Gamma ray detector for positron emission tomography (pet) and single photon emisson computed tomography (spect)
First Claim
1. Detector module for a Positron Emission Tomograph (PET) comprising a matrix of scintillator crystals, said matrix having a first side and a second side opposite to said first side, each scintillator crystal having a first end and a second end, said scintillator crystals being oriented parallel to each other, whereby said first end and said second end of each of said scintillator crystals coincide with said first side and said second side of said matrix, respectively;
- a first light sensitive detector producing an electrical signal proportional to the amount of light detected, being optically connected to said first side of said matrix, said first light sensitive detector (6) being position sensitive; and
a second light sensitive detector producing an electrical signal proportional to the amount of light detected, said second light sensitive detector being optically connected to said second side of said matrix, being position sensitive.
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Accused Products
Abstract
The invention relates to a detector module (1) for a Positron Emission Tomograph (PET) and for Single Photon Emission Computed Tomography (SPECT) comprising a matrix (3) of scintillator crystals, said matrix having a first side and a second side opposite to said first side, each scintillator crystal having a first end (14) and a second end (15), said scintillator crystals (2) being oriented parallel to each other, whereby said first end (14) and said second end (15) of each of said scintillator crystals (2) coincide with said first side and said second side of said matrix (3), respectively; a first light sensitive detector (6) producing electrical signal proportional to the amount of light detected, being optically connected to said first side of said matrix (3), said first light sensitive detector (6) being position sensitive; and a second light sensitive detector (7) producing electrical signal proportional to the amount of light detected, said second light sensitive detector (7) being optically connected to said second side of said matrix (3), wherein said second light sensitive detector (7) is positioned sensitive. Using said detector module (1) a method to determine the 3D-coordinates of a point of interaction of a gamma quantum (γ1, γ2) with said detector module (1) is disclosed method. This allows to use signals from compton seattered γ'"'"'s to enhance the sensitivity of a Positron Emission Tomograph scanner provided being composed of said detection modules (1) without parallax errors.
83 Citations
29 Claims
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1. Detector module for a Positron Emission Tomograph (PET) comprising
a matrix of scintillator crystals, said matrix having a first side and a second side opposite to said first side, each scintillator crystal having a first end and a second end, said scintillator crystals being oriented parallel to each other, whereby said first end and said second end of each of said scintillator crystals coincide with said first side and said second side of said matrix, respectively; -
a first light sensitive detector producing an electrical signal proportional to the amount of light detected, being optically connected to said first side of said matrix, said first light sensitive detector (6) being position sensitive; and
a second light sensitive detector producing an electrical signal proportional to the amount of light detected, said second light sensitive detector being optically connected to said second side of said matrix, being position sensitive. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 20)
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15. Positron Emission Tomograph (PET) scanner comprising a number of gamma detector modules characterized in that said gamma detector modules each comprise a detector module comprising
a matrix of scintillator crystals, each scintillator crystal having a first end and a second end, said scintillator crystals being oriented parallel to each other such that all mid points of said scintillator crystals lie in one plane; -
a first light sensitive detector and a second light sensitive detector, each of said light sensitive detectors produces an output signal proportional to the amount of light detected and is position sensitive;
said number of gamma detector modules are regularly angularly spaced on a first and a second circle around an axis of said scanner and oriented such that all midpoints of said scintillator crystals of said detector modules lie in a symmetry plane perpendicular to said axis, whereby the spacing and distribution of said gamma detector modules on said first and said second circle is such that there is no line of sight in a direction perpendicular to said axis radial outward from the cross section of said axis with said symmetry plane, such that there is practically a full azimuthal coverage. - View Dependent Claims (16)
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17. Method for detecting the point of interaction of a gamma ray (γ
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1, γ
2) within a detector module comprisinga matrix of scintillator crystals, each scintillator crystal having a first end and a second end, said scintillator crystals being oriented parallel to each other such that all mid points of said scintillator crystals lie in a plane;
a first light sensitive detector and a second light sensitive detector, each of said light sensitive detectors produces an output signal proportional to the amount of light detected and is position sensitive;
said detector module having a coordinate system associated with, whereby two linear independent coordinate axes χ and
γ
span a χ
γ
-plane coinciding with said plane defined by said midpoints of said scintillator crystals and a third coordinate axis z is oriented perpendicular to said plane whereby an origin of said coordinate system lies in said Xy-plane and a positive direction of said coordinate axis z points to said first light sensitive detector (6), said method comprising the stepsdetermining the coordinates of said point of interaction in said Xy-plane by identifying a first scintillator crystal being hit and using the known coordinates of said first scintillator crystal being hit in said Xy-plane;
determining the coordinate of said point of interaction in said direction (z) perpendicular to said Xy-plane by determining the amount of charge Q1 detected in said first light sensitive detector and an amount of charge Q2 detected in said second light sensitive detector within a coincidence time interval, where the coordinate z is given by where L is the length of said first scintillator crystal. - View Dependent Claims (18, 19)
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1, γ
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21. Hybrid Photo Diodes (HPD) detector comprising
a vacuum containment, said vacuum containment having a flat entrance window at a top and a base at a bottom opposite to said top; -
semi transparent visible light bialkali photocathode deposited inside said vacuum containment at said top parallel to said entrance window;
a semiconductor sensor mounted inside said vacuum containment on said base said semiconductor sensor comprising segments;
a self triggering electronic circuitry for reading out each of said segments separately, being mounted inside said vacuum containment at said base an electron optic providing a imaging of photo electrons from said semi-transparent visible light bialkali photocathode onto said semiconductor sensor - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29)
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Specification