Cerebral perfusion computed tomography(PCT)is an important imaging modality for evaluating cerebrovascular diseases and stroke symptoms.With widespread public concern about the potential cancer risks and health hazard...Cerebral perfusion computed tomography(PCT)is an important imaging modality for evaluating cerebrovascular diseases and stroke symptoms.With widespread public concern about the potential cancer risks and health hazards associated with cumulative radiation exposure in PCT imaging,considerable research has been conducted to reduce the radiation dose in X-ray-based brain perfusion imaging.Reducing the dose of X-rays causes severe noise and artifacts in PCT images.To solve this problem,we propose a deep learning method called NCS-Unet.The exceptional characteristics of non-subsampled contourlet transform(NSCT)and the Sobel filter are introduced into NCS-Unet.NSCT decomposes the convolved features into high-and low-frequency components.The decomposed high-frequency component retains image edges,contrast imaging traces,and noise,whereas the low-frequency component retains the main image information.The Sobel filter extracts the contours of the original image and the imaging traces caused by the contrast agent decay.The extracted information is added to NCS-Unet to improve its performance in noise reduction and artifact removal.Qualitative and quantitative analyses demonstrated that the proposed NCS-Unet can improve the quality of low-dose cone-beam CT perfusion reconstruction images and the accuracy of perfusion parameter calculations.展开更多
BACKGROUND Hepatopulmonary syndrome (HPS) is an arterial oxygenation defect induced by intrapulmonary vascular dilatation (IPVD) in the setting of liver disease and/or portal hypertension.This syndrome occurs most oft...BACKGROUND Hepatopulmonary syndrome (HPS) is an arterial oxygenation defect induced by intrapulmonary vascular dilatation (IPVD) in the setting of liver disease and/or portal hypertension.This syndrome occurs most often in cirrhotic patients(4%-32%) and has been shown to be detrimental to functional status,quality of life,and survival.The diagnosis of HPS in the setting of liver disease and/or portal hypertension requires the demonstration of IPVD (i.e.,diffuse or localized abnormally dilated pulmonary capillaries and pulmonary and pleural arteriovenous communications) and arterial oxygenation defects,preferably by contrast-enhanced echocardiography and measurement of the alveolar-arterial oxygen gradient,respectively.AIM To compare brain and whole-body uptake of technetium for diagnosing HPS.METHODS Sixty-nine patients with chronic liver disease and/or portal hypertension were prospectively included.Brain uptake and whole-body uptake were calculated using the geometric mean of technetium counts in the brain and lungs and in the entire body and lungs,respectively.RESULTS Thirty-two (46%) patients had IPVD as detected by contrast-enhancedechocardiography.The demographics and clinical characteristics of the patients with and without IPVD were not significantly different with the exception of the creatinine level (0.71±0.18 mg/dL vs 0.83±0.23 mg/dL;P=0.041),alveolararterial oxygen gradient (23.2±13.3 mmHg vs 16.4±14.1 mmHg;P=0.043),and arterial partial pressure of oxygen (81.0±12.1 mmHg vs 90.1±12.8 mmHg;P=0.004).Whole-body uptake was significantly higher in patients with IPVD than in patients without IPVD (48.0%±6.1%vs 40.1%±8.1%;P=0.001).The area under the curve of whole-body uptake for detecting IPVD was significantly higher than that of brain uptake (0.75 vs 0.54;P=0.025).The optimal cut-off values of brain uptake and whole-body uptake for detecting IPVD were 5.7%and 42.5%,respectively,based on Youden’s index.The sensitivity,specificity,and accuracy of brain uptake> 5.7%and whole-body uptake> 42.5%for detecting IPVD were23%,89%,and 59%and 100%,52%,and 74%,respectively.CONCLUSION Whole-body uptake is superior to brain uptake for diagnosing HPS.展开更多
