Ki mean value calculation method and system based on FDG PET delay scanning

Abstract

The invention relates to a Ki mean value calculation method and system based on FDG PET delayed scanning, and the method comprises the steps: sequentially carrying out the multi-bed whole-body early PET / CT scanning and single-bed delayed PET / CT scanning of a detected object after FDG injection, and obtaining a multi-bed whole-body early PET image and a single-bed delayed PET image; the method comprises the following steps: sketching a region of interest on a multi-bed whole-body early-stage PET image, calculating a blood FDG activity value, and modeling by using a three-exponential function to obtain an input function model curve; and intercepting a single-bed early-stage PET image at the same bed position as the single-bed delay PET image from the multi-bed whole-body early-stage PET image, performing registration to obtain an FDG activity value of a corresponding pixel point or an FDG activity mean value of the region of interest, and further calculating a Ki mean value of the region of interest. The method has the advantages that the method can be directly used for the collection process of FDG PET delayed scanning commonly adopted clinically, repeated blood collection is not needed, the collection bed and collection time of a patient do not need to be additionally increased, the collection duration is shortened, the collection process is simplified, and clinical application and popularization are facilitated.

Description

Technical Field

[0001] This invention relates to the field of emission computed tomography (ECT) technology, and more particularly to a K-line imaging method based on FDG PET delayed scanning. i Mean calculation methods and systems. Background Technology

[0002] Emission computed tomography (ECT) is a non-destructive molecular-level imaging technique widely used clinically for the diagnosis and prognosis of tumors, cardiovascular diseases, and neurodegenerative diseases. It uses a detector to detect gamma photons emitted from an object, combined with image reconstruction algorithms, to non-destructively detect the three-dimensional distribution of radiolabeled drugs within the object. The most widely used ECT techniques in clinical practice include positron emission tomography (PET) and single-photon emission computed tomography (SPECT). 18 F-labeled fluorodeoxyglucose ([ 18 PET imaging of Fluorodeoxyglucose (FDG) is the most widely used emission computed tomography technique in clinical practice for early diagnosis, staging, and prognostic assessment of tumors. It can provide information on glucose metabolism in tissues and organs throughout the body.

[0003] The traditional FDG PET static imaging procedure used in clinical practice is as follows: After the object absorbs FDG for a certain period of time, a response line is obtained by recombination detection of a pair of gamma photons released within the object. After a period of detection, multiple response lines are obtained. The image is reconstructed using analytical or iterative algorithms to obtain a three-dimensional static distribution image of the FDG radioactivity within the object. The radioactivity value of each pixel in the image is converted into a Standard Uptake Value (SUV), calculated as follows: SUV (unit: g / mL) equals the radioactivity value (unit: Bq / mL) divided by the injected dose value (unit: Bq) multiplied by the weight of the object (unit: g). By delineating the region of interest of the tumor, the mean or maximum SUV value within the tumor is calculated for tumor assessment and diagnosis. However, SUV is only a semi-quantitative parameter, as it changes with FDG absorption time and plasma FDG radioactivity. It cannot achieve precise quantification of glucose metabolism in systemic tissues and organs, or even tumors, thus affecting the accuracy of diagnosis and prognostic assessment.

[0004] FDG PET dynamic imaging can yield the dynamic parameter—the net uptake rate constant (hereinafter referred to as K). i FDG PET (Fluorescence Spectrometry) is independent of FDG uptake time and changes in plasma FDG radioactivity, possesses clear physiological significance, and can accurately characterize the metabolic rate of glucose in all tissues and organs, even tumors. It is the gold standard parameter for precise quantification of systemic glucose metabolism using FDG PET. Compared to semi-quantitative SUV (Volume-Specific Detection), precise quantification of K... i FDG PET dynamic imaging can significantly improve the quantitative accuracy and diagnostic capability of tumors for tumor diagnosis and prognostic assessment. Existing FDG PET dynamic imaging methods are time-consuming and complex, including: requiring dynamic scanning for 60 minutes or more immediately after FDG is acquired from the object; dividing the obtained dynamic projection data along the time dimension; reconstructing the image using analytical or iterative algorithms for each frame of projection data to obtain multiple frames of three-dimensional PET images; delineating the region of interest (ROI) in the images; and calculating the average radioactivity over time within the RIO. Simultaneously, multiple consecutive arterial blood samples need to be collected from the patient to measure radioactivity, obtaining its RIO over time curve, hereinafter referred to as the input function curve. Based on the obtained average RIO over time curve and input function curve, the average K0 within the RIO can be calculated using an irreversible two-compartment model or Patlak plot analysis method. i Value. If the region of interest is a tumor, then the average K value within the tumor can be calculated. i The FDG PET dynamic imaging method is used to accurately quantify and assess tumor glucose metabolism. However, the existing FDG PET dynamic imaging method has a long detection time and requires multiple arterial blood samplings, making it unsuitable for clinical practice.

