Cone-beam XCT (X-ray computed tomography) imaging quality estimation method under sparse projection

Abstract

The invention discloses a cone-beam XCT (X-ray computed tomography) imaging quality estimation method under sparse projection; the method which estimates imaging system quality after a reconstructed three-dimensional image of a simulated body is obtained comprises: selecting a plurality of three-dimensional reconstruction result sections, overlapping and averaging the three-dimensional reconstruction result sections along z-axis direction to obtain an image in a polar coordinate system; performing threshold segmentation, recognizing a target area, and determining the center of the target area by centroid method; setting oversampling pixel size, subjecting pixels in various concentric circle ranges in the image in the polar coordinate system to pixel value averaging, ranking according to distances off the center of circle so as to obtain an oversampling edge spread function (ESF) curve; solving a modulation transfer function; calculating a two-dimensional noise power spectrum of a cone-beam XCT imaging system to obtain a one-dimensional noise power spectrum, and calculating a noise equivalent quantum number NEQ.

Description

technical field

[0001] The invention belongs to the fields of biomedical engineering and computers, and relates to a method for evaluating the imaging quality of cone-beam XCT. Background technique

[0002] In recent years, with the rapid development of the global economy, the average life expectancy is also increasing, and people's dependence on medical care is also increasing. At the same time, people are more pursuing various non-invasive medical methods. As one of the important instruments and equipment in medical imaging, X-ray equipment has naturally become the focus of people's attention. While improving the imaging quality of X-ray equipment, reducing the dose of X-ray radiation is one of the goals pursued by patients and medical researchers. How to produce high-quality and clear images with the minimum X-ray irradiation dose is the focus of X-ray equipment researchers. At present, due to the advantages of fast imaging speed and relatively low radiation dose, cone-...

Examples

Embodiment Construction

[0027] Aiming at the current problems in the quantitative evaluation of the sparse projection cone beam XCT three-dimensional reconstruction method, the present invention proposes a cone beam XCT imaging quality evaluation method under sparse projection, which can accurately obtain the oversampling modulation transfer function and noise power related to the imaging quality Spectrum and noise equivalent quantum numbers. The final technical solution obtained is as follows:

[0028] 1. Set the rotation step angle under sparse projection (for example, rotate the object once every 2 degrees, corresponding to 180 projections), place the designed imaging quality evaluation phantom in the imaging cavity, and then when the object rotates to the set angle , for exposure imaging;

[0029] 2. Using TV regularization method Reconstruct the three-dimensional image of the phantom;

[0030] 3. Follow the steps below to calculate the modulation transfer function MTF of the imaging system u...

technical field

[0001] The invention belongs to the fields of biomedical engineering and computers, and relates to a method for evaluating the imaging quality of cone-beam XCT. Background technique

[0002] In recent years, with the rapid development of the global economy, the average life expectancy is also increasing, and people's dependence on medical care is also increasing. At the same time, people are more pursuing various non-invasive medical methods. As one of the important instruments and equipment in medical imaging, X-ray equipment has naturally become the focus of people's attention. While improving the imaging quality of X-ray equipment, reducing the dose of X-ray radiation is one of the goals pursued by patients and medical researchers. How to produce high-quality and clear images with the minimum X-ray irradiation dose is the focus of X-ray equipment researchers. At present, due to the advantages of fast imaging speed and relatively low radiation dose, cone-...

Examples

Embodiment Construction

[0027] Aiming at the current problems in the quantitative evaluation of the sparse projection cone beam XCT three-dimensional reconstruction method, the present invention proposes a cone beam XCT imaging quality evaluation method under sparse projection, which can accurately obtain the oversampling modulation transfer function and noise power related to the imaging quality Spectrum and noise equivalent quantum numbers. The final technical solution obtained is as follows:

[0028] 1. Set the rotation step angle under sparse projection (for example, rotate the object once every 2 degrees, corresponding to 180 projections), place the designed imaging quality evaluation phantom in the imaging cavity, and then when the object rotates to the set angle , for exposure imaging;

[0029] 2. Using TV regularization method Reconstruct the three-dimensional image of the phantom;

[0030] 3. Follow the steps below to calculate the modulation transfer function MTF of the imaging system u...

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