AIM:To assess prospectively parameters of computed tomography perfusion(CT p) for evaluation of vascularity of liver metastases from neuroendocrine tumors.METHODS:This study was approved by the hospital's institut...AIM:To assess prospectively parameters of computed tomography perfusion(CT p) for evaluation of vascularity of liver metastases from neuroendocrine tumors.METHODS:This study was approved by the hospital's institutional review board.All 18 patients provided informed consent.There were 30 liver metastases from neuroendocrine tumors.Patients were divided into three groups depending on the appearance of the liver metastases at the arterial phase of morphological CT(hyperdense,hypodense and necrotic).Sequential acquisition of the liver was performed before and for 2 min after intravenous injection of 0.5 mg/kg contrast medium,at 4 mL/s.Data were analyzed using deconvolution analysis to calculate blood flow(BF),blood volume(BV),mean transit time(MTT),hepatic arterial perfusion index(HAPI) and a bi-compartmental analysis was performed to obtain vascular permeability-surface area product(PS).Post-treatment analysis was performed by a radiologist and regions of interest were plotted on the metastases,normal liver,aorta and portal vein.RESULTS:At the arterial phase of the morphological CT scan,the aspects of liver metastases were hyperdense(n=21),hypodense(n=7),and necrotic(n=2).In cases of necrotic metastases,none of the CT p parameters were changed.Compared to normal liver,a significant difference in all CT p parameters was found in cases of hyperdense metastases,and only for HAPI and MTT in cases of hypodense metastases.No significant difference was found for MTT and HAPI between hypo-and hyperdense metastases.A significant decrease of PS,BV and BF was demonstrated in cases of patients with hypodense lesions PS(23±11.6 mL/100 g per minute) compared to patients with hyperdense lesions;PS(13.5±10.4 mL/100 g per minute),BF(93.7±75.4 vs 196.0±115.6mL/100 g per minute) and BV(9.7±5.9 vs 24.5 10.9 mL/100 g).CONCLUSION:CT p provides additional information compared to the morphological appearance of liver metastases.展开更多
Objective: To study the value of spiral CT perfusion parameters for evaluating acute pancreatitis and their correlation with inflammatory factor and JAK2/STAT3 signaling pathway. Methods: Patients with acute pancreati...Objective: To study the value of spiral CT perfusion parameters for evaluating acute pancreatitis and their correlation with inflammatory factor and JAK2/STAT3 signaling pathway. Methods: Patients with acute pancreatitis and patients with pancreatic trauma who underwent surgical resection in Liaocheng Dongchangfu People's Hospital between May 2014 and March 2017 were selected and enrolled in the AP group and the control group of the research respectively;spiral CT perfusion scanning was conducted before surgery to measure the blood flow (BF), blood volume (BV), and mean transit time (MTT), and the serum was collected to determine the contents of inflammatory factors;pancreatitis tissue and normal pancreatic tissue were collected after surgical resection to determine the expression of JAK2/STAT3 signal molecules. Results: pancreatic tissue BF and BV levels of AP group were significantly lower than those of control group while MTT level was not different from that of control group;CRP, PCT, HMGB-1, Ghrelin and sTREM-1 contents in serum as well as JAK2, STAT3, Bcl-2 and Bcl-xL mRNA expression in pancreatic tissue of AP group were significantly higher than those of control group and negatively correlated with BF and BV levels in pancreatic tissue. Conclusion: Spiral CT perfusion parameters BF and BV can reflect the microcirculatory disorder of acute pancreatitis and are associated with the increased secretion of inflammatory factors and the activation of JAK2/STAT3 signaling pathway in the course of disease.展开更多