[0005] The applicant has proposed a method for K based on FDG PET images. i A method, system, storage medium, and device for calculating the mean (application number: 202310999999.4) includes: performing a first PET / CT whole-body scan on the object to be detected after FDG injection to obtain a first PET image; performing a second PET / CT whole-body scan after the first PET / CT scan to obtain a second PET image; delineating regions of interest on the first and second PET images, and calculating the blood FDG activity value respectively. and ;according to and Scaling the group input function yields the individual input function. ; Obtain the FDG activity value of the corresponding pixel in the registered image based on the first PET image and the second PET image. and Alternatively, calculate the mean FDG activity of the region of interest in the registered image based on the first and second PET images. and ;according to , , , and Calculate the dynamic parameters K of the region of interest i Mean; or, according to , , , and Calculate K of the region of interest i Mean. This method can obtain the whole-body dynamic parameter K using only two short PET / CT whole-body scans. i K of image and region of interest i The mean value addresses the technical issues of long detection time and the need for multiple arterial blood sampling in existing FDG PET dynamic imaging methods. However, the acquisition process of performing two whole-body PET / CT scans on the same day for the same patient is not widely used in clinical practice. In contrast, the currently prevalent clinical acquisition process is FDG PET delayed scanning. This process includes a whole-body PET image obtained by a multi-bed PET / CT scan after FDG injection, and a single-bed PET / CT scan obtained by a pre-delayed scan after the whole-body scan. The single-bed field of view in the delayed scan can cover the tumor area of ​​the patient that clinicians are focusing on. However, the single-bed field of view in the delayed scan often does not include areas such as the cardiac blood pool or aorta, which are used to delineate the region of interest for calculating blood FDG activity values. Therefore, K i The computational method cannot be applied to the acquisition workflow of FDG PET delayed scanning, which is commonly used in clinical practice. Furthermore, this K... i The calculation method also requires the establishment of a population input function, which needs to be calculated for each individual in the target population by collecting arterial blood or by delineating the region of interest on a traditional FDG PET dynamic image. This is also quite difficult to implement in clinical practice. Summary of the Invention

[0006] (a) Technical problems to be solved In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a K-type PET sensor based on FDG PET delayed scanning. iThe mean calculation method and system solves the technical problems of delayed scanning single-bed field of view not including areas such as the blood pool or aorta, and the need to establish a population input function through individual blood sampling or dynamic image delineation. Existing Ki calculation methods cannot be applied to the clinically common FDG PET delayed scanning process and are difficult to implement clinically.

[0007] (II) Technical Solution To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0008] In a first aspect, the present invention provides a K-ray diffraction method based on FDG PET delayed scanning. i The mean calculation method includes: performing a first PET / CT scan on the subject after FDG injection to obtain multi-bed early whole-body PET images; performing a second single-bed PET / CT scan on the subject after a preset time delay following the first multi-bed PET / CT scan to obtain single-bed delayed PET images; delineating the region of interest on the multi-bed early whole-body PET images; and calculating the blood FDG activity value of the multi-bed early whole-body PET images. The input function model curve is obtained by modeling using a triple exponential function. Extract a single-bed early PET image from the multi-bed whole-body early PET images, capturing the same bed position as the single-bed delayed PET image; obtain the FDG activity value of the corresponding pixel in the registered single-bed early PET image based on the single-bed early PET image and the single-bed delayed PET image. and Alternatively, calculate the mean FDG activity of the region of interest in the registered image based on early and delayed PET images from a single bed. and ;according to , , and Calculate the dynamic parameters K of the region of interest i Mean; or, according to , , and Calculate the dynamic parameters K of the region of interest i Mean.

