[go: up one dir, main page]

WO2007089962A1 - Detecteur de tomographie gamma eliminant le probleme de la profondeur d'interaction - Google Patents

Detecteur de tomographie gamma eliminant le probleme de la profondeur d'interaction Download PDF

Info

Publication number
WO2007089962A1
WO2007089962A1 PCT/US2007/060365 US2007060365W WO2007089962A1 WO 2007089962 A1 WO2007089962 A1 WO 2007089962A1 US 2007060365 W US2007060365 W US 2007060365W WO 2007089962 A1 WO2007089962 A1 WO 2007089962A1
Authority
WO
WIPO (PCT)
Prior art keywords
radiation
opening
set forth
detection
arcuate surface
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.)
Ceased
Application number
PCT/US2007/060365
Other languages
English (en)
Inventor
Carsten Degenhardt
Herfried Wieczorek
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.)
Koninklijke Philips NV
US Philips Corp
Original Assignee
Koninklijke Philips Electronics NV
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
Application filed by Koninklijke Philips Electronics NV, US Philips Corp filed Critical Koninklijke Philips Electronics NV
Publication of WO2007089962A1 publication Critical patent/WO2007089962A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/16—Measuring radiation intensity
    • G01T1/161—Applications in the field of nuclear medicine, e.g. in vivo counting
    • G01T1/164—Scintigraphy
    • G01T1/1641—Static instruments for imaging the distribution of radioactivity in one or two dimensions using one or several scintillating elements; Radio-isotope cameras
    • G01T1/1644—Static instruments for imaging the distribution of radioactivity in one or two dimensions using one or several scintillating elements; Radio-isotope cameras using an array of optically separate scintillation elements permitting direct location of scintillations
    • 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
    • A61B6/02—Arrangements for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
    • A61B6/03—Computed tomography [CT]
    • A61B6/037—Emission tomography

Definitions

  • the present application relates to the diagnostic imaging systems and methods- It finds particular application in conjunction with the Single Photon Emission Computed Tomography (SPECT) systems and will be described with particular reference thereto. It will be appreciated that the following is also applicable to other like applications.
  • SPECT Single Photon Emission Computed Tomography
  • Nuclear medicine imaging employs a source of radioactivity to image a patient.
  • a radiopharmaceutical is injected into the patient.
  • Radiopharmaceutical compounds contain a radioisotope that undergoes gamma-ray decay at a predictable rate and characteristic energy.
  • One or more radiation detectors are placed adjacent to the patient to monitor and record emitted radiation.
  • the radiation detector is typically a large flat scintillation crystal, such as sodium iodide, having the property of emitting light when struck by gamma photons.
  • Affixed to the rear of this crystal are photomultiplier tubes with associated circuitry to detect the light flashes and to locate their position within the scintillation crystal.
  • Such detector provides a two-dimensional image of radiotracer distribution.
  • the detector is rotated or indexed around the patient to monitor the emitted radiation from a plurality of directions. Based on information such as detected position and energy, the radiopharmaceutical distribution in the body is determined. An image of the distribution is reconstructed to study the circulatory system, radiopharmaceutical uptake in selected organs or tissue, and the like.
  • a collimator is positioned in front of the detector to control the direction of radiation and angular spread from which each element of the detector can receive the radiation.
  • the collimator for each detector defines a single pinhole or a slit which is positioned at some distance from both the object to be examined and the detector.
  • the pinhole or slit functions analogous to an optical pinhole camera, which is equivalent in its performance to an optical lens to "focus" radiation for the region of interest onto the flat detector.
  • the gamma rays which are transmitted through the pinhole or slit reach the center of the flat detector relatively perpendicular. But, at
  • the rays strike the detector at progressively more oblique angles. Because the gamma ray is not converted into a scintillation event until it has progressed some distance into the detector, the scintillations can occur at the locations which are offset from the point of incidence on the detector face.
  • the detectors report the actual coordinates of the scintillation event on the detector that is offset from the point at which the radiation was received by the crystal.
  • the absorption depth or the depth- of-interaction is a quantum mechanical event and not a consistent distance. The variation in the depth of interaction and the variation in incidence angle leads to a positioning error when the position of the gamma event is calculated, which, in turn, leads to image degradation.
  • the present application provides new and improved imaging apparatuses and methods which overcome the above-referenced problems and others.
  • an imaging system is disclosed. At least one radiation detection head is disposed adjacent a field of view to detect radiation from the field of view.
  • the radiation detection head includes a collimator, including an opening, through which radiation rays emanating from the field of view pass.
  • a detection system forms an arcuate surface focused on the collimator opening to detect radiation. Radiation rays received through the collimator opening strike the arcuate surface substantially perpendicular to an incremental area of the arcuate surface at which the radiation strikes.
  • a method of imaging is disclosed. Radiation, that has passed through the opening from a subject disposed in a field of view, is detected with a detection system forming an arcuate surface focused on an opening so that radiation quanta propagate the detection system in a direction substantially perpendicular to the arcuate surface. The detected radiation is converted into electrical signals with an array of light sensitive elements.
  • a diagnostic imaging apparatus supports at least one detector head.
  • Each detector head includes a collimator plate which defines an aperture and an array of detection modules, each module including a face which receives radiation that has passed through the opening and a major axis aligned with the opening.
  • a reconstruction processor reconstructs signals from the detection modules into an image,
  • a detector receives radiation that has passed through an opening along a multiplicity of trajectories, the received radiation traveling along an associated radiation trajectory through the scintillator until the radiation interacts in a quantum mechanical interaction to generate a corresponding scintillation event, the quantum mechanical interactions occurring at non-constant distances along respective trajectories, whereby each scintillation event tends to be offset from a point of incidence of the respective trajectory on the scintillator face in accordance with an angle of the respective trajectory and the distance along the respective trajectory that the scintillation event occurs.
  • Opto-electric transducers convert the scintillation events into electrical signals indicative of the point of incidence on the scintillator face of the respective trajectory, the at least one scintillator and the opto-clcctric transducers being geometrically configured so that the scintillation events are not indicated by the electrical signals as being offset from their respective points of incidence on the scintillator face.
  • FIGURE 1 is a diagrammatic illustration of an imaging system
  • FIGURE 2 is a diagrammatic illustration of one arrangement of detector assembly and a collimator
  • FIGURE 3 is a diagrammatic illustration of another arrangement of detector assembly and a collimator.
  • a nuclear imaging system 10 typically includes a stationary gantry 12 that supports a rotatable gantry 14, One or more detector heads 16 are carried by the rotatable gantry 14 to detect radiation events emanating from a region of interest or examination region or field of view (FOV) 20.
  • the detection heads 16 are arranged generally circumferentially about the field of view 20.
  • an object or subject to be imaged is injected with one or more radiopharmaceuticals or radioisotopes and placed in the examination region 20 supported by a couch 28.
  • radiopharmaceuticals or radioisotopes include Tc-99m, 1-131, Ga-67, and In- 1 1 1.
  • the presence of the radiopharmaceuticals within the object produces emission radiation from the object. Radiation is detected by the detection heads 16 which surround or arc able to be angularly indexed or rotated around the examination region 20 to collect the projection emission data at one or more selected projection directions.
  • the projection emission data e.g.
  • each detection head 16 around the examination region 20 defines the trajectory and energy of each radiation event and are stored in a data memory 32.
  • a reconstruction processor 36 processes the emission data from the data memory 32 into a volumetric image representation.
  • the image representation is stored in an image memory 38 for manipulation by a video processor 40 and display on an image display 42, such as a video monitor, printer, or the like.
  • each detection head 16 includes a detector assembly or detection assembly or system 44 comprising a first or detection array 46 which includes a detector or detector elements or scintillator elements 50, such as one or more scintillator plates, individual scintillation crystals, and the like, and a second array 52 which includes an array of light sensitive elements 54, e.g. photomultiplier tubes, photodiodes, opto-elcctric transducers, and the like. Direct photon to electrical converters, such as semiconductor crystals, CZT elements, and the like, are also contemplated.
  • the detector array includes an array of scintillator elements and diode (or other opto-eiectric element) pairs, each of which defines one detector pixel.
  • the detector pixel that receives radiation defines its location (x, y) on a detector face 56 or trajectory and the strength, e.g. brightness of the scintillation, defines its energy (z).
  • a collimator 60 controls the direction and angular spread, from which each element of the detector 50 via an opening or openings or aperture 62, can receive radiation, i.e., the detector 50 receives radiation along known rays or trajectories.
  • the determined location on the detector 50 at.
  • the examples of the geometries of the collimator 60 are a pinhole collimator with a pinhole opening and a slit collimator with an opening extending in the axial direction Z.
  • the detector elements 50 are positioned along a piecewise continuous arc 68 which is equidistant from the aperture 62.
  • the detector elements 50 are positioned on a spherical segment whose center coincides with a center point of the collimator opening 62.
  • the detector elements 50 are positioned on a circular cylindrical segment whose central axis extends along the slit opening 62 of the slit collimator.
  • the arc 68 is focused on the collimator opening 62.
  • each circular arc segment of detectors receives radiation from a single plane.
  • the detectors is each displaced from the aperture 62 by a common arc radius R.
  • Each detector element 50 of an illustrated pixilated embodiment is shaped as a rectangular prism which is oriented so that a first or longitudinal axis 72 of each detector element 50 is substantially aligned with a ray 74 which passes through the collimator opening 62 and strikes this detector.
  • each detector element 50 comprises a pixel which is linked to a corresponding individual light sensitive element 54 of the detector second array 52.
  • Each detector element 50 together with a corresponding light sensitive element 54 comprises a detector or detection module 78.
  • the detection module 78 includes a semi-conductor detector element for conversion of radiation into electrical signals.
  • a second axis 76 of each detector element 50 is substantially parallel to the arc 68 so that the rays 74 transmitted through the collimator opening 62 strike a corresponding detector element at an angle ⁇ equal to about 90° with respect to the second axis 76. That is, the face 56 of each detector is tangent to the arc 68.
  • Such geometries eliminate the parallax errors.
  • each detector element 50 is larger than the detector element of the embodiment of FIGURE 2.
  • the width w of the detector element face 56 can be equal from about lmm to about 20mm. In one preferred embodiment, the width w of the detector clement face 56 is equal from about 2.5mm to about 10mm. In another preferred embodiment, the width w of the detector face is equal from about 2.5mm to about 5mm.
  • Such larger detector element comprises pixels 80 which each is linked to a corresponding individual light sensitive element or array of light sensitive elements by direct optical coupling or by use of a light guide.
  • the detector clement 50 can be split into larger number of pixels, e.g. smaller pixels, in the manner described above, to increase spatial resolution. This can be done forming a two-dimensional matrix of pixels.
  • the detector element 50 comprises 3 by 3 matrix of pixels 80 which each is linked to a corresponding individual light sensitive element 82, 84, 86.
  • Each detector element 50 together with associated light sensitive elements 82, 84, 86 comprises the detector module 78.
  • the manufacture of the detector assembly 44 with the larger detector modules 78 is substantially simplified as the detector assembly 44 requires fewer detector modules.
  • the first array 46 of the detector assembly 44 includes a continuous detector 50 such as an arcuate sodium iodide plate.
  • the detector 50 includes an array of photomultiplier tubes or other light sensitive elements 54 optically coupled to the scintillator. Signals from the photomultiplier tubes or other light sensitive elements are converted to indications of detection location or radiation trajectory using Anger-logic or the like.

Landscapes

  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • General Health & Medical Sciences (AREA)
  • Medical Informatics (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Optics & Photonics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Molecular Biology (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Nuclear Medicine (AREA)
  • Measurement Of Radiation (AREA)

Abstract

L'invention concerne un détecteur où au moins une tête (16) de détection de radiations est disposée au voisinage d'un champ (20) de vision pour détecter des radiations provenant du champ (20) de vision. La tête (16) de détection de radiations comprend un collimateur (60), comprenant une ouverture (62) à travers laquelle passent les rayons des radiations émanant du champ (20) de vision, et un système (44) de détection formant une surface (68) arquée dont le foyer est situé sur l'ouverture (62) du collimateur servant à détecter les radiations de telle sorte que les rayons des radiations reçus à travers l'ouverture (62) du collimateur frappent la surface arquée sensiblement perpendiculairement à une aire incrémentale de la surface (68) arquée.
PCT/US2007/060365 2006-01-30 2007-01-11 Detecteur de tomographie gamma eliminant le probleme de la profondeur d'interaction Ceased WO2007089962A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US76332606P 2006-01-30 2006-01-30
US60/763,326 2006-01-30

Publications (1)

Publication Number Publication Date
WO2007089962A1 true WO2007089962A1 (fr) 2007-08-09

Family

ID=38016623

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2007/060365 Ceased WO2007089962A1 (fr) 2006-01-30 2007-01-11 Detecteur de tomographie gamma eliminant le probleme de la profondeur d'interaction

Country Status (1)

