area from the measurement signals S 3 .
  • k of the scattered radiation a correction factor qk is calculated, so that a corrected value of the scattered radiation of the detector element k can be calculated.
  • the determination of the correction factors q k for those detector elements which are provided for detecting the scattered radiation is therefore carried out not only on the basis of a single measurement signal of a measurement, but on the basis of a plurality of measurement signals S 3. , K from different measurements i, so that a much higher accuracy of the correction factors q k is achieved. An interference signal caused by measurement noise in the calculation of the correction factors q k is thus largely avoidable.
  • the scattered radiation actually acting on the detector element can then be calculated.
  • the measurements i are advantageously carried out not only from one projection direction, but from a plurality of different projection directions.
  • this has the advantage that the scattered radiation acting on the detector elements varies depending on the direction of projection, so that different signal amplitudes or magnitudes of the measuring signals Si, k are generated.
  • correction factors q k are advantageously determinable which take into account a nonlinear relationship between the measurement signals Si, k and the intensity of the scattered radiation. In this case, it would thus be possible to determine the correction factor q k as a function of the magnitude of the measurement signal.
  • the reference bodies can be, for example, water phantoms with a cylindrical shape, which have different diameters.
  • the correction factor qk of the respective detector element is preferably calculated from the following weighted sum:
  • k denotes the k-th detector element outside the scanning range, i the i-th measurement, X 1 a weighting factor, S the measuring signal and R the reference signal of the detector element k and the sum of the weighting factors ⁇ i all measurements i equals one.
  • M 512 detector elements which are used to detect the scattering.
  • Equation 1 the following equation can also be advantageously used to calculate the correction factors q k :
  • This type of calculation has the advantage that even with a very small measurement signal, the result of the division can be determined unambiguously and the correction factor q k can be calculated in a secure manner.
  • the same weighting factor ⁇ i is used for each measurement, so that the correction factor corresponds to the mean value of all measurements.
  • the weighting factors ⁇ i such that the weighting factor ⁇ i is greater for large measuring signals than for small measuring signals. In this case, the fact is taken into account that large amounts of the measurement signals generally have a better signal-to-noise ratio.
  • the reference signals Ri, k are determined in advance for each measurement i by means of a calibrated detector.
  • the reference signals Ri, k correspond to the true intensities of the scattered radiation observed for a reference body and only need to be determined once.
  • the reference signals Ri, k can be determined, for example, with a specially provided laboratory device and are then used in the course of a device set-up for calibrating other X-ray devices with a measuring device that is the same as the laboratory device. It is also conceivable that the reference signals R 1 , k are advantageously determined for each measurement i by means of a simulation in advance of the calibration procedure.
  • the x-ray radiation generated by the x-ray source, the scattering properties of the reference body and the conversion of the scattered radiation incident on a detector element into measuring signals are simulated by means of a mathematical model.
  • the simulation makes it possible, in particular with little effort, to quickly determine reference signals for reference bodies that are different in shape and / or material.
  • the object is likewise achieved by means of a correction method for an X-ray device for correcting scattered radiation with a measuring arrangement comprising an X-ray source for generating X-ray radiation and a detector comprising a plurality of detector elements arranged such that a first part of the detector elements comprises measurement signals of the generate scanning regions irradiated by the X-ray radiation and that a second part of the detector elements generate measurement signals of scattered radiation outside the irradiated scanning region,
  • the correction of the scattered radiation thus takes place on the basis would be of correction values q k, which are obtained from a plurality of different measurements i, so that, by the correction value q k respectively represented amplification factor or gain factor of the detector element is substantially free of noise.
  • the corrected measuring signals of the detector elements of the scanning region allow the reconstruction of images in which disturbances due to scattered radiation are largely eliminated in the event that a computer tomograph is used as the X-ray device.