[0009] Optionally, the according to , , , Calculate the dynamic parameters K of the region of interest i Mean, including: The dynamic parameter K of each pixel in a single-bed PET image is calculated using the following formula. iThe value is used to obtain the single-bed dynamic parameter K. i image: ; in, This refers to the intermediate scanning time for early whole-body PET images in multi-bed settings; This represents the midpoint of a single-bed delayed PET image scan. Is using For the input function model curve The scaling factor used for correction; the scaling factor The specific calculation formula is as follows: ; in, and These represent the start and end times of scanning early whole-body PET images in a multi-bed setting; Then, in the single-bed dynamic parameter K i Delineate the region of interest in the image and calculate K for the region of interest. i Mean.

[0010] Optionally, the step involves obtaining the FDG activity values ​​of corresponding pixels in the registered image based on early PET images and delayed PET images from a single bed. and ,include: Early and delayed PET images from a single bed were registered. The FDG activity values ​​of corresponding individual pixels in the registered early and delayed PET images were denoted as follows: and .

[0011] Optionally, the according to , , , Calculate the dynamic parameters K of the region of interest i Mean, including: The dynamic parameter K of the region of interest is calculated using the following formula. i Mean: ; in, This refers to the intermediate scanning time for early whole-body PET images in multi-bed settings; This represents the midpoint of a single-bed delayed PET image scan. Is using For the input function model curve The scaling factor used for correction; the scaling factor The specific calculation formula is as follows: ; in, and These represent the start and end times of scanning early whole-body PET images in a multi-bed setting.

[0012] Optionally, the region of interest is delineated on the early PET image and the delayed PET image of a single bed, and the first blood FDG activity value of the early PET image of a single bed is calculated respectively. Mean FDG activity of second FDG activity in single-bed delayed PET images ,include: First, image registration is performed on early and delayed PET images from a single bed. Then, regions of interest (ROIs) are selected on the registered early and delayed PET images. Alternatively, the ROI is first delineated on one PET image and then registered to the other PET image. The mean FDG activity of the ROI in the registered early PET image is calculated as the first mean blood FDG activity of the early PET image. The mean FDG activity in the region of interest of the registered single-bed delayed PET image was calculated as the second mean blood FDG activity in the single-bed delayed PET image. .

[0013] Optionally, the input function model curve is obtained by modeling using a three-exponential function. ,include: Use the following formula to calculate: ; in, , and These are the coefficients of the model. Units are , and Units are ; , and These are the feature values ​​of the model, in units of .

[0014] Optionally, the input function model curve is obtained by modeling using a three-exponential function. ,include: Use the following formula to calculate: ; in, , and These are the coefficients of the model. Units are , and Units are ; , and These are the feature values ​​of the model, in units of .

[0015] Secondly, this invention provides a K-type PET sensor based on FDG PET delayed scanning. i The mean calculation system includes: a scanning module for performing a first multi-bed PET / CT scan on the subject after FDG injection to obtain multi-bed early whole-body PET images, and performing a second single-bed PET / CT scan on the subject after a preset delay to obtain single-bed delayed PET images; and a calculation module for delineating regions of interest on the multi-bed early whole-body PET images and calculating the blood FDG activity values ​​in the multi-bed early whole-body PET images. The input function model curve is obtained by modeling using a triple exponential function. Extract a single-bed early PET image from the multi-bed whole-body early PET images, capturing the same bed position as the single-bed delayed scan; obtain the FDG activity value of the corresponding pixel in the registered single-bed early PET image based on the single-bed early PET image and the single-bed delayed PET image. and Alternatively, calculate the mean FDG activity of the region of interest in the registered image based on early and delayed PET images from a single bed. and ;according to , , and Calculate the dynamic parameters K of the region of interest i Mean; or, according to , , and Calculate the dynamic parameters K of the region of interest i Mean.