Country Link
WO (1) WO2007089962A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7829856B2 (en) 2009-03-31 2010-11-09 General Electric Company Apparatus and methods for determining a system matrix for pinhole collimator imaging systems
WO2018077840A1 (fr) 2016-10-28 2018-05-03 Koninklijke Philips N.V. Détecteur de rayonnement gamma à compensation de parallaxe

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4095107A (en) * 1976-04-15 1978-06-13 Sebastian Genna Transaxial radionuclide emission camera apparatus and method
US5021667A (en) * 1988-09-30 1991-06-04 Digital Scintigraphics, Inc. Movable calibration collimator and system and method using same
WO1992015896A1 (fr) * 1991-03-08 1992-09-17 Assistance Publique Systeme de gamma-camera a haute sensibilite

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4095107A (en) * 1976-04-15 1978-06-13 Sebastian Genna Transaxial radionuclide emission camera apparatus and method
US5021667A (en) * 1988-09-30 1991-06-04 Digital Scintigraphics, Inc. Movable calibration collimator and system and method using same
WO1992015896A1 (fr) * 1991-03-08 1992-09-17 Assistance Publique Systeme de gamma-camera a haute sensibilite

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7829856B2 (en) 2009-03-31 2010-11-09 General Electric Company Apparatus and methods for determining a system matrix for pinhole collimator imaging systems
WO2018077840A1 (fr) 2016-10-28 2018-05-03 Koninklijke Philips N.V. Détecteur de rayonnement gamma à compensation de parallaxe
CN109891268A (zh) * 2016-10-28 2019-06-14 皇家飞利浦有限公司 具有视差补偿的伽马辐射探测器
JP2020501116A (ja) * 2016-10-28 2020-01-16 コーニンクレッカ フィリップス エヌ ヴェＫｏｎｉｎｋｌｉｊｋｅ Ｐｈｉｌｉｐｓ Ｎ．Ｖ． 視差効果補償を有するガンマ線検出器
US10989819B2 (en) 2016-10-28 2021-04-27 Koninklijke Philips N.V. Gamma radiation detector with parallax compensation
JP7181194B2 (ja) 2016-10-28 2022-11-30 コーニンクレッカ フィリップス エヌ ヴェ 視差効果補償を有するガンマ線検出器
CN109891268B (zh) * 2016-10-28 2023-10-20 皇家飞利浦有限公司 具有视差补偿的伽马辐射探测器

Similar Documents

Publication Publication Date Title
EP3508885B1 (fr) Système d'imagerie basé sur des événements de coïncidence de photons multi-gamma
RU2543544C2 (ru) Рет-детекторная система с улучшенными характеристиками количественной оценки
CA2252993C (fr) Detecteur pour scanners multimode
EP2847617B1 (fr) Système d'imagerie temp/tep
EP2640270B1 (fr) Système tep/tdm à détecteur unique
JP4897881B2 (ja) ガンマ線検出器とガンマ線再構築方法
US10989819B2 (en) Gamma radiation detector with parallax compensation
EP3513220B1 (fr) Détecteur combinée pour imagerie de rayons x et imagerie nucléaire
US6429434B1 (en) Transmission attenuation correction method for PET and SPECT
US7989771B2 (en) Pinhole SPECT camera with plural detector heads
CN111596336B (zh) 基于缝-孔平板准直器的多伽马光子符合成像系统及方法
CN111638544B (zh) 基于缝孔混合准直器的多伽马光子符合成像系统及方法
US7253416B2 (en) Radiation detector and detection method, and medical diagnostic apparatus employing same
US9012856B2 (en) Gantry-free spect system
US6858849B2 (en) PET apparatus
JP4737292B2 (ja) 核医学診断装置
WO2007089962A1 (fr) Detecteur de tomographie gamma eliminant le probleme de la profondeur d'interaction
US6329657B1 (en) Coincidence transmission source
JP2006284346A (ja) 放射線断層撮影装置
Weber et al. The KFA TierPET: Performance characteristics and measurements
JP2007101341A (ja) 陽電子放出断層撮影装置および陽電子放出断層撮影方法
JP2000249766A (ja) 核医学診断装置
Rahman et al. Performance evaluation of a newly proposed novel L-SPECT system for SPECT imaging
WO2024048515A1 (fr) Dispositif d'acquisition d'image et procédé d'acquisition d'image
CN119867796A (zh) 一种无准直单光子断层成像方法及系统

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 07710055

Country of ref document: EP

Kind code of ref document: A1