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Absorption coefficient image estimation method, absorption coefficient image estimation program, and positron ct device equipped with same

An absorption coefficient, positron technology, applied in image data processing, image enhancement, image analysis, etc., can solve problems such as the inability to guarantee the quantification of radioactive images

Inactive Publication Date: 2020-01-14
SHIMADZU SEISAKUSHO CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0023] However, in the prior art of the above-mentioned Non-Patent Document 2, there is the following problem: in principle, it cannot be guaranteed that the finally obtained radioactive image is quantitative

Method used

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  • Absorption coefficient image estimation method, absorption coefficient image estimation program, and positron ct device equipped with same
  • Absorption coefficient image estimation method, absorption coefficient image estimation program, and positron ct device equipped with same
  • Absorption coefficient image estimation method, absorption coefficient image estimation program, and positron ct device equipped with same

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Embodiment 2

[0118] Next, Embodiment 2 of the present invention will be described with reference to the drawings. Figure 4 It is a flowchart showing the processing procedure and data flow of the absorption coefficient image estimation method according to the second embodiment.

[0119] In the above-mentioned embodiment 1, the binarized image of the image μ' is calculated as the object mask image m img , calculate the object mask image m img The projection data of the object to calculate the object mask image m img The binarized data of the projection data is used as the object mask projection data m proj . On the other hand, in Example 2, data obtained by binarizing TOF-PET measurement data converted into projection data format is calculated as subject mask projection data m proj .

[0120] (Step S11) MLACF

[0121] Figure 4 The step S11 is the same as the step S1 of the above-mentioned embodiment 1, so its description is omitted.

[0122] (Step S12) ML-TR or ML-EM

[0123] Fi...

Embodiment 3

[0138] Next, Embodiment 3 of the present invention will be described with reference to the drawings. Figure 5 It is a flowchart showing the processing procedure and data flow of the method for estimating an absorption coefficient image according to the third embodiment when calculating object mask projection data using a radiation image estimated by the MLACF method, Image 6 It shows the processing procedure and data flow of the method for estimating an absorption coefficient image according to Example 3 when calculating object mask projection data using a radioactive image estimated using a reconstruction algorithm different from that of the MLACF method. flow chart.

[0139] In the above-mentioned embodiment 1, the binarized image of the image μ' is calculated as the object mask image m img , to calculate the object mask image m img The projection data, calculate the object mask image m img The binarized data of the projection data is used as the object mask projection ...

Embodiment 4

[0178] Next, Embodiment 4 of the present invention will be described with reference to the drawings. Figure 7 It is a flowchart showing the processing procedure and data flow of the absorption coefficient image estimation method according to the fourth embodiment.

[0179] In the above-mentioned Examples 1 to 3, the MLACF method and the algorithm in which the image obtained by reconstructing the absorption coefficient projection data (absorption coefficient sinogram A' in each of the Examples 1 to 3) is used as the image μ' In combination, the above-mentioned reconstruction calculation process was carried out. On the other hand, in the fourth embodiment, the reconstruction calculation step is implemented by (a) a calculation algorithm (MLAA method) including the image μ' in the unknown.

[0180] (Step S41) MLAA

[0181] In Embodiments 1 to 3 above, in order to simultaneously calculate the image μ' and the radiation image λ', the step S1 of estimating the radiation image λ' ...

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Abstract

In this absorption coefficient image estimation method, an absorption coefficient value is corrected in step S8 (mu=mu' + alpha*[mu]off) on the basis of a mathematical relationship in which the difference between a value of a non-quantitative image [mu]' in a region omega and a known absorption coefficient value (a value of a true absorption coefficient image) can be approximated by alpha*mu off obtained by multiplying an offset image [mu] off by a factor alpha. Therefore, in the absorption coefficient image having the absorption coefficient value [mu] corrected by the step S8 (mu=mu'+ alpha*[mu]off), a systematic error becomes small. As a result, a quantitative absorption coefficient image can be created, and accurate absorption correction of a radioactive image becomes possible.

Description

technical field [0001] The present invention relates to an absorption coefficient image estimation method for estimating an absorption coefficient image from measurement data of a positron CT apparatus (positron emission tomography apparatus), an absorption coefficient image estimation program, and a positron computer equipped with the absorption coefficient image estimation program. CT device. Background technique [0002] A positron CT device, that is, a PET (Positron Emission Tomography: Positron Emission Tomography) device is configured so that only when two gamma rays generated by the annihilation of positrons (Positron) are simultaneously detected by a plurality of detectors (also That is, only when simultaneous counting is performed), the two gamma rays are regarded as effective signals and measured, and a tomographic image of the subject is reconstructed based on the measurement data. Specifically, a radiopharmaceutical containing a positron-emitting nuclide is admi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01T1/161
CPCG06T11/008A61B6/5211G06F17/18G06T7/0014G06T11/006G06T2207/10104
Inventor 小林哲哉
Owner SHIMADZU SEISAKUSHO CO LTD