[0016] Thirdly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the program, when executed, implements the K-axis based on FDG PET delayed scanning as described in any of the first aspects above. i Methods for calculating the mean.

[0017] Fourthly, the present invention provides a storage device, including a storage medium and a processor, wherein the storage medium stores a computer program, and the program, when executed by the processor, implements the K-based FDG PET delayed scanning method described in any of the first aspects above. i Methods for calculating the mean.

[0018] (III) Beneficial Effects The beneficial effects of this invention are: This can be directly applied to the clinically common FDG PET delayed scan acquisition process to obtain the single-bed dynamic parameter K. i K of image and region of interest i The mean value is used to achieve the dynamic parameter K. i The simplified calculation method. Compared with related technologies, this application uses the clinically common FDG PET delayed scanning acquisition process, which does not require additional patient acquisition beds or acquisition time, significantly shortening the acquisition time and simplifying the acquisition process; The blood FDG activity values ​​from PET images acquired at an early single time point, i.e., the blood FDG activity values ​​from early whole-body PET images from multiple beds, are used to scale the three-exponential input function model curve to obtain an input function suitable for the patient. This replaces arterial blood sampling, significantly simplifying the imaging process and improving patient comfort. It can be directly applied in clinical practice to achieve precise quantification of glucose metabolism in tissues, organs, and even tumors. It is simple to operate and is conducive to its widespread clinical application. Attached Figure Description

[0019] Figure 1 The K-based FDG PET delayed scanning method provided in this embodiment of the invention i A flowchart illustrating the mean calculation method; Figure 2 K-based FDG PET delayed scanning provided as another embodiment of the present invention i A flowchart illustrating the mean calculation method; Figure 3 The K-based FDG PET delayed scanning method provided in this embodiment of the invention i Block diagram of the mean calculation system.

[0020] [Explanation of Labels in the Attached Image] 300: K based on FDG PET delayed scan i Mean calculation system; 301: Scanning module; 302: Calculation module. Detailed Implementation

[0021] To better explain and facilitate understanding of the present invention, it will be described in detail below with reference to the accompanying drawings and specific embodiments. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a clearer and more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0022] Firstly, referring to Figure 1 This embodiment provides a K-line based on FDG PET delayed scanning. i Methods for calculating the mean include: S102. Following the clinically common FDG PET delayed scan acquisition procedure, the first multi-bed PET / CT scan was performed on the object to be detected after FDG injection to obtain multi-bed early whole-body PET images.

[0023] Among them, the first multi-bed PET / CT scan was performed on the object to be detected 5-120 minutes after FDG injection.

[0024] S104. After a preset time delay following the completion of the first multi-bed PET / CT scan, the object to be detected is injected with FDG for a second duration, and a second single-bed PET / CT scan is performed to obtain a single-bed delayed PET image.

[0025] The preset time is 50-270 minutes. A second single-bed PET / CT scan is performed on the object under investigation 50-270 minutes after FDG injection. The start time of the second single-bed PET / CT scan must be later than the end time of the first multi-bed PET / CT scan. CT scans can be performed before or after the PET scan for attenuation and scattering correction during PET image reconstruction.

[0026] S106, Delineate the region of interest on early whole-body PET images from multiple beds and calculate the blood FDG activity value from the early whole-body PET images from multiple beds. .

[0027] Specifically, the region of interest for calculating blood FDG activity should be the cardiac blood pool or aorta, etc., and the mean FDG activity within this region should be calculated as the blood FDG activity value. The region of interest can be selected automatically, semi-automatically, or manually. In this step, the region of interest selected is a representative area, such as the blood pool or the aorta.

[0028] S108, using a triple exponential function model to obtain the input function model curve. .

[0029] Specifically, Use the following formula to calculate: ; in, , and These are the coefficients of the model, with representative values ​​as follows: , , ; , and These are the feature values ​​of the model, with representative values ​​being: , , .

