Coronary artery disease is one of the most common and important health problems in the world. Early diagnosis of this disease is very important to treat before severe myocardial damage occurred. Myocardial perfusion s...Coronary artery disease is one of the most common and important health problems in the world. Early diagnosis of this disease is very important to treat before severe myocardial damage occurred. Myocardial perfusion scintigraphy (MPS) and computed tomography coronary angiography (CTCA) which evaluates regional myocardial perfusion and coronary arteries, respectively, are reliable and non-invasive methods in terms of coronary artery disease. In this study we aimed to compare MPS and CTCA based on conventional coronary angiography (CCA). Totally 60 patients were included in the study. CCA and MPS were performed to 30 patients;CCA and CTCA were performed to the rest of the patients (30 patients). Lesions were classified as mild, moderate and severe in these imaging methods. MPS and CTCA were compared with CCA by using chi-square and Fisher’s exact test. MPS and CTCA’s p values were found for left anterior descending artery (LAD) p: 0, p: 0.271;for circumflex artery (Cx) p: 0.256, p: 0.08 and for right coronary artery (RCA) p: 0.033, p: 0.271, respectively. Furthermore MPS and CTCA’s sensitivity, specificity, accuracy, positive predictive value and negative predictive value were calculated 81% to 87%;70% to 49%;73% to 72%;54% to 72%;90% to 71%, respectively. CCA results were found more concordant with MPS for LAD and RCA lesions and more concordant with CTCA for Cx lesions. It was also found that positive predictive value of MPS and negative predictive value of CTCA were significantly higher than the others. As a result, MPS and CTCA were suggested as complementary techniques for the diagnosis of coronary artery disease, not as alternatives to each other.展开更多
Movement of the patient during myocardial perfusion SPECT leads to some artifacts that make the interpretation difficult. In this study, myocardial perfusion imaging protocol was performed on a cardiac phantom and SPE...Movement of the patient during myocardial perfusion SPECT leads to some artifacts that make the interpretation difficult. In this study, myocardial perfusion imaging protocol was performed on a cardiac phantom and SPECT was performed by simulating patient movements. A lesion model with dimensions of 1.2 × 2 × 2 cm was created on the inferoseptal wall of the cardiac phantom. Imaging was done in circular orbits in 64 × 64 matrix and step and shoot mode. First set of images taken with no movement was referred as the reference image. During imaging, patient movement was simulated by moving the phantom in ±X and ±Y directions between the frames starting from 8th frame to 16th frame. At the end of imaging, Bull’s eye maps of images with movement were com-pared with Bull’s eye maps of reference images. Bull’s eye maps were evaluated by an experienced nuclear medicine physician. Shifting patient’s movement in all directions by ±1 and ±2 cm, dis-placed the localization of the lesion mildly and this did not hamper the evaluation. However, movements of ±3 or ±4 cm resulted in artifacts which in turn caused partial or no visualization of the lesion. In motion corrected images, the lesion could be evaluated in ±1 and ±2 cm movements while lesion could not be evaluated in ±3 and ±4 cm movements. As a result, movement greater than ±3 cm causes significant image artifacts and this should be considered as a potential source of error in myocardial perfusion studies.展开更多
Introduction: During the pharmacological stress test with dipyridamole, a normal hemodynamic response is slightly reduced blood pressure and raised heart rate (HR). However, sometimes the HