PET device, PET-MRI apparatus, and image processing method
First Claim
1. A positron emission computed tomography (PET) device comprising:
- a first PET detector having a ring shape and having a first radius, the first PET detector including a plurality of first scintillators arranged in a ring shape and configured to detect a plurality of gamma rays emitted from positron-emitting radionuclides injected into a subject, the ring shape of the plurality of first scintillators defining an outer circumferential side;
a second PET detector having a ring shape and having a second radius greater than the first radius, the second PET detector including a plurality of second scintillators arranged in a ring shape and configured to detect at least one gamma ray of the plurality of gamma rays that has passed through the first scintillators, the ring shape of the plurality of second scintillators defining an inner circumferential side, wherein the first PET detector and the second PET detector are concentric, wherein the outer circumferential side of the first plurality of scintillators faces the inner circumferential side of the second plurality of scintillators, wherein a pixel size of the second scintillators is larger than a pixel size of the first scintillators, wherein a length of the second PET detector in its axial direction is longer than that of the first PET detector; and
a processor in communication with the plurality of first scintillators and the plurality of second scintillators, the processor configured toacquire first counted information including a detection position, an energy value, and a detection time regarding the plurality of gamma rays detected by one of the first scintillators and acquire second counted information including a detection position, an energy value, and a detection time regarding the at least one gamma ray detected by one of the second scintillators;
when a difference between the detection time comprised by the first counted information and the detection time comprised by the second counted information is within a time window width that is selected to determine whether the first counted information and the second counted information correspond to said at least one gamma ray, generate corrected counted information for said at least one gamma ray by adding the energy value comprised by the second counted information for said at least one gamma ray to the energy value comprised by the first counted information for said at least one gamma ray;
based on the corrected counted information, generate simultaneous counted information based on a combination of the corrected counted information on simultaneous detection of the plurality of gamma rays emitted from the positron-emitting radionuclides; and
reconstruct a PET image in accordance with the simultaneous counted information.
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Accused Products
Abstract
In a PET device, a first detector includes a plurality of first scintillators and detects gamma rays emitted from positron-emitting radionuclides injected into a subject. A second detector is provided on the outer circumferential side of the first detector, includes a plurality of second scintillators arranged in an arrangement surface density lower than that of the first scintillators, and detects gamma rays that have passed through the first detector. A counted information acquiring unit acquires, as first counted information and second counted information, the detection positions, energy values, and detection time regarding gamma rays detected by the first detector and the second detector. Based on the detection time contained in each of the first counted information and the second counted information, an energy value adder generate corrected counted information by summing the energy values contained in the first counted information and the second counted information.
9 Citations
14 Claims
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1. A positron emission computed tomography (PET) device comprising:
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a first PET detector having a ring shape and having a first radius, the first PET detector including a plurality of first scintillators arranged in a ring shape and configured to detect a plurality of gamma rays emitted from positron-emitting radionuclides injected into a subject, the ring shape of the plurality of first scintillators defining an outer circumferential side; a second PET detector having a ring shape and having a second radius greater than the first radius, the second PET detector including a plurality of second scintillators arranged in a ring shape and configured to detect at least one gamma ray of the plurality of gamma rays that has passed through the first scintillators, the ring shape of the plurality of second scintillators defining an inner circumferential side, wherein the first PET detector and the second PET detector are concentric, wherein the outer circumferential side of the first plurality of scintillators faces the inner circumferential side of the second plurality of scintillators, wherein a pixel size of the second scintillators is larger than a pixel size of the first scintillators, wherein a length of the second PET detector in its axial direction is longer than that of the first PET detector; and a processor in communication with the plurality of first scintillators and the plurality of second scintillators, the processor configured to acquire first counted information including a detection position, an energy value, and a detection time regarding the plurality of gamma rays detected by one of the first scintillators and acquire second counted information including a detection position, an energy value, and a detection time regarding the at least one gamma ray detected by one of the second scintillators; when a difference between the detection time comprised by the first counted information and the detection time comprised by the second counted information is within a time window width that is selected to determine whether the first counted information and the second counted information correspond to said at least one gamma ray, generate corrected counted information for said at least one gamma ray by adding the energy value comprised by the second counted information for said at least one gamma ray to the energy value comprised by the first counted information for said at least one gamma ray; based on the corrected counted information, generate simultaneous counted information based on a combination of the corrected counted information on simultaneous detection of the plurality of gamma rays emitted from the positron-emitting radionuclides; and reconstruct a PET image in accordance with the simultaneous counted information. - View Dependent Claims (2, 3, 4, 14)