[0030] S110, extracting a single-bed early PET image from a multi-bed whole-body early PET image, which is located at the same bed position as a single-bed delayed PET image.

[0031] S112, Obtain the FDG activity value of the corresponding pixel in the registered early PET image of a single bed based on the early PET image and the delayed PET image of a single bed. and .

[0032] Specifically, PET and CT images obtained from multi-bed whole-body early PET / CT scans and single-bed delayed PET / CT scans are registered to perform attenuation and scattering corrections during PET image reconstruction. Based on the bed information recorded in the PET image header file, a single-bed early PET / CT image with the same bed position as the single-bed delayed PET / CT image is extracted from the multi-bed early PET / CT image. The single-bed CT image is downsampled to have the same pixel size and image matrix size as the single-bed PET image. The single-bed early CT image and the single-bed delayed CT image are registered to obtain a single-bed CT image registration matrix. This single-bed CT image registration matrix is ​​applied to the single-bed PET image registered with the CT image to complete the registration of the single-bed early PET image and the single-bed delayed PET image.

[0033] The FDG activity values ​​of corresponding individual pixels on the registered single-bed early PET image and single-bed delayed PET image are denoted as follows: and .

[0034] S114, according to , , , Calculate the dynamic parameters K of the region of interest i Mean.

[0035] The dynamic parameter K of each pixel in a single-bed PET image is calculated using the following formula. i The value is used to obtain the single-bed dynamic parameter K. i image: ; in, This refers to the intermediate scanning time for early whole-body PET images in multi-bed settings; This represents the midpoint of a single-bed delayed PET image scan. Is using For the input function model curve The scaling factor used for correction is calculated using the following formula: ; in, and These represent the start and end times of early whole-body PET scans in a multi-bed setup. Then, the kinetic parameter K in a single-bed setup is... i Delineate the region of interest in the image and calculate K for the region of interest. i Mean.

[0036] This embodiment proposes a K-based method based on FDG PET delayed scanning. i The mean calculation method can be directly applied to the clinically common FDG PET delayed scan acquisition process. It involves performing one multi-bed PET / CT scan and one single-bed PET / CT scan. Then, by outlining the region of interest on the multi-bed early whole-body PET images and calculating the blood FDG activity value, an input function model curve is obtained using a triple exponential function. The blood FDG activity value and the input function model curve are used together, replacing arterial blood sampling and avoiding the complex operation of obtaining the input function from arterial blood collection. Next, a single-bed early PET image at the same bed position as the single-bed delayed scan is extracted from the multi-bed early whole-body PET images and registered with the single-bed delayed PET image. Based on the registered single-bed PET image, the dynamic parameter K of each pixel in the single-bed PET image is calculated according to the formula. i The value is used to obtain the single-bed dynamic parameter K. i Image. This allows for the determination of the single-bed dynamic parameter K. i Select the region of interest on the image to calculate K for that region. i Mean. This achieves the optimization of the dynamic parameter K. iThis method enables precise quantification of glucose metabolism in tissues and organs of interest, and even tumors, through simplified calculations. Furthermore, it can be directly applied to the clinically common FDG PET delayed scanning acquisition process. Compared to traditional FDG PET dynamic imaging, which requires long-duration dynamic acquisition (generally at least 60 minutes) and multiple arterial blood samplings, this method eliminates the need for additional patient beds and acquisition time, and avoids arterial blood sampling. It significantly shortens acquisition time, simplifies the acquisition process, and is easy to operate. Compared to traditional FDG PET dynamic imaging, it is more efficient and conducive to its widespread clinical application.

[0037] Reference Figure 2 This embodiment provides another K-line based on FDG PET delayed scanning. i Methods for calculating the mean include: S202. Following the clinically common FDG PET delayed scan acquisition procedure, the first multi-bed PET / CT scan was performed on the object to be detected after FDG injection to obtain multi-bed early whole-body PET images.

[0038] The first multi-bed PET / CT scan was performed on the object being investigated 5-120 minutes after FDG injection.