  • the detector elements are arranged to form detector rows, so that the at least one detector row extends within the scanning area parallel to the at least one detector row outside the scanning area.
  • the value of the scattered radiation of the detector elements within the scanning range can be equated with the value of the scattered radiation of that detector element outside the scanning range which is in the same position in the row direction. A separate calculation of the scattered radiation within the scanning range is thus eliminated.
  • the detector line has fewer detector elements outside the scanning area than one of the detector lines within the scanning area, so that scanning gaps occur in line alignment.
  • the value of the scattered radiation at the positions of the sampling gaps is calculated in this case simply by interpolating the values of the scattered radiation of line-wise adjacent detector elements.
  • FIG. 1 shows an inventive X-ray device with a detector and an X-ray source having
  • Measuring arrangement in the form of a computer tomograph, which is suitable for carrying out the calibration or correction method according to the invention, in a perspective overall representation,
  • FIG. 2 shows a section through the detector with a plurality of detector rows shown in FIG. 1, in which part of the detector rows are arranged outside a scanning area and part of the detector rows are arranged within the scanning area,
  • FIG. 3 shows a detector with a plurality of detector rows, in which the detector rows outside of a scanning area have fewer detector elements within the scanning area than the detector rows, in a top view,
  • FIG. 1 shows an X-ray device according to the invention, here a computer tomograph provided with the reference numeral 1, in a perspective overall representation which is suitable for carrying out the calibration or correction method according to the invention.
  • the computer tomograph 1 has a measuring arrangement 2 with an x-ray source in the form of an x-ray tube 5 and with a multicell detector 6.
  • the X-ray tube 5 and the detector 6 are arranged opposite one another in such a way that an X-ray radiation generated by the X-ray tube 5 in the form of a fan-shaped X-ray beam passes through a scanning region 3 and subsequently chd incident on the detector 6.
  • a section through the detector 6 is shown in FIG.
  • the detector has a plurality of detector elements 8, 9 arranged to detector rows 15, 16.
  • the detector rows 15, 16 are arranged on the detector 6 such that a part of the detector rows 15 detects measuring signals of the scanning area 3.
  • Two further detector lines 16 are arranged parallel to the detector lines 15 of the scanning region 3.
  • the detector lines 16 arranged outside the scanning region 3 serve to detect stray radiation 12 from a reference body 4 introduced in the scanning region 3.
  • X-ray tube 5 and detector 6 are rotatably arranged according to the representation of the X-ray device in Figure 1 on a rotating frame 7, so that projections from different projection directions can be detected during a rotational movement.
  • the measurement signals of the detector 6 obtained when carrying out a measurement are transmitted via a data line 17 to a computer unit 18 assigned to the computer tomograph and further processed there.
  • a computer unit 18 assigned to the computer tomograph and further processed there.
  • different programs are installed, which fulfill different functions and which can be activated by a user as needed via a menu.
  • a first program is used for example for calculating the correction factors q k provided for the detection of the scattered radiation detector elements 9.
  • the correction factors q k be the measurement signals S 3.
  • the arranged outside the scanning area 3 the detector elements 9 k generated with which the measured scattered radiation 12 of the reference body 4 positioned in the scanning region 3 is detected.
  • the measurement signals S 3. , K are obtained from a plurality of different measurements i.
  • the measurements i can be carried out from the same and / or from different projection directions. Measurements i from different projection directions have the advantage that when using a rotationally asymmetrical reference body 4, different intensities of the scattered radiation 12 are obtained for different projec- tions. jection directions occur.
  • the measurement signals S 3. , k can be used in this case to determine a non-linear behavior of the correction or amplification factors q k .
  • the reference bodies may, for example, be cylindrical water phantoms 10, 11 with different diameters.
  • the measured signals S 3. , K thus obtained are subsequently used with reference signals R 3 , k ascertained in advance, which represent the actual intensity of the scattered radiation 12 for the respectively used reference body 4; 10; 11, calculated as correction factors q k .
  • the reference signals R 3. , K can be determined by means of a reference measurement with a calibrated detector or by means of a simulation. In the simulation, the spectrum of the X-ray radiation, the interaction of the matter with the X-ray radiation and the signal generation by the respective detector element are modeled by means of mathematical models. In particular, the simulation offers the advantage that the reference signals R 3. , K can be determined for very different reference objects in a short time and with little effort.