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5. A positron emission computed tomography-magnetic resonance imaging (PET-MRI) apparatus comprising:
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a static magnetic field magnet configured to generate a static magnetic field in a cylindrical bore; a high-frequency coil configured to detect a magnetic resonance signal emitted from a subject placed in the static magnetic field, in response to application of a high-frequency pulse and a gradient magnetic field to the subject; a first PET detector having a ring shape and having a first radius, the first PET detector including a plurality of first scintillators arranged in a ring shape and configured to detect a plurality of gamma rays that are emitted from positron-emitting radionuclides that are injected into the subject, the ring shape of the plurality of first scintillators defining an outer circumferential side; a second PET detector having a ring shape and having a second radius greater than the first radius, the second PET detector including a plurality of second scintillators arranged in a ring shape and configured to detect at least one gamma ray of the plurality of gamma rays that has passed through the first scintillators, the ring shape of the plurality of second scintillators defining an inner circumferential side, wherein the first PET detector and the second PET detector are concentric, wherein the outer circumferential side of the first plurality of scintillators faces the inner circumferential side of the second plurality of scintillators, wherein a pixel size of the second scintillators is larger than a pixel size of the first scintillators, wherein a length of the second PET detector in its axial direction is longer than that of the first PET detector; and a processor in communication with the high-frequency coil, the plurality of first scintillators, and the plurality of second scintillators, the processor configured to reconstruct an MR image based on the magnetic resonance signal detected by the high-frequency coil; acquire first counted information including a detection position, an energy value, and a detection time regarding the plurality of gamma rays detected by one of the first scintillators and acquire second counted information including a detection position, an energy value, and a detection time regarding the at least one gamma ray detected by one of the second scintillators; when a difference between the detection time comprised by the first counted information and the detection time comprised by the second counted information is within a time window width that is selected to determine whether the first counted information and the second counted information correspond to said at least one gamma ray, generate corrected counted information for said at least one gamma ray by adding the energy value comprised by the second counted information for said at least one gamma ray to the energy value comprised by the first counted information for said at least one gamma ray; based on the corrected counted information, generate simultaneous counted information based on a combination of the corrected counted information on simultaneous detection of the plurality of gamma rays emitted from the positron-emitting radionuclides; and reconstruct a PET image in accordance with the simultaneous counted information. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12)
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13. An image processing method comprising:
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detecting, by a first PET detector having a ring shape and having a first radius, the first PET detector including a plurality of first scintillators arranged in a ring shape to define an outer circumferential side, a plurality of gamma rays that are emitted from positron-emitting radionuclides that are injected into a subject; detecting, by a second PET detector having a ring shape and having a second radius greater than the first radius, the second PET detector including a plurality of second scintillators arranged in a ring shape, at least one gamma ray of the plurality of gamma rays that has passed through the first scintillators, the ring shape of the plurality of second scintillators defining an inner circumferential side, wherein the first PET detector and the second PET detector are concentric, wherein the outer circumferential side of the first plurality of scintillators faces the inner circumferential side of the second plurality of scintillators, wherein a pixel size of the second scintillators is larger than a pixel size of the first scintillators, and wherein a length of the second PET detector in its axial direction is longer than that of the first PET detector; acquiring first counted information including a detection position, an energy value, and a detection time regarding the plurality of gamma rays detected by one of the first scintillators and acquiring second counted information including a detection position, an energy value, and a detection time regarding the at least one gamma ray detected by one of the second scintillators; when a difference between the detection time comprised by the first counted information and the detection time comprised by the second counted information is within a time window width that is selected to determine whether the first counted information and the second counted information correspond to said at least one gamma ray, generating corrected counted information for said at least one gamma ray by adding the energy value contained in the second counted information for said at least one gamma ray to the energy value contained in the first counted information for said at least one gamma ray; generating, as simultaneous counted information, a combination of the corrected counted information on simultaneous detection of the plurality of gamma rays emitted from the positron-emitting radionuclides, based on the corrected counted information; and reconstructing a PET image in accordance with the simultaneous counted information.
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Specification