[0039] S204. After the first multi-bed PET / CT scan is completed, a preset time is delayed to perform a second single-bed PET / CT scan on the object being detected, resulting in a single-bed delayed PET image.

[0040] A second single-bed PET / CT scan is performed on the object under investigation 50-270 minutes after FDG injection. The start time of the second single-bed PET / CT scan must be later than the end time of the first multi-bed PET / CT scan. The CT scan can be performed before or after the PET scan for attenuation and scattering correction during PET image reconstruction.

[0041] S206, Delineate the region of interest on early whole-body PET images from multiple beds, and calculate the blood FDG activity value from the early whole-body PET images from multiple beds. .

[0042] Specifically, the region of interest for calculating blood FDG activity should be the cardiac blood pool or aorta, etc., and the mean FDG activity within this region should be calculated as the blood FDG activity value. The region of interest can be selected automatically, semi-automatically, or manually. In this step, the region of interest selected is a representative area, such as the blood pool or the aorta.

[0043] S208, using a triple exponential function model to obtain the input function model curve. .

[0044] Specifically, Use the following formula to calculate: ; in, , and These are the coefficients of the model, with representative values ​​as follows: , , ; , and These are the feature values ​​of the model, with representative values ​​being: , , .

[0045] S210, extracting a single-bed early PET image from a multi-bed whole-body early PET image, which is located at the same bed position as a single-bed delayed PET image.

[0046] S212, Calculate the mean FDG activity of the region of interest in the registered image based on early and delayed PET images from a single bed. and .

[0047] Specifically, PET and CT images obtained from multi-bed whole-body early PET / CT scans and single-bed delayed PET / CT scans are registered to correct for attenuation and scattering during PET image reconstruction. Based on the bed information recorded in the PET image header file, a single-bed early PET / CT image with the same bed position as the single-bed delayed PET / CT image is extracted from the multi-bed early PET / CT image. The single-bed CT image is downsampled to have the same pixel size and image matrix size as the single-bed PET image. The single-bed early CT image and the single-bed delayed CT image are registered to obtain a single-bed CT image registration matrix. This single-bed CT image registration matrix is ​​applied to the single-bed PET image registered with the CT image to complete the registration of the single-bed early PET image and the single-bed delayed PET image.

[0048] Regions of interest (ROIs) were selected on both the registered single-bed early PET image and the single-bed delayed PET image. These ROIs could be tumors, target organs, etc. The FDG activity values ​​within these ROIs on the single-bed early PET image and the single-bed delayed PET image were denoted as follows: and .

[0049] S214, according to , , , Calculate the dynamic parameters K of the region of interest i Mean.

[0050] The dynamic parameter K of the region of interest is calculated using the following formula. i Mean: ; in, This refers to the intermediate scanning time for early whole-body PET images in multi-bed settings; This represents the midpoint of a single-bed delayed PET image scan. Is using For the input function model curve The scaling factor used for correction is calculated using the following formula: ; in, and These represent the start and end times of scanning early whole-body PET images in a multi-bed setting.

[0051] This embodiment proposes a K-based method based on FDG PET delayed scanning. i The mean value calculation method can be directly applied to the clinically common FDG PET delayed scan acquisition process. This involves performing one multi-bed PET / CT scan and one single-bed PET / CT scan. Then, the region of interest (ROI) is delineated on the early whole-body PET images from the multi-bed scan, and the blood FDG activity value is calculated. A triple exponential function model is used to obtain the input function model curve. The blood FDG activity value and the input function model curve are used together, replacing arterial blood sampling and avoiding the complex operation of obtaining the input function from arterial blood collection. Next, a single-bed early PET image at the same bed position as the single-bed delayed scan is extracted from the multi-bed early whole-body PET images and registered with the single-bed delayed PET image. Then, the ROI is selected, the mean FDG activity value of the ROI is calculated, and the kinetic parameter K of the ROI is calculated according to the formula. i Mean. This is compared to the calculation of the single-bed dynamic parameter K. i The image can be used to select only the dynamic parameter K of the region of interest, according to actual needs. i This approach reduces workload and increases processing speed by performing calculations. It also enables the calculation of the dynamic parameter K for the region of interest. iThis method enables precise quantification of glucose metabolism in target organs and even tumors through simplified calculations. Furthermore, it can be directly applied to the clinically common FDG PET delayed scanning acquisition process. Compared to traditional FDG PET dynamic imaging, which requires long-term dynamic acquisition (generally at least 60 minutes) and multiple arterial blood samplings, this method does not require additional patient beds or acquisition time, nor does it require arterial blood sampling. It significantly shortens the acquisition time, simplifies the acquisition process, and is easy to operate. Compared to traditional FDG PET dynamic imaging, it is more efficient and conducive to its widespread clinical application.