目的观察肝硬化(HC)合并原发性肝癌(PLC)患者CT动态增强扫描变化,分析其诊断价值。方法回顾性分析2020年4月—2022年7月我院125例HC患者资料,所有受试者均行病理组织学检测及CT动态增强扫描,统计所有患者病灶大小及分布情况,CT动态增强...目的观察肝硬化(HC)合并原发性肝癌(PLC)患者CT动态增强扫描变化,分析其诊断价值。方法回顾性分析2020年4月—2022年7月我院125例HC患者资料,所有受试者均行病理组织学检测及CT动态增强扫描,统计所有患者病灶大小及分布情况,CT动态增强扫描动脉期、静脉期、延迟期病灶检出情况,以病理检查为金标准,分析CT动态增强扫描对HC患者PLC的诊断价值、HC患者与HC并PLC患者血流灌注参数大小及不同肝功能CTP分级下血流灌注参数变化。结果125例HC患者共检出161个病灶,其中直径<1 cm 8个,1~3 cm 53个,4~5 cm 63个,>5 cm 37个,肝右前叶、肝右后叶者居多,分别为45及69个;CT动态增强扫描动脉期检出病灶149个,检出率92.55%;门脉期检出病灶134个,检出率83.23%;延迟期检出病灶142个,检出率88.20%;125例HC患者中病理学检查显示75例PLC阳性,50例PLC阴性,CT动态增强扫检测HC并PLC的敏感度为94.67%,特异度为94.00%,准确率为94.40%,阳性预测值为95.95%,阴性预测值为92.16%,Kappa值为0.884,具有较高的一致性;HC组HAP、HPI值均显著低于HC并PLC组,PVP、TLP值均显著高于HC并PLC组(P<0.05);125例HC并PLC患者中CTP A级41例,CTP B级46例,CTP C级38例,CTP A级HAP、HPI值显著低于CTP B、C级(P<0.05),PVP、TLP值均显著高于CTP B、C级(P<0.05),CTP B级HPI值与CTP C级比较,差异均无统计学意义(P>0.05)。结论CT动态增强扫描可多方位多角度显示HC病灶情况,且对PLC具有较好的诊断价值,其中肝脏血流灌注参数具有一定的特征性,可为PLC诊断和肝功能分级提供参考。展开更多
Background Multi-slice CT liver perfusion has been widely used in experimental studies of hemodynamic changes in liver lesions, and is usually performed as an adjunct to a conventional CT examination because of its hi...Background Multi-slice CT liver perfusion has been widely used in experimental studies of hemodynamic changes in liver lesions, and is usually performed as an adjunct to a conventional CT examination because of its high temporal and spatial resolution, simple protocol, good reproducibility, and ability to measure hemodynamic changes of liver tissues at the capillary level. Experimental rat models, especially those of induced liver cancer, are often used in studies of hemodynamic changes in liver cancer. Carcinogenesis in rats has a similar pathological progression and characteristics resembling those in human liver cancer; as a result, rat models are often used as ideal animal models in the study of human liver cancer. However, liver perfusion imaging in rats is difficult to perform, because rats＇ livers are so small that different concentrations, flow rates, and dose of contrast agents during the CT perfusion scanning can influence the quality of liver perfusion images in rats. The purpose of this study, therefore, was to investigate the optimal scan protocol for the imaging of hepatic perfusion using a deconvolution mathematical method in rats by comparing the results of rats in different injection conditions of the contrast agent, including concentration, rate and time. Methods Plain CT scan conditions in eighty 2-month-old male Wistar rats were 5.0 mm slice thickness, 5.0 mm interval, 1.0 pitch, 120 kV tube voltage, 60 mA tube current, 512x512 matrix, and FOV 9.6 cm. Perfusion scanning was carried out with different concentrations of diatrizoate （19%, 38%, 57%, and 76%）, different injection rates （0.3 and 0.5 ml/s）, and different injection times （1, 2-3, 4-5, and 6 seconds）. The above conditions were randomly matched and adjusted to determine the best perfusion scan protocol. Three-phase contrast-enhanced scanning was performed after CT perfusion. Histological examination of the liver tissues with hematoxylin and eosin stains was done after CT scanning. Results When the concentration of the contrast agent was 19% or 38%, no pseudo-color map was created. The viscosity increased when the concentration of the contrast agent was 76%; so it is difficult to inject the contrast agent at such a high concentration. Also no pseudo-color map was generated when the injection time was short （1, 2-3, and 4-5 seconds） or the injection rate was low （0.3 ml/s）. The best perfusion images and perfusion parameters were obtained during 50 seconds scanning. Each rat was given an injection of 57% diatrizoate at 0.5 mils via the tail vein using a high-pressure syringe for 6 seconds. The perfusion parameters included hepatic blood flow （HBF）, hepatic blood volume （HBV）, mean transit time （MTT） of the contrast agent, capillary permeability-surface area product （PS）, hepatic arterial index （HAl）, hepatic artery perfusion （HAP）, and hepatic portal perfusion （HPP）. All these parameters reflected the perfusion status of liver parenchyma in normal rats. Three phases of enhancement were modified according to the time-density curves （TDCs） of the perfusion imaging： hepatic arterial phase （7 seconds）, hepatic portal venous phase （15 seconds）, and a delayed phase （23-31 seconds）. On examination by microscopy, the liver tissues were pathologically normal. Conclusions The appropriate protocol with multi-slice spiral CT liver perfusion reflected normal liver hemodynamics in rats. This study laid a solid foundation for further investigation of the physiological characteristics of liver cancer in a rat model, and was an important supplement to and reference for conventional contrast-enhanced CT scans.展开更多