  • the reference signals R 3. , K calculated in advance are storable or retrievable in a database 19, so that when the program is called to carry out the calculation of the correction factors q k as a function of the reference body 4; 10; 11 and the measurements to be made available.
  • the correction factor q k of the respective detector element 9 outside the scanning region 3 is calculated, for example, from the following weighted sum: where k is the k-th detector element outside the scanning range, i is the i-th measurement, X 1 is a weighting factor, S is the measuring signal and R is the reference signal of the detector element k and the sum of the weighting factors X 1 over all measurements i is equal to one.
  • weighting factors X 1 such that for large measuring signals S 3 , k the weighting factor X 1 is greater than for small measuring signals S 3 , k. In this case, account is taken of the fact that large amounts of the measurement signals S 3. , K usually have a better signal-to-noise ratio.
  • the respective correction factor can q k can also be calculated according to the following equation:
  • the measurement signals detected by an examination subject can be corrected such that the image artifacts due to scattered radiation are largely suppressed in the reconstructed images.
  • the examination object for example a patient
  • a storage device 20 with a movable tabletop 21.
  • projections are recorded during rotation of the measuring arrangement 2 with a feed or without a simultaneous feed of the table top 21.
  • the measuring signals detected by the detector are transmitted to the arithmetic unit 18 and corrected there according to the following rule:
  • a value of the scattered radiation 12 is determined by multiplication of the measurement signal S 3 , k by the calculated correction factor q k ,
  • a value of the scattered radiation is determined for each of the detector elements 8 arranged within the scanning region 3,
  • the measurement signals corrected in this way can be reconstructed to form an image artifact-free layer or volume image and can be displayed on a display unit 22.
  • the values of the scattered radiation within the scanning range 3 can be equated with those values of the scattered radiation which originate from detector elements 9, which are outside of the scanning region 3 in the row direction 13 are arranged at the same position within the detector row 16. A separate calculation of the scattered radiation within the scanning region 3 is thus eliminated.
  • FIG. 3 shows a detector 6 in which the detector lines 16 outside the scanning region 3 have fewer detector elements within the scanning region 3, so that scanning gaps 14 are formed in the line direction 13.
  • the value of the scattered radiation 12 at the positions of the sampling gaps 14 can in this case be calculated in a simple manner by interpolating the values of the scattered radiation 12 from detector elements 9 adjacent in the line direction 13.
  • the reference signals R 1 , k for a measurement i are shown in the form of a diagram in comparison to uncorrected measurement signals S 1 , which are generated by the detector elements 9 outside the scanning region 3, the x-axis being in line or line ⁇ -direction and in the y-direction the value of the signal is plotted in units of gray values. Differences between the measured scattered radiation or the measured signal S 1 , k and the reference signal R 1 ⁇ indicate that the detector elements have different amplification factors compared to calibrated detector elements. The difference from the reference signal R 1 , k can be corrected by multiplying the measurement signals S 1, mit by the calculated correction factors q k.
  • the correction is achieved by subtracting the logarithmized correction factor q k from the measurement signal S 1 , k.
  • the reference signals R 3 , k necessary for such a correction can be determined by means of simulation or by means of a calibrated detector.
  • the invention relates to a calibration and correction method for an X-ray device 1 and to an X-ray device for carrying out such a calibration or correction method.
  • a measuring arrangement 2 assigned to the X-ray device 1 has a plurality of detector elements 8, 9 which are arranged in such a way that a first part of the detector elements 8 generates measuring signals of the scanning area 3 illuminated by the X-radiation and that a second part of the detector elements 9 are measuring signals of one Scattered radiation generated outside the irradiated scanning region 3.
  • a correction factor q k is calculated from the measurement signals S 3 , k of several measurements i and previously determined reference signals R 3 , k of the scattered radiation 12, so that an actual value of the scattered radiation 12 of the detector element k is calculated can be.
  • images can be generated in which image artifacts of stray radiation are largely suppressed.