[0052] Secondly, such as Figure 3 As shown, this embodiment provides a K-type PET sensor based on FDG PET delayed scanning. i The mean calculation system 300 includes a scanning module 301 and a calculation module 302. The scanning module 301, following the clinically common FDG PET delayed scanning acquisition procedure, performs a first multi-bed PET / CT scan on the subject after FDG injection to obtain multi-bed early whole-body PET images. After the first multi-bed scan, a second single-bed PET / CT scan is performed on the subject after a preset delay to obtain single-bed delayed PET images. The calculation module 302 is used to delineate the region of interest on the multi-bed early whole-body PET images and calculate the blood FDG activity value in the multi-bed early whole-body PET images. The input function model curve is obtained by modeling using a triple exponential function. Extract a single-bed early PET image from the multi-bed whole-body early PET images, capturing the same bed position as the single-bed delayed scan; obtain the FDG activity value of the corresponding pixel in the registered single-bed early PET image based on the single-bed early PET image and the single-bed delayed PET image. and Alternatively, calculate the mean FDG activity of the region of interest in the registered image based on early and delayed PET images from a single bed. and ;according to , , and Calculate the dynamic parameters K of the region of interest i Mean; or, according to , , and Calculate the dynamic parameters K of the region of interest i Mean. According to the K value based on FDG PET delayed scanning provided in this embodiment... iThe mean calculation system, because it is used to implement the K-value based on FDG PET delayed scanning provided in the first aspect embodiment of the present invention... i The steps of the mean calculation method, therefore, this K based on FDG PET delayed scan i The mean calculation system has the K-value based on FDG PET delayed scan. i The full technical benefits of the mean calculation method will not be elaborated here.

[0053] Thirdly, embodiments of the present invention provide a computer-readable storage medium having a computer program stored thereon, wherein the program, when executed, implements the K-based FDG PET delayed scanning method described in any of the first aspects above. i Methods for calculating the mean.

[0054] Fourthly, embodiments of the present invention provide a storage device, including a storage medium and a processor, wherein the storage medium stores a computer program, and when the program is executed by the processor, it implements the K-based FDGPET delayed scan method described in any of the first aspects above. i Methods for calculating the mean.

[0055] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0056] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, then this invention should also include these modifications and variations.

[0057] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A K i The mean value calculation method is characterized in that, The method comprises: performing a first multi-bed PET / CT scan on the object to be detected after injection of FDG to obtain a multi-bed whole-body early PET image; delaying a preset time after the first multi-bed PET / CT scan is completed, and performing a second single-bed PET / CT scan on the object to be detected to obtain a single-bed delayed PET image; delineate a region of interest on the multi-bed whole body early PET image, calculate blood FDG activity values for the multi-bed whole body early PET image ; Using a three-index function to model the input function model curve ; cutting a single-bed early PET image of the same bed position as the single-bed delayed PET image from the multi-bed whole-body early PET image; FDG activity values of corresponding pixels on the registered single bed early PET image according to the single bed early PET image and the single bed late PET image and ; or, FDG activity mean values of regions of interest on the registered images calculated according to the single bed early PET image and the single bed late PET image and ; According to , , and the kinetic parameter K of the region of interest is calculated i the mean; or, according to , , and the kinetic parameter K of the region of interest is calculated i the mean.

