Measuring method and measuring device for point spread function of PET (positron emission tomography) system

Abstract

The invention provides a measuring method and a measuring device for a point spread function of a PET (positron emission tomography) system, and the measuring efficiency and precision can be improved. The measuring method comprises the following step: 11) dividing a scanning range of a detector into a plurality of measuring areas, and selecting a plurality of sampling points in one measuring area; 12) carrying out emission scanning on the sampling points one by one by a line source, and recording a polar coordinate of each sampling point; and 13) obtaining the polar coordinate of each sampling point in other measuring areas according to the polar coordinate of each sampling point in one measuring area, and calculating the point spread function. The measuring device comprises the line source, an angle ruler and a graduated scale, wherein the angle ruler and the graduated scale are respectively used for measuring polar angles and polar diameters of the sampling points; the graduated scale is provided with a datum line labeled with polar diameter scribed lines along a longitudinal direction; the line source is arranged in a vertical surface of the graduated scale, and is vertical to the datum line and can move along the datum line; and the graduated scale can rotate around a measuring center point of the angle ruler in a flat surface parallel to the angle ruler, and can be positioned at a preset angle.

Description

technical field [0001] The invention relates to the field of medical technology, in particular to a method for measuring the point spread function of a PET system. The invention also relates to a measuring device for performing measurements using the above-mentioned measuring method. Background technique [0002] At present, PET (positron emission tomography, positron emission tomography) technology is widely used in the field of medical technology. PET imaging first needs to inject radionuclides into the human body, through the annihilation of the positrons generated by the decay of the nuclide and the negative electrons in the human body to generate Gamma photon pairs, and then use these photon pairs to reconstruct the nuclide concentration distribution of the organ, thus reflecting The metabolism of the human body. [0003] However, in the process of PET imaging, there is a phenomenon of point diffusion, which reduces the resolution and contrast of the image to a large ...

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Problems solved by technology

[0018] However, the above-mentioned existing measurement methods cannot better meet the measurement of the point spread function in the PET system: experiments have shown that the existing measurement methods are time-consuming, and the measurement of each point requires two sliders to move cooperatively. The amount of radiation received is large; the PSF of the sampling point needs to be rotated to obtain the PSF of all points, and Cartesian coordinates are not suitable for rotation transformation. In practice, the Cartesian coordinates obtained by the above measurement method first need to be converted into polar coordinates , and then realize the PSF rotation through the rotation matrix

[0019] In the above-mentioned PSF rotation process, complex coordinate conversion is required, and there may be some approximate processing, which not only reduces the efficiency of measurement, but also affects the measurement accuracy to a certain extent

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