One-stop liver photon counting CT imaging system and method

Abstract

The invention relates to a one-stop liver photon counting CT imaging system and method.The system comprises a positioning image scanning module, a perfusion scanning module and a delay scanning module, the positioning image scanning module is used for conducting positioning image scanning operation on a patient user, and an abdomen normal position positioning image used for assisting in determining the follow-up perfusion scanning range is obtained; the perfusion scanning module is used for performing multi-energy perfusion scanning operation on the patient user to obtain a perfusion image; and the delay scanning module is used for performing multi-energy delay scanning operation on the patient user to obtain a multi-energy color CT image. Compared with the prior art, one-stop multi-energy CT scanning of the liver is carried out through PCD-CT, low-dose energy CT perfusion imaging and delay period multi-energy color CT images can be obtained, and richer and more accurate data information can be provided for clinic.

Description

Technical Field

[0001] This invention relates to the field of medical image processing technology, and in particular to a one-stop liver photon counting CT imaging system and method. Background Technology

[0002] CT perfusion imaging (CTPI) of the liver obtains time-density curves (TDCs) by continuously scanning the region of interest. Various perfusion parameters, such as hepatic blood flow (BF), blood volume (BV), hepatic arterial perfusion (ALP), portal vein perfusion (PVP), and hepatic perfusion index (HPI), are calculated using different mathematical models. This provides hemodynamic functional information related to microcirculation perfusion in liver lesions, especially hepatocellular carcinoma (HCC) and peritumoral liver tissue. It helps assess changes in microcirculation function before morphological changes in the lesion, and is of significant value in clinical decision-making for early diagnosis, pathological grading prediction, tumor staging, and efficacy evaluation of HCC. However, traditional CT (EID-CT) scans based on an energy integrating detector (EID), such as... Figure 1 As shown, EID-CT requires converting X-rays into visible light, which is then converted into electrical signals by the detector's photodiodes and finally into CT images via an integrated analog-to-digital converter. During this conversion process, X-ray utilization is low, radiation dose is high, and visible light requires a grid to prevent lateral light diffusion, limiting the detector's minimum pixel size and thus restricting image spatial resolution. Due to inherent system noise and component floating noise in the circuitry, more X-rays are needed to improve the signal-to-noise ratio. Therefore, while CTPI images from traditional CT can be used to calculate perfusion parameters, the radiation dose limitation results in extremely high image noise, rendering them unusable for clinical diagnosis. Furthermore, three-phase dynamic contrast-enhanced CT is required to meet imaging diagnostic needs. This increases the patient's radiation dose and the additional contrast agent dosage, increasing the risk of contrast-induced nephropathy, severely limiting its widespread clinical application.

[0003] With the continuous development of CT technology, photon-counting detector-based X-ray energy spectrum CT (PCD-CT) has emerged. For example... Figure 2As shown, PCD-CT can directly read X-ray photon information without being affected by lateral light diffusion, significantly reducing radiation dose. The subdetector unit segmentation greatly improves the spatial resolution of the image. By analyzing X-ray photon information in groups of multiple energy boxes, richer and more accurate energy information than previous energy CT information is obtained, improving the ability to identify lesions with similar density, while reducing the amount of contrast agent used.

[0004] Compared to traditional EID-CT, PCD-CT uses a photon-counting detector (PCD) with the following three advantages: ① It can directly read X-ray photon information without needing a scintillator to convert X-rays into visible light, greatly improving X-ray utilization and overcoming the radiation dose bottleneck of EID-CT, significantly reducing radiation dose without affecting image quality; ② It eliminates the need for segmentation of dark areas, allowing for unlimited sub-detector unit segmentation, thus significantly improving spatial resolution and achieving high-definition imaging; ③ It can segment the X-ray spectrum into multiple energy regions of different energy levels (also known as energy boxes). By using the attenuation characteristics of X-rays at different energy levels to distinguish different substances with similar densities, PCD-CT effectively suppresses X-ray beam hardening artifacts and can accurately determine the atomic number of chemical elements in tissues. This allows for the acquisition of multi-energy color CT images with richer information, higher spectral resolution, and lower dose than previous energy CT methods. It can also use single-energy images at low keV levels to increase image contrast, thereby reducing the amount of contrast agent used. This ensures that PCD-CT can obtain accurate multi-phase CT imaging at ultra-low doses, which can be used for measuring microcirculatory hemodynamic functional data and simultaneously meet the needs of clinical diagnosis.

[0005] However, in the current field of diffuse liver lesions and liver tumors, there is still a lack of an effective liver photon counting CT imaging scheme. It is impossible to obtain low-dose energy CT perfusion imaging and delayed-phase multi-energy color CT images in one stop, which is not conducive to providing more diagnostic information for clinical practice. The existing Chinese patent CN106923856A discloses an image processing method that simultaneously realizes CT perfusion and energy spectrum liver scanning. This method divides the entire scanning phase into 5 segments. The first and third segments are perfusion scanning, and the second, fourth and fifth segments are energy spectrum enhancement scanning. In practical applications, there are still problems of cumbersome operation and large radiation dose. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art by providing a one-stop liver photon counting CT imaging system and method, which can conveniently acquire low-dose energy CT perfusion imaging and delayed-phase multi-energy color CT images in one stop.

[0007] The objective of this invention can be achieved through the following technical solution: a one-stop liver photon counting CT imaging system, comprising a positioning image scanning module, a perfusion scanning module and a delayed scanning module, wherein the positioning image scanning module is used to perform positioning image scanning operations on the patient user to obtain an abdominal anteroposterior positioning image for assisting in determining the range of subsequent perfusion scanning;

[0008] The perfusion scanning module is used to perform multi-energy perfusion scanning on patients to obtain perfusion images.

[0009] The delayed scanning module is used to perform multi-energy delayed scanning on patients to obtain multi-energy color CT images.

[0010] Furthermore, the positioning image scanning module, the perfusion scanning module, and the delayed scanning module specifically perform corresponding scanning operations sequentially according to preset time intervals.

[0011] Furthermore, the perfusion scanning module and the delayed scanning module perform scanning operations according to corresponding preset scanning parameters, which include tube voltage, reference tube current, dynamic exposure dose, image quality level, collimation, layer thickness, interlayer spacing, pitch, rotation time, and image Z-axis length.

[0012] A one-stop liver photon counting CT imaging method includes the following steps:

[0013] S1. For patients in a supine position, perform localization image scanning to obtain the corresponding abdominal anteroposterior localization image, which is used to determine the perfusion scanning range.

[0014] S2. Based on the perfusion scanning range, perform multi-energy perfusion scanning for the patient user to obtain perfusion images;

[0015] S3. Perform multi-energy delayed scanning for patient users to obtain multi-energy color CT images;

[0016] S4. Based on perfusion images and multi-energy color CT images, morphological, hemodynamic and energy CT quantitative information is obtained through post-processing reconstruction.

[0017] Furthermore, the specific process of step S2 includes:

[0018] S21. According to the perfusion scan range, and according to the preset injection volume and injection speed, inject non-ionic contrast agent and normal saline sequentially from the patient's elbow vein.

[0019] S22. When the non-ionic contrast agent injection start time reaches the first preset time, perform multi-energy perfusion scanning operation according to the first preset scanning parameters, and acquire data multiple times during the operation to obtain perfusion images.

[0020] Furthermore, in step S21, the preset injection volume of both the non-ionic contrast agent and the physiological saline is 40 ml, and the preset injection speed of both the non-ionic contrast agent and the physiological saline is 4 ml / s.

[0021] Furthermore, in step S22, the first preset time is 8s, and the first preset scanning parameters are as follows: tube voltage is 90kVp, reference tube current is 73mAs / rot, CARE Dose 4D is used for dynamic exposure dose adjustment, image quality level is 50, collimation is 144×0.44mm, layer thickness is 5mm, interlayer spacing is 3mm, pitch is 1, rotation time is 0.25s, and image Z-axis length is 16cm.

[0022] Furthermore, the process of the multi-energy perfusion scanning operation in step S22 is as follows: First, 20 perfusion scans are performed continuously at a time interval of 1.4s, with each perfusion scan lasting 1.4s;

[0023] Then, six perfusion scans were performed at 2.8-second intervals, with each perfusion scan lasting 1.4 seconds.

[0024] Furthermore, the specific process of step S3 includes: when the perfusion scanning operation ends and the non-ionic contrast agent injection start time reaches the second preset time, performing a multi-energy delayed scanning operation according to the second preset scanning parameters, and acquiring data during the operation to obtain multi-energy color CT images.

[0025] Furthermore, the second preset time is 180s, and the second preset scanning parameters are as follows: tube voltage is 140kVp, reference tube current is 90mAs / rot, CARE Dose 4D is used for dynamic exposure dose adjustment, image quality level is 145, collimation is 144×0.44mm, slice thickness is 5mm, interlayer spacing is 3mm, pitch is 0.5, rotation time is 0.25s, and the image Z-axis length is dynamically adjusted.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] This invention comprises a localization image scanning module, a perfusion scanning module, and a delayed scanning module that sequentially perform corresponding operations. The localization image scanning module performs a localization image scan on the patient to obtain an abdominal anteroposterior localization image to aid in determining the subsequent perfusion scanning range. The perfusion scanning module performs a multi-energy perfusion scan on the patient to obtain perfusion images. Finally, the delayed scanning module performs a multi-energy delayed scan on the patient to obtain multi-energy color CT images. Therefore, using PCD-CT for one-stop multi-energy CT scanning of the liver can simultaneously acquire low-dose energy CT perfusion imaging and delayed-phase multi-energy color CT images, which is beneficial for providing richer and more accurate data information for clinical practice.

[0028] This invention targets perfusion images. On one hand, it obtains morphological and quantitative microcirculatory hemodynamic functional indicators of perfusion color images through post-processing. On the other hand, it can reconstruct multi-phase accurate single-energy CT images with image quality similar to conventional CT scans. Furthermore, it can use these multi-phase single-energy CT images for multi-planar and VR reconstruction to display the relationship between lesions and blood vessels from different orientations and angles. This invention also targets multi-energy color CT images. Through post-processing reconstruction, it can obtain virtual CT plain scan images to replace conventional CT plain scan images. Virtual single-energy images of 40-190keV can be used for routine morphological assessment. It can also obtain energy CT color images such as iodine density maps, atomic number maps, fat maps, and extracellular volume (ECV), along with corresponding quantitative information. This eliminates the need for additional contrast agents and additional three-phase conventional enhanced scans, achieving the dual advantages of low radiation dose and low contrast agent. It also effectively performs microcirculatory hemodynamic and morphological assessments, as well as energy CT quantitative analysis with higher spectral resolution.

[0029] The multi-energy perfusion scanning process designed in this invention is as follows: First, 20 perfusion scans are performed continuously at 1.4-second time intervals, each lasting 1.4 seconds; then, 6 perfusion scans are performed continuously at 2.8-second time intervals, each lasting 1.4 seconds. This achieves data acquisition from 26 perfusion scans, ensuring the stability of the acquired data and improving the accuracy of subsequent post-processing reconstruction.

[0030] Because traditional CT scans have high radiation doses, the actual coverage area of ​​the liver in perfusion scans is relatively small, and additional three-phase contrast-enhanced scans are required to meet routine diagnostic needs. This invention, combined with a photon counting detector (PCD), can directly read X-ray photon information, significantly reducing radiation dose without affecting image quality. Therefore, when performing multi-energy perfusion scans, this invention can fix the Z-axis scan range at 16cm or even adjust it to a longer range depending on the liver lesion, which can completely cover the liver lesion and ensure image quality that meets clinical diagnostic needs at a lower radiation dose. In addition, a virtual plain scan image is reconstructed through delayed-phase spectral scanning for plain scan analysis, eliminating the need for separate plain scans and further reducing radiation dose. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of traditional CT (EID-CT) imaging;

[0032] Figure 2 A schematic diagram of photon counting CT (PCD-CT) imaging;

[0033] Figure 3 This is a schematic diagram of the method flow of the present invention;

[0034] Figure 4 This is a schematic diagram illustrating the application process of an example.

[0035] Figure 5 This is a schematic diagram illustrating the application effect in the example;

[0036] Figures 6-8 This is a schematic diagram of post-processing reconstruction in the embodiment. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0038] Example

[0039] This scheme combines the advantages of photon counting CT and, based on previous research on CT perfusion and CT energy spectrum in diffuse liver lesions and liver tumors, proposes a one-stop liver photon counting CT imaging system and method. The system includes a positioning image scanning module, a perfusion scanning module, and a delayed scanning module. Specifically, the positioning image scanning module, the perfusion scanning module, and the delayed scanning module perform corresponding scanning operations sequentially according to preset time intervals. Furthermore, the perfusion scanning module and the delayed scanning module perform scanning operations according to corresponding preset scanning parameters (including tube voltage, reference tube current, dynamic exposure dose, image quality level, collimation, slice thickness, slice interval, pitch, rotation time, and image Z-axis length).

[0040] Among them, the positioning image scanning module is used to perform positioning image scanning operations on the patient user to obtain an abdominal anteroposterior positioning image to help determine the range of subsequent perfusion scanning;

[0041] The perfusion scanning module is used to perform multi-energy perfusion scanning on patients to obtain perfusion images.

[0042] The delayed scanning module is used to perform multi-energy delayed scanning on patients to obtain multi-energy color CT images.

[0043] Based on the above system, a one-stop liver photon counting CT imaging method is implemented, such as... Figure 3 As shown, it includes the following steps:

[0044] S1. For patients in a supine position, perform localization image scanning to obtain the corresponding abdominal anteroposterior localization image, which is used to determine the perfusion scanning range.

[0045] S2. Based on the perfusion scanning range, perform multi-energy perfusion scanning for the patient user to obtain perfusion images;

[0046] Specifically, based on the perfusion scan range, non-ionic contrast agent and normal saline are injected sequentially from the patient's elbow vein according to the preset injection volume and injection speed.

[0047] When the nonionic contrast agent injection start time reaches the first preset time, a multi-energy perfusion scanning operation is performed according to the first preset scanning parameters, and data is acquired multiple times during the operation to obtain perfusion images;

[0048] S3. Perform multi-energy delayed scanning for patient users to obtain multi-energy color CT images;

[0049] Specifically, when the perfusion scanning operation is completed and the non-ionic contrast agent injection start time reaches the second preset time, a multi-energy delayed scanning operation is performed according to the second preset scanning parameters, and data is acquired during the operation to obtain multi-energy color CT images;

[0050] S4. Based on perfusion images and multi-energy color CT images, morphological, hemodynamic and energy CT quantitative information is obtained through post-processing reconstruction.

[0051] This embodiment applies the above-described scheme, using a Siemens first-generation clinical dual-source photon counting CT scanner (Naeotom Alpha; Siemens Healthcare) for scanning, in single-source, multi-energy mode (Quantum Plus; Siemens Healthcare). During the procedure, the patient is in a supine position, as follows... Figure 4As shown, the scanning scheme includes: first performing a localization image scan, then performing a multi-energy perfusion scan and a delayed-phase scan.

[0052] The perfusion imaging scan range covered 16 cm along the Z-axis, determined by a radiologist with 24 years of experience in CT imaging diagnosis after reviewing the patient's previous examinations on the localization image. For contrast-enhanced scanning, 40 mL of the non-ionic contrast agent Iomeprol (400 mg / mL) was injected via the antecubital vein, followed by 40 mL of normal saline, at a flow rate of 4 mL / s. Perfusion scanning began 8 seconds after contrast agent injection and lasted until 52.94 seconds, acquiring a total of 26 data acquisitions: the first 20 scans were spaced 1.4 seconds apart, and the subsequent 6 scans were spaced 2.8 seconds apart. Multi-energy delayed-phase scanning was performed 180 seconds after contrast agent injection. Detailed parameters for perfusion and delayed-phase scanning are shown in Table 1.

[0053] Table 1

[0054]

[0055] The relevant abbreviations in Table 1 are as follows:

[0056] Br40, Body regular kernel 40;

[0057] QIR, Quantum Iterative Reconstruction;

[0058] Qr40, Quantum Regular Kernel 40;

[0059] SPP stands for Spectral Postprocessed.

[0060] T-3D, Total 3D mixed-energy images;

[0061] VMI, Virtual Monoenergetic Image.

[0062] In Table 1, the perfusion scanning protocol uses a fixed Z-axis length (16cm). Considering that some patients may not be able to fully capture liver lesions due to large or multiple liver tumors, the Z-axis scanning length is adaptively increased during the delayed scanning phase for such patients. However, in the fixed CT perfusion scanning protocol, the contrast agent injection still starts scanning 8s later, and the perfusion scan lasts for 52.94s. The number of perfusion cycles acquired will be reduced according to the Z-axis length.

[0063] In addition, Table 1 lists the image generation parameters corresponding to perfusion scans and delayed-phase scans. For perfusion images, 5mm slice-thick images were generated using convolution kernel Br40, quantum iterative reconstruction (QIR level 3), and T-3D (mixed energy) mode for quantitative analysis of perfusion parameters. 1mm slice-thick images with Br40, quantum iterative reconstruction (QIR level 3), and a single energy level of 50ke were used to reconstruct multi-phase enhanced images. For multi-energy color CT images, 5mm slice-thick images with convolution kernel Br40, quantum iterative reconstruction (QIR level 3), and a single energy level of 50ke were used for routine morphological analysis. The SPP dataset was used for quantitative energy analysis of iodine density maps, atomic number maps, fat maps, and extracellular volume. Figure 5 As shown, morphological, hemodynamic, and energy CT quantitative information can be reconstructed. Figure 5 The relevant information includes:

[0064] ALP, arterial liver perfusion (mL / 100mL / min);

[0065] BF, blood flow (mL / 100mL / min), is the rate at which blood passes through the blood vessels of a tissue area.

[0066] BV, blood volume (mL / 100mL), is the actual volume of blood flowing within blood vessels in a tissue area, which is affected by the size of the blood vessels and the number of open capillaries.

[0067] EAP stands for Early Arterial Phase.

[0068] ECV, extracellular volume;

[0069] FEP, flow-extraction product (mL / 100mL / min), reflects the assessment of vascular permeability;

[0070] HPI, the hepatic perfusion index (%), reflects the proportion of blood supplied by the hepatic artery.

[0071] LAP stands for late arterial phas.

[0072] MTT, mean transit time (s), is the average time it takes for blood to travel from arterial infusion to venous outlet, reflecting the time it takes for the contrast agent to pass through the capillaries of the region of interest.

[0073] PP, portal venous phase;

[0074] PVP, portal venous perfusion (mL / 100mL / min); reflects the amount of portal venous perfusion.

[0075] TTD, or time to drain (s), reflects the time it takes for the contrast agent to drain from the capillaries of the region of interest.

[0076] Therefore, low-dose energy CT perfusion imaging acquired through perfusion scanning can be used to assess macroscopic morphological changes and microcirculatory hemodynamics of liver lesions. It can also provide multi-phase precise virtual single-energy CT images (40-90keV) reconstructed from perfusion images with image quality similar to conventional CT scans, including early arterial phase (assessing arterial variations), late arterial phase (detecting hypervascular lesions), and portal venous phase (assessing portal and hepatic vein vessels, and evaluating the enhancement pattern of intrahepatic lesions). Multiplanar and VR reconstructions can be performed to display the relationship between lesions and blood vessels from different orientations and angles. Using delayed-phase multi-energy CT scanning, 40-190keV virtual single-energy images can be provided for clinical imaging assessment. Furthermore, it can obtain multi-energy color CT information with higher spectral resolution and more precise material differentiation compared to previous energy CT, such as iodine density maps, atomic number maps, fat maps, and extracellular volume (ECV). Furthermore, it eliminates the need for additional contrast agents and repeat three-phase conventional contrast-enhanced scans, thus achieving the dual advantages of low radiation dose and low contrast agent. This facilitates early detection of small hepatocellular carcinomas or occult micrometastases, differential diagnosis of liver neoplastic lesions, prediction of microvascular invasion of hepatocellular carcinoma, assessment of postoperative recurrence of hepatocellular carcinoma, evaluation of the efficacy of various hepatocellular carcinoma treatments, and prediction of early treatment response. It can also assess patient prognosis based on the hepatic perfusion index (HPI) and portal venous perfusion (PVP) of tumor-free liver parenchyma or intrahepatic metastases.