2. The K i The mean value calculation method is characterized by comprising the steps of: The according to , , , calculating the kinetic parameter K of the region of interest i mean, comprising: The kinetic parameter K for each pixel of the single bed PET image is calculated according to the following equation i The kinetic parameter K for each pixel of the single bed PET image is calculated according to the following equation i Image: ； wherein, is the middle time of the scan for the multi-bed whole-body early PET image; is the middle time of the scan for the single-bed delay PET image; is the scaling factor for correcting the input function model curve is the scaling factor for correcting the input function model curve is the scaling factor for correcting the input function model curve The specific calculation formula of the scaling factor is as follows: ； wherein, and are the start and end time of the scan of the multi-bed whole-body early PET image, respectively. In single bed kinetic parameters K i Draw the region of interest in the image, calculate K of the region of interest i Mean.

3. The K i The mean value calculation method is characterized by comprising the steps of The FDG activity value of the corresponding pixel point on the registered image is obtained according to the single-bed early PET image and the single-bed delay PET image and comprise: The single-bed early PET image and the single-bed delay PET image are registered, and the FDG activity values of the corresponding single pixels on the registered single-bed early PET image and the single-bed delay PET image are respectively denoted as and .

4. The K i The mean value calculation method is characterized in that, The according to , , , calculating kinetic parameters K of a region of interest i mean, comprising: The kinetic parameter K of the region of interest is calculated according to the following formula i Mean: ； in, This refers to the intermediate scanning time for early whole-body PET images in multi-bed settings; This represents the midpoint of a single-bed delayed PET image scan. Is using For the input function model curve The scaling factor used for correction; the scaling factor The specific calculation formula is as follows: ； wherein, and are the start and end time of the scan of the multi-bed whole-body early PET image, respectively.

5. The K i The mean value calculation method is characterized in that, said delineating a region of interest on the single bed early PET image and the single bed delay PET image, calculating a first blood FDG activity value of the single bed early PET image and a second FDG activity mean value of the single bed delay PET image , comprising: performing image registration on the single-bed early PET image and the single-bed delayed PET image first, and then selecting a region of interest on the registered single-bed early PET image and the single-bed delayed PET image; or, first drawing a region of interest on one of the PET images, and then registering the drawn region of interest to the other PET image; calculating a mean FDG activity of a region of interest of the registered early single bed PET image as a first blood FDG activity mean of the early single bed PET image ; The mean FDG activity of the region of interest of the registered single bed delay PET image is calculated as the second blood FDG activity mean of the single bed delay PET image .

6. The K i The mean value calculation method is characterized in that, The input function model curve is obtained by using a three-index function modeling , comprising: The calculation was performed using the following formula: ； wherein , and are coefficients of the model, in units of , and in units of ; , and are eigenvalues of the model in units of .

7. A K based on FDG PET delay scan i A mean value calculation system characterized by comprising: The method comprises: a scanning module, configured to perform a first multi-bed PET / CT scan on the object to be detected after injection of FDG to obtain a multi-bed whole-body early PET image, and delay a preset time after the first multi-bed PET / CT scan is completed, and perform a second single-bed PET / CT scan on the object to be detected to obtain a single-bed delayed PET image; A computing module is configured to delineate a region of interest on the multi-bed whole-body early PET image, and calculate blood FDG activity values of the multi-bed whole-body early PET image ; an input function model curve is obtained by modeling using a three-exponential function ; a single-bed early PET image of the same bed position as the single-bed delay PET image is cut from the multi-bed whole-body early PET image; and FDG activity values of corresponding pixel points on the registered single-bed early PET image are obtained according to the single-bed early PET image and the single-bed delay PET image and ; or, a mean FDG activity value of a region of interest on the registered image is calculated according to the single-bed early PET image and the single-bed delay PET image and ; a kinetic parameter K , , and of the region of interest is calculated according to i a mean value; or, a kinetic parameter K , , and of the region of interest is calculated according to i a mean value.

8. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program, when executed by the processor, implements the method of any one of claims 1 to 6 for determining a K i Mean calculation method.

9. A storage device comprising a storage medium and a processor, the storage medium storing a computer program, characterized in that, The processor implements the computer program to realize the K i Mean calculation method.

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