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Abstract

L'invention concerne un procédé de calibrage et de correction d'un dispositif radiographique (1) et un dispositif radiographique permettant d'exécuter un tel procédé de calibrage ou de correction. Un système de mesure (2) affecté au dispositif radiographique (1) présente une pluralité d'éléments détecteurs (8,9) placés de telle façon qu'une première partie de ces éléments détecteurs (8) produise les signaux de mesure de la zone de balayage (3) balayée par les rayons X et qu'une deuxième partie des éléments détecteurs (9) produise les signaux de mesure du rayonnement diffusé en dehors de la zone de balayage (3) examinée par radioscopie. Pour chaque élément détecteur k situé hors de la zone de balayage (3), on calcule un facteur de correction qk à partir des signaux de mesure Si, k de plusieurs mesures i et des signaux de référence Rj, k du rayonnement diffusé (12) préalablement déterminés afin de calculer une valeur effective du rayonnement diffusé (12) de l'élément détecteur k. Les facteurs de correction qk ainsi déterminés et le procédé de correction correspondant permettent de produire des images avec une large suppression des artéfacts d'images du rayonnement diffusé.
PCT/EP2006/065341 2005-09-09 2006-08-16 Correction de rayonnement diffuse dans une image radiographique par mesures multiples d'objets de reference WO2007028692A1 (fr)

Applications Claiming Priority (2)

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DE200510043050 DE102005043050A1 (de) 2005-09-09 2005-09-09 Kalibrierverfahren und Korrekturverfahren für eine Röntgeneinrichtung sowie eine Röntgeneinrichtung zur Ausführung eines derartigen Kalibrier-bzw. Korrekturverfahrens
DE102005043050.3 2005-09-09

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DE102008011391A1 (de) * 2008-02-27 2009-10-15 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Röntgencomputertomograph und Verfahren zur Untersuchung eines Objektes mittels Röntgencomputertomographie

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0218923A2 (fr) * 1985-09-16 1987-04-22 General Electric Company Compensation de rayonnement de dispersion appliquée à l'imagerie radiologique
EP0358268A1 (fr) * 1988-09-05 1990-03-14 Koninklijke Philips Electronics N.V. Procédé et dispositif pour la correction d'effets de rayonnement dispersé dans les images à rayons X
US5666391A (en) * 1995-06-26 1997-09-09 Siemens Aktiengesellschaft X-ray examination system with identification of and compensation for subject-produced scattered radiation to reduce image artifacts
WO2002039790A1 (fr) * 2000-11-10 2002-05-16 Siemens Aktiengesellschaft Procede de correction d'un rayonnement diffuse pour un tomodensitometre a rayons x

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2642846A1 (de) * 1976-09-23 1978-03-30 Siemens Ag Roentgenschichtgeraet zur herstellung von transversalschichtbildern
EP0364613B1 (fr) * 1988-10-17 1993-12-29 Siemens Aktiengesellschaft Procédé de fonctionnement d un appareil de tomographie assisté par ordinateur
JP3408848B2 (ja) * 1993-11-02 2003-05-19 株式会社日立メディコ 散乱ｘ線補正法及びｘ線ｃｔ装置並びに多チャンネルｘ線検出器
DE10047720A1 (de) * 2000-09-27 2002-04-11 Philips Corp Intellectual Pty Vorrichtung und Verfahren zur Erzeugung eines Röntgen-Computertomogramms mit einer Streustrahlungskorrektur

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0218923A2 (fr) * 1985-09-16 1987-04-22 General Electric Company Compensation de rayonnement de dispersion appliquée à l'imagerie radiologique
EP0358268A1 (fr) * 1988-09-05 1990-03-14 Koninklijke Philips Electronics N.V. Procédé et dispositif pour la correction d'effets de rayonnement dispersé dans les images à rayons X
US5666391A (en) * 1995-06-26 1997-09-09 Siemens Aktiengesellschaft X-ray examination system with identification of and compensation for subject-produced scattered radiation to reduce image artifacts
WO2002039790A1 (fr) * 2000-11-10 2002-05-16 Siemens Aktiengesellschaft Procede de correction d'un rayonnement diffuse pour un tomodensitometre a rayons x

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