[0077] To verify the effectiveness of this solution, this embodiment employs the above-described scheme, performing corresponding scanning operations and image processing for different patient users. Figure 6 The image shown is a time-density curve (TDCs) acquired from a perfusion CT scan, and a three-phase enhanced image reconstructed from the TDCs. Figure 6 A shows the time-density curves (TDCs) of the abdominal aorta (yellow line), portal vein (green line), and liver parenchyma (red line) during perfusion CT scans. Each point on the curve represents the data acquired at a single time point. Figure 6 In Figure A, the pink, blue, and gray highlighted areas represent the time points for image reconstruction during the early arterial phase (EAP), late arterial phase (LAP), and portal venous phase (PP), respectively. Figure 6 B is an EAP image, reconstructed based on data from when the abdominal aortic TDC peaked. Figure 6 As shown in the pink highlighted area (A), the blood vessels within the tumor are clearly visible. Figure 6 (As indicated by the white arrow in B). Figure 6 C represents the LAP image, reconstructed based on data from the time interval at the "crossover point" of the TDC curves of the abdominal aorta and portal vein. Figure 6 As shown in the blue highlighted area in A, the solid area of ​​the tumor shows obvious enhancement (hollow arrows and triangles), but the intratumoral blood vessels are less visible than in EAP. Figure 6 D is the PP image, reconstructed based on data from the TDC time point at the end of perfusion CT acquisition. Figure 6 (As shown in the gray highlighted area in A). During the LAP and PP phases (shown by the hollow arrows), the typical "fast in, fast out" enhancement pattern of HCC can be observed. Figure 6 E and F in the diagram represent three-dimensional reconstructions of blood vessels, tumors, and liver, as well as preoperative surgical planning diagrams, based on the three-phase reconstruction images.

[0078] Figure 7 The image shown is a perfusion CT scan analysis of a 60-year-old male patient with hepatocellular carcinoma (grade II). The lesion is located in segment S5 of the liver (white arrow). Compared with the adjacent liver parenchyma, the lesion site shows a BF (body fat distribution). Figure 7 A) and BV ( Figure 7 B) Significantly increased (BF, 162.49 mL / 100 mL / min vs. 48.43 mL / 100 mL / min; BV, 12.71 mL / 100 mL vs. 2.96 mL / 100 mL), MTT ( Figure 7 C)(5.24s vs. 3.70s) is prolonged, FEP( Figure 7 D)(108.45mL / 100mL / min vs.46.40mL / 100mL / min), ALP( Figure 7 E)(93.77 mL / 100 mL / min vs. 10.34 mL / 100 mL / min) and HPI ( Figure 7 F (99.98% vs. 9.52%) increased significantly, PVP ( Figure 7 G (0.02 mL / 100 mL / min vs. 100.39 mL / 100 mL / min) decreased significantly. Single-phase extraction of late-stage arterial images at 50 keV ( Figure 7 H) indicates significant heterogeneous enhancement of the lesion, with a portal venous phase 50keV image ( Figure 7 I) The contrast agent clearance is visible to be altered.

[0079] Figure 8 The image shown is a multi-energy image reconstructed from a delayed-phase image (50 keV, QIR grade 3, QIR-Quantum iterative reconstruction) of a 50-year-old female patient with hepatocellular carcinoma (grade III). Figure 8 A represents a virtual non-contrast image (VNC). Figure 8 B represents the delayed-phase image (DP). Figure 8 C represents the energy spectrum curve; Figure 8 D is the iodine map; Figure 8 E stands for Fat map; Figure 8 F represents the atomic number map. All the above images were generated through post-processing of delayed-period SPP (Spectral Post-processing) images. For Figure 8 B and Figure 8 C. In the delayed-phase image, ROIs 1-4 correspond to the solid tumor component, pseudocapsule, fat-containing lesion area within the tumor, and non-tumor liver parenchyma, respectively. The energy dispersive spectroscopy (EDS) curves show that the curves for the fat-containing areas are significantly different from those for the non-fat-containing areas. Figure 8 C). Iodine diagram ( Figure 8 D) Fat map ( Figure 8 E) and atomic number diagram ( Figure 8 F) can clearly distinguish tumor tissue, pseudocapsule, intratumoral fat region and non-tumor liver parenchyma.

[0080] In summary, this approach can conveniently and reliably acquire low-dose energy CT perfusion imaging (for microcirculation hemodynamic and morphological assessment) and delayed-phase multi-energy color CT images (for quantitative analysis of energy CT with higher spectral resolution) in one stop, providing more and more accurate and effective auxiliary data support for clinical practice.