基金supported in part by Science and Technology Program of Guangdong (No. 2018B030333001)the State’s Key Project of Research and Development Plan (Nos. 2017YFC0109202,2017YFA0104302 and 2017YFC0107900)the National Natural Science Foundation (Nos. 81530060 and 61871117)
文摘Cerebral perfusion computed tomography(PCT)is an important imaging modality for evaluating cerebrovascular diseases and stroke symptoms.With widespread public concern about the potential cancer risks and health hazards associated with cumulative radiation exposure in PCT imaging,considerable research has been conducted to reduce the radiation dose in X-ray-based brain perfusion imaging.Reducing the dose of X-rays causes severe noise and artifacts in PCT images.To solve this problem,we propose a deep learning method called NCS-Unet.The exceptional characteristics of non-subsampled contourlet transform(NSCT)and the Sobel filter are introduced into NCS-Unet.NSCT decomposes the convolved features into high-and low-frequency components.The decomposed high-frequency component retains image edges,contrast imaging traces,and noise,whereas the low-frequency component retains the main image information.The Sobel filter extracts the contours of the original image and the imaging traces caused by the contrast agent decay.The extracted information is added to NCS-Unet to improve its performance in noise reduction and artifact removal.Qualitative and quantitative analyses demonstrated that the proposed NCS-Unet can improve the quality of low-dose cone-beam CT perfusion reconstruction images and the accuracy of perfusion parameter calculations.
基金Supported by National Key R and D Program of China,No.2017YFC0107800CAMS Initiative for Innovative Medicine,No.2016-12M-2-004
文摘BACKGROUND Hepatopulmonary syndrome (HPS) is an arterial oxygenation defect induced by intrapulmonary vascular dilatation (IPVD) in the setting of liver disease and/or portal hypertension.This syndrome occurs most often in cirrhotic patients(4%-32%) and has been shown to be detrimental to functional status,quality of life,and survival.The diagnosis of HPS in the setting of liver disease and/or portal hypertension requires the demonstration of IPVD (i.e.,diffuse or localized abnormally dilated pulmonary capillaries and pulmonary and pleural arteriovenous communications) and arterial oxygenation defects,preferably by contrast-enhanced echocardiography and measurement of the alveolar-arterial oxygen gradient,respectively.AIM To compare brain and whole-body uptake of technetium for diagnosing HPS.METHODS Sixty-nine patients with chronic liver disease and/or portal hypertension were prospectively included.Brain uptake and whole-body uptake were calculated using the geometric mean of technetium counts in the brain and lungs and in the entire body and lungs,respectively.RESULTS Thirty-two (46%) patients had IPVD as detected by contrast-enhancedechocardiography.The demographics and clinical characteristics of the patients with and without IPVD were not significantly different with the exception of the creatinine level (0.71±0.18 mg/dL vs 0.83±0.23 mg/dL;P=0.041),alveolararterial oxygen gradient (23.2±13.3 mmHg vs 16.4±14.1 mmHg;P=0.043),and arterial partial pressure of oxygen (81.0±12.1 mmHg vs 90.1±12.8 mmHg;P=0.004).Whole-body uptake was significantly higher in patients with IPVD than in patients without IPVD (48.0%±6.1%vs 40.1%±8.1%;P=0.001).The area under the curve of whole-body uptake for detecting IPVD was significantly higher than that of brain uptake (0.75 vs 0.54;P=0.025).The optimal cut-off values of brain uptake and whole-body uptake for detecting IPVD were 5.7%and 42.5%,respectively,based on Youden’s index.The sensitivity,specificity,and accuracy of brain uptake> 5.7%and whole-body uptake> 42.5%for detecting IPVD were23%,89%,and 59%and 100%,52%,and 74%,respectively.CONCLUSION Whole-body uptake is superior to brain uptake for diagnosing HPS.
