Correction information acquisition method for performing attenuation correction on PET image of breath or heart

Abstract

The invention discloses a correction information acquisition method for performing attenuation correction on a PET image of breath or a heart. The method comprises the following steps: acquiring PET detection data with flight time information and a gating signal reflecting periodic movement of the breath or the heart; dividing the PET detection data of each period into B phases; combining the PETdetection data of the same phase in all periods, obtaining the sum of each phase, obtaining a conversion matrix between any phase in the B phases and the basic phase, and establishing a first relational expression between the conversion matrix and the PET radioactivity distribution estimation value corresponding to each phase; obtaining a PET radioactivity distribution estimation model corresponding to the basic phase; and performing iterative processing on the PET radioactivity distribution estimation model to obtain PET radioactivity distribution corresponding to the basic phase. The problemof attenuation artifacts in PET image reconstruction in the prior art can be solved, and accurate quantification of attenuation correction can be guaranteed.

Description

technical field [0001] The invention relates to the field of medical imaging, in particular to a correction information acquisition method and a PET system for performing attenuation correction on PET images of respiration or heart. Background technique [0002] Positron Emission Tomography PET (Positron Emission Tomography) is a high-end nuclear medicine imaging diagnostic equipment. In practice the use of radionuclides (eg 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 situation of life metabolic activities. PET scans are usually accompanied by other modality scans (such as CT, MRI, etc.) to obtain imaging of the patient's anatomical structure. Obtain the tissue density distribution of the patient, calculate the attenuation properties (attenuation coefficient) of the tissue on the radiation, and then apply it to image reconstruction, p...

AI Technical Summary

Problems solved by technology

[0006] 1. After PET data acquisition, each phase is reconstructed separately, so the data available in the reconstruction process is much less than that of static scanning, which leads to a very low signal-to-noise ratio of the final gated image

In this way, even if the blurring effect of object motion on the lesion is removed, the added noise will greatly reduce the detectability of small lesions

[0007] 2. Since the other modality images correspond to a certain phase position, only one phase in the PET multi-phase image obtained by the gating method can match the anatomical structure image, which will still cause the PET image to be matched with other modality images. Quasi-fusion produces deviations (especially near the diaphragm with the largest movement range), and using instantaneous multi-modal images to perform attenuation correction on the average PET image will inevitably cause errors, which will produce local artifacts on the PET image and affect quantitative analysis. , may affect the accurate diagnosis and treatment plan formulation of thoracic and abdominal tumors

When scanning heavy patients, imaging with other modalities will likely not provide a large enough scan field, resulting in truncated attenuation images

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

[0009] 4. When PET is combined with other phantoms, sometimes satisfactory attenuation-corrected images cannot be obtained, such as PET / MR imaging

On the one hand, this increases the workload of doctors. On the other hand, only one frame of images appears in the diagnostic report, and other reconstruction results are not used. This has a lot of information redundancy, wasting data and computing time

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