Attenuation rectifying method and system

Abstract

The invention discloses an attenuation rectifying method and system. The attenuation rectifying method includes: collecting standard polyethylene terephthalate (PET) data and a standard computed tomography (CT) image under the standard time phase and nonstandard PET data under various nonstandard time phases; performing image reconstruction on the standard PET data under the standard time phase and the nonstandard PET data under the nonstandard time phases to obtain a standard PET image and nonstandard PET images under the various nonstandard time phases; respectively obtaining the motion information of the nonstandard PET images corresponding to the standard PET image under the various nonstandard time phases; performing motion compensation on the standard CT images according to the various motion information to obtain the nonstandard CT images under the various nonstandard time phases; performing attenuation rectifying on the standard PET data through the standard CT image, and performing attenuation rectifying on the nonstandard PET data under the same time phase through the nonstandard CT images under the various nonstandard time phases so as to obtain the CT images of different phase intervals without repeated CT scanning.

Description

technical field [0001] The invention relates to the field of image processing, in particular to a method and system for attenuation correction. Background technique [0002] Positron Emission Tomography-Computed Tomography (PET-CT) combines PET technology with CT technology. [0003] Positron Emission Tomography (PET) is to mark certain substances necessary in the metabolism of biological life, such as glucose, protein, nucleic acid and fatty acid, etc., with short-lived radioactive sources (such as fluorine 18, Carbon 11, etc.), after being injected into the human body, through the accumulation of the substance in the metabolism, it reflects the situation of life metabolic activities, so as to achieve the purpose of diagnosis. [0004] Computed Tomography (Computed Tomography, CT) is a single-axis ray that penetrates the object under test. Tomographic images are reconstructed to obtain three-dimensional tomographic reconstruction images, and tomographic images of all dire...

AI Technical Summary

Problems solved by technology

Since respiratory movement will drive the movement of organs, tissues or lesions, the difference in acquisition time between PET data and CT data will cause some organs to fail to match

When using CT data to perform attenuation correction on PET data, it will have a certain impact on the Standardized Uptake Value (SUV), and the offset of SUV can reach 24%~30%, and the corrected PET image may produce certain artifacts , affecting clinical diagnosis

[0009] (2) Motion blur caused by respiratory movement during PET data acquisition

[0017] When using the first method to solve the problem of artifacts in attenuation-corrected PET images using CT data, it can only solve the artifacts caused by the mismatch between PET data and CT data information, and cannot solve the problem of motion blur caused by respiratory movement;

[0018] When using the second method to solve the problem of artifacts in PET images with attenuation correction using CT data, it is necessary to perform multiple CT scans on the patient at different time intervals in the respiratory cycle. cause great harm to the body

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