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

Abstract

The invention discloses a correction information acquisition method for performing attenuation correction on PET images of breathing or heart. The method includes: acquiring PET detection data with time-of-flight information and gating signals reflecting periodic movement of breathing or heart; The PET detection data of a cycle is divided into B phases, the PET detection data of the same phase in all cycles are combined, the sum of each phase is obtained, and the transformation matrix between any phase in the B phases and the basic phase is obtained, and the transformation is established. The first relationship between the matrix and the estimated value of the PET activity distribution corresponding to each phase; obtain the PET activity distribution estimation model corresponding to the basic phase; iteratively process the PET activity distribution estimation model to obtain The PET activity distribution corresponding to the basal phase. The foregoing can solve the problem of attenuation artifacts in PET image reconstruction in the prior art, and can ensure accurate quantification of attenuation correction.

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) is a high-end nuclear medicine imaging diagnostic equipment. Use of radionuclides (such as 18 F. 11 C, etc.) Label metabolites and inject nuclides into the human body, and then perform functional metabolic imaging on patients through PET system to reflect the metabolic activities of life. PET scans are usually matched with other modal scans (such as CT, MRI, etc.) to obtain the imaging of the patient's anatomical structure. The tissue density distribution of the patient is obtained, the attenuation property (attenuation coefficient) of the tissue to the radiation is calculated, and then applied to the image reconstruction, the attenuation correction is performed on the PET data, ...

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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