文摘AIM:To assess prospectively parameters of computed tomography perfusion(CT p) for evaluation of vascularity of liver metastases from neuroendocrine tumors.METHODS:This study was approved by the hospital's institutional review board.All 18 patients provided informed consent.There were 30 liver metastases from neuroendocrine tumors.Patients were divided into three groups depending on the appearance of the liver metastases at the arterial phase of morphological CT(hyperdense,hypodense and necrotic).Sequential acquisition of the liver was performed before and for 2 min after intravenous injection of 0.5 mg/kg contrast medium,at 4 mL/s.Data were analyzed using deconvolution analysis to calculate blood flow(BF),blood volume(BV),mean transit time(MTT),hepatic arterial perfusion index(HAPI) and a bi-compartmental analysis was performed to obtain vascular permeability-surface area product(PS).Post-treatment analysis was performed by a radiologist and regions of interest were plotted on the metastases,normal liver,aorta and portal vein.RESULTS:At the arterial phase of the morphological CT scan,the aspects of liver metastases were hyperdense(n=21),hypodense(n=7),and necrotic(n=2).In cases of necrotic metastases,none of the CT p parameters were changed.Compared to normal liver,a significant difference in all CT p parameters was found in cases of hyperdense metastases,and only for HAPI and MTT in cases of hypodense metastases.No significant difference was found for MTT and HAPI between hypo-and hyperdense metastases.A significant decrease of PS,BV and BF was demonstrated in cases of patients with hypodense lesions PS(23±11.6 mL/100 g per minute) compared to patients with hyperdense lesions;PS(13.5±10.4 mL/100 g per minute),BF(93.7±75.4 vs 196.0±115.6mL/100 g per minute) and BV(9.7±5.9 vs 24.5 10.9 mL/100 g).CONCLUSION:CT p provides additional information compared to the morphological appearance of liver metastases.
文摘Objective: To study the value of spiral CT perfusion parameters for evaluating acute pancreatitis and their correlation with inflammatory factor and JAK2/STAT3 signaling pathway. Methods: Patients with acute pancreatitis and patients with pancreatic trauma who underwent surgical resection in Liaocheng Dongchangfu People's Hospital between May 2014 and March 2017 were selected and enrolled in the AP group and the control group of the research respectively;spiral CT perfusion scanning was conducted before surgery to measure the blood flow (BF), blood volume (BV), and mean transit time (MTT), and the serum was collected to determine the contents of inflammatory factors;pancreatitis tissue and normal pancreatic tissue were collected after surgical resection to determine the expression of JAK2/STAT3 signal molecules. Results: pancreatic tissue BF and BV levels of AP group were significantly lower than those of control group while MTT level was not different from that of control group;CRP, PCT, HMGB-1, Ghrelin and sTREM-1 contents in serum as well as JAK2, STAT3, Bcl-2 and Bcl-xL mRNA expression in pancreatic tissue of AP group were significantly higher than those of control group and negatively correlated with BF and BV levels in pancreatic tissue. Conclusion: Spiral CT perfusion parameters BF and BV can reflect the microcirculatory disorder of acute pancreatitis and are associated with the increased secretion of inflammatory factors and the activation of JAK2/STAT3 signaling pathway in the course of disease.