Claims

1. A one-stop liver photon counting CT imaging system, characterized in that, It includes a localization image scanning module, a perfusion scanning module, and a delayed scanning module. The localization image scanning module is used to perform localization image scanning on the patient user to obtain an abdominal anteroposterior localization image to help determine the range of subsequent perfusion scanning. The perfusion scanning module is used to perform multi-energy perfusion scanning on patients to obtain perfusion images. The delayed scanning module is used to perform multi-energy delayed scanning on patients to obtain multi-energy color CT images.

2. The one-stop liver photon counting CT imaging system according to claim 1, characterized in that, The positioning image scanning module, the perfusion scanning module, and the delayed scanning module perform corresponding scanning operations sequentially according to preset time intervals.

3. The one-stop liver photon counting CT imaging system according to claim 1, characterized in that, The perfusion scanning module and the delayed scanning module perform scanning operations according to corresponding preset scanning parameters, which include tube voltage, reference tube current, dynamic exposure dose, image quality level, collimation, layer thickness, interlayer spacing, pitch, rotation time, and image Z-axis length.

4. A one-stop liver photon counting CT imaging method, characterized in that, Includes the following steps: S1. For patients in a supine position, perform localization image scanning to obtain the corresponding abdominal anteroposterior localization image, which is used to determine the perfusion scanning range. S2. Based on the perfusion scanning range, perform multi-energy perfusion scanning for the patient user to obtain perfusion images; S3. Perform multi-energy delayed scanning for patient users to obtain multi-energy color CT images; S4. Based on perfusion images and multi-energy color CT images, morphological, hemodynamic and energy CT quantitative information is obtained through post-processing reconstruction.

5. The one-stop liver photon counting CT imaging method according to claim 4, characterized in that, The specific process of step S2 includes: S21. According to the perfusion scan range, and according to the preset injection volume and injection speed, inject non-ionic contrast agent and normal saline sequentially from the patient's elbow vein. S22. When the non-ionic contrast agent injection start time reaches the first preset time, perform multi-energy perfusion scanning operation according to the first preset scanning parameters, and acquire data multiple times during the operation to obtain perfusion images.

6. The one-stop liver photon counting CT imaging method according to claim 5, characterized in that, In step S21, the preset injection volume of both the non-ionic contrast agent and the physiological saline is 40 ml, and the preset injection rate of both the non-ionic contrast agent and the physiological saline is 4 ml / s.

7. The one-stop liver photon counting CT imaging method according to claim 5, characterized in that, In step S22, the first preset time is 8s. The first preset scanning parameters are as follows: tube voltage is 90kVp, reference tube current is 73mAs / rot, CARE Dose 4D is used for dynamic exposure dose adjustment, image quality level is 50, collimation is 144×0.44mm, layer thickness is 5mm, interlayer spacing is 3mm, pitch is 1, rotation time is 0.25s, and image Z-axis length is 16cm.

8. The one-stop liver photon counting CT imaging method according to claim 5, characterized in that, The process of multi-energy perfusion scanning in step S22 is as follows: First, 20 perfusion scans are performed continuously at a time interval of 1.4s, with each perfusion scan lasting 1.4s. Then, six perfusion scans were performed at 2.8-second intervals, with each perfusion scan lasting 1.4 seconds.

9. A one-stop liver photon counting CT imaging method according to claim 5, characterized in that, The specific process of step S3 includes: when the perfusion scanning operation ends and the non-ionic contrast agent injection start time reaches the second preset time, performing a multi-energy delayed scanning operation according to the second preset scanning parameters, and acquiring data during the operation to obtain multi-energy color CT images.

10. A one-stop liver photon counting CT imaging method according to claim 9, characterized in that, The second preset time is 180s, and the second preset scanning parameters are as follows: tube voltage is 140kVp, reference tube current is 90mAs / rot, CARE Dose 4D is used for dynamic exposure dose adjustment, image quality level is 145, collimation is 144×0.44mm, slice thickness is 5mm, interlayer spacing is 3mm, pitch is 0.5, rotation time is 0.25s, and the image Z-axis length is dynamically adjusted.

Images