Radiation detector and tof-pet apparatus having the same

Patent metadata

Field	Value
Publication number	US-2017261622-A1
Application number	US-201715412468-A
Country	US
Kind code	A1
Filing date	Jan 23, 2017
Priority date	Mar 14, 2016
Publication date	Sep 14, 2017
Grant date	—

Abstract

A radiation detector provides improved time-resolution under consideration of an incident of a multiple scattering event. An individual comparator 11 extracts a pulse from the detection element 3 a through a total circuit 12 and converts to the time data. In addition, each detection element 3 a comprises the total circuit 12. that outputs the pulse totaling the output of each detection element 3 a, and the total comparator 13 that converts the pulses output from the total circuit 12 to the time data. According to the aspect of the present invention, the time data suitable from each discriminated event is processed, so that the emission-time of fluorescence can be more accurately determined.

First claim

What is claimed is:

1 . A radiation detector, comprising:
a scintillator, wherein a plurality of scintillator crystals that convert a radiation to a fluorescence are arranged in a matrix in a plane and unified; a light detector, having a plurality of individual detection elements corresponding to each said respective scintillator crystal, that detects a fluorescence emitted from said scintillator responsive to said radiation; wherein each output from each said detection element passes through a pathway to a circuit for calculating a fluorescence emission-time of a photoelectric absorption event that is a phenomenon under which fluorescence is emitted from each said respective single scintillator crystal, and to another circuit for calculating a combined fluorescence emission-time of a multiple scattering event that is a phenomenon under which fluorescences are emitted from said plural scintillator crystals; and further comprising: a photoelectric absorption time calculation circuit installed with each detection element, wherein pulses output from said detection element are input through the circuit for the photoelectric absorption event and the fluorescence emission-time relative to said photoelectric absorption event are calculated by converting the pulses to the time data; a total circuit that outputs the pulse totaling outputs from the respective circuits for the multiple scattering event relative to each detection element; and a multiple scattering time calculation circuit that calculates the fluorescence emission-time relative to said multiple scattering event by converting the pulses output from said total circuit to the time data.

1 . radiation detector, according to claim 1 , comprising:
an event discrimination circuit that determines that when a fluorescence is emitted from said scintillator; if the number of said detection elements that output a pulse relative to fluorescence detection is one, the fluorescence is emitted due to said photoelectric absorption event, and if the number of said detection elements that output pulses relative to fluorescence detection is plurality, the fluorescence is emitted due to said multiple scattering event.

3 . The radiation detector, according to claim 1 , comprising:
a fluorescence emission-location calculation circuit that converts the certain pulses to the location data indicating the emission-location of the fluorescence by inputting the pulses output from said detection element through the circuit for the fluorescence emission-location; and wherein a circuit of the output pathways of said detection elements is a circuit to calculate the fluorescence emission-location.

4 . The radiation detector, according to claim 3 , comprising:
a crystal discrimination circuit that determines that if the number of said detection elements that output pulses relative to the fluorescence detection is two, said scintillator crystal corresponding to said detection element that emits a weaker pulse of two pulses is specified as the emission-location of the fluorescence.

5 . A TOF-PET apparatus, comprising:
a radiation detector according to claim 1 and said TOF-PET apparatus further comprising: a detector ring formed by arranging said radiation detectors circularly; and an image generation circuit that performs imaging the distribution of radiopharmaceuticals by changing time-resolution depending on determining whether the radiation is detected by a photoelectric absorption event or a multiple scattering event when said detector ring detects a diminishing radiation pair.

Assignees

• Shimadzu Corp

Inventors

• Tsuda Tomoaki

Classifications

• A61B6/037 Primary

  Emission tomography · CPC title

• G01T1/208 Primary

  Circuits specially adapted for scintillation detectors, e.g. for the photo-multiplier section · CPC title

• A61B6/4266

  characterised by using a plurality of detector units (A61B6/4014 takes precedence) · CPC title

• A61B6/4275

  using a detector unit almost surrounding the patient, e.g. more than 180° · CPC title

• G01T1/1644 Primary

  using an array of optically separate scintillation elements permitting direct location of scintillations (G01T1/1645 takes precedence) · CPC title