文摘目的观察肝硬化(HC)合并原发性肝癌(PLC)患者CT动态增强扫描变化,分析其诊断价值。方法回顾性分析2020年4月—2022年7月我院125例HC患者资料,所有受试者均行病理组织学检测及CT动态增强扫描,统计所有患者病灶大小及分布情况,CT动态增强扫描动脉期、静脉期、延迟期病灶检出情况,以病理检查为金标准,分析CT动态增强扫描对HC患者PLC的诊断价值、HC患者与HC并PLC患者血流灌注参数大小及不同肝功能CTP分级下血流灌注参数变化。结果125例HC患者共检出161个病灶,其中直径<1 cm 8个,1~3 cm 53个,4~5 cm 63个,>5 cm 37个,肝右前叶、肝右后叶者居多,分别为45及69个;CT动态增强扫描动脉期检出病灶149个,检出率92.55%;门脉期检出病灶134个,检出率83.23%;延迟期检出病灶142个,检出率88.20%;125例HC患者中病理学检查显示75例PLC阳性,50例PLC阴性,CT动态增强扫检测HC并PLC的敏感度为94.67%,特异度为94.00%,准确率为94.40%,阳性预测值为95.95%,阴性预测值为92.16%,Kappa值为0.884,具有较高的一致性;HC组HAP、HPI值均显著低于HC并PLC组,PVP、TLP值均显著高于HC并PLC组(P<0.05);125例HC并PLC患者中CTP A级41例,CTP B级46例,CTP C级38例,CTP A级HAP、HPI值显著低于CTP B、C级(P<0.05),PVP、TLP值均显著高于CTP B、C级(P<0.05),CTP B级HPI值与CTP C级比较,差异均无统计学意义(P>0.05)。结论CT动态增强扫描可多方位多角度显示HC病灶情况,且对PLC具有较好的诊断价值,其中肝脏血流灌注参数具有一定的特征性,可为PLC诊断和肝功能分级提供参考。
文摘Background Multi-slice CT liver perfusion has been widely used in experimental studies of hemodynamic changes in liver lesions, and is usually performed as an adjunct to a conventional CT examination because of its high temporal and spatial resolution, simple protocol, good reproducibility, and ability to measure hemodynamic changes of liver tissues at the capillary level. Experimental rat models, especially those of induced liver cancer, are often used in studies of hemodynamic changes in liver cancer. Carcinogenesis in rats has a similar pathological progression and characteristics resembling those in human liver cancer; as a result, rat models are often used as ideal animal models in the study of human liver cancer. However, liver perfusion imaging in rats is difficult to perform, because rats＇ livers are so small that different concentrations, flow rates, and dose of contrast agents during the CT perfusion scanning can influence the quality of liver perfusion images in rats. The purpose of this study, therefore, was to investigate the optimal scan protocol for the imaging of hepatic perfusion using a deconvolution mathematical method in rats by comparing the results of rats in different injection conditions of the contrast agent, including concentration, rate and time. Methods Plain CT scan conditions in eighty 2-month-old male Wistar rats were 5.0 mm slice thickness, 5.0 mm interval, 1.0 pitch, 120 kV tube voltage, 60 mA tube current, 512x512 matrix, and FOV 9.6 cm. Perfusion scanning was carried out with different concentrations of diatrizoate （19%, 38%, 57%, and 76%）, different injection rates （0.3 and 0.5 ml/s）, and different injection times （1, 2-3, 4-5, and 6 seconds）. The above conditions were randomly matched and adjusted to determine the best perfusion scan protocol. Three-phase contrast-enhanced scanning was performed after CT perfusion. Histological examination of the liver tissues with hematoxylin and eosin stains was done after CT scanning. Results When the concentration of the contrast agent was 19% or 38%, no pseudo-color map was created. The viscosity increased when the concentration of the contrast agent was 76%; so it is difficult to inject the contrast agent at such a high concentration. Also no pseudo-color map was generated when the injection time was short （1, 2-3, and 4-5 seconds） or the injection rate was low （0.3 ml/s）. The best perfusion images and perfusion parameters were obtained during 50 seconds scanning. Each rat was given an injection of 57% diatrizoate at 0.5 mils via the tail vein using a high-pressure syringe for 6 seconds. The perfusion parameters included hepatic blood flow （HBF）, hepatic blood volume （HBV）, mean transit time （MTT） of the contrast agent, capillary permeability-surface area product （PS）, hepatic arterial index （HAl）, hepatic artery perfusion （HAP）, and hepatic portal perfusion （HPP）. All these parameters reflected the perfusion status of liver parenchyma in normal rats. Three phases of enhancement were modified according to the time-density curves （TDCs） of the perfusion imaging： hepatic arterial phase （7 seconds）, hepatic portal venous phase （15 seconds）, and a delayed phase （23-31 seconds）. On examination by microscopy, the liver tissues were pathologically normal. Conclusions The appropriate protocol with multi-slice spiral CT liver perfusion reflected normal liver hemodynamics in rats. This study laid a solid foundation for further investigation of the physiological characteristics of liver cancer in a rat model, and was an important supplement to and reference for conventional contrast-enhanced CT scans.
