Linear attenuation coefficient acquisition method and reconstruction method for PET image reconstruction

Abstract

The invention relates to a linear attenuation coefficient acquisition method and reconstruction method for PET image reconstruction, and the coefficient acquisition method comprises the steps: S10, constructing a log-likelihood function L for estimating a PET image without attenuation correction based on collected PET detection data; s20, adjusting and iteratively optimizing the log-likelihood function L according to predefined filtering information and a priori penalty function to obtain a PET image without attenuation correction; s30, mapping the PET image without attenuation correction into a linear attenuation coefficient image mu0 corresponding to the detection target according to a pre-constructed mapping relation; and S40, acquiring a linear attenuation coefficient mu1 for PET image reconstruction based on the corresponding position parameter variation of the scanning bed when the PET detection data is acquired and the linear attenuation coefficient image mu0 corresponding to the detection target. According to the method for obtaining the linear attenuation coefficient, the operation speed can be increased, the stability of a result in PET reconstruction is improved, and meanwhile movement and truncation artifacts of a PET image are avoided.

Description

technical field [0001] The invention relates to the field of medical imaging, in particular to a method for acquiring a linear attenuation coefficient used in image reconstruction in a positron emission computed tomography imaging system, a PET image reconstruction method based on the linear attenuation coefficient, and a PET detection system. Background technique [0002] Positron Emission Tomography PET (Positron Emission Tomography) is a high-end nuclear medicine imaging diagnostic equipment, which uses radionuclides (such as 18 F. 11 C, etc.) Label the metabolites and inject the nuclides into the human body, and then perform functional metabolic imaging on the patient through the PET system to reflect the metabolic activities of life, so as to achieve the purpose of diagnosis. When the PET system collects, the photons will attenuate in the human body before reaching the PET system. Compared with the inside of the object, the coincidence events on the surface of the obje...

AI Technical Summary

Problems solved by technology

Other modalities may not provide a large enough field of view when scanning heavy patients, resulting in truncated attenuation images

This incomplete attenuation information can also produce attenuation artifacts in PET reconstructions

[0009] Finally, satisfactory attenuation-corrected images are sometimes not obtained when PET is co-imaged with other phantoms, such as PET / MR imaging

In contrast to CT imaging, MR primarily utilizes magnetic spin imaging rather than tissue density distribution imaging and therefore does not directly provide accurate information on the nature of tissue attenuation

At present, the algorithm of attenuation correction based on MR imaging is complicated and the accuracy is not high, which easily leads to the generation of attenuation artifacts

In addition, MR cannot image the scanning table and MR coil, which will also affect the subsequent attenuation correction

[0010] At the same time, the application conditions of other modalities also restrict the application of PET imaging. For example, patients with dentures or cardiac pacemakers cannot undergo MR examination, which affects the application of PET / MR.

In addition, CT imaging requires extremely high radiation protection requirements, while MR imaging requires strict nuclear magnetic resonance shielding, which leads to high scanning protection requirements for multi-modal imaging and is not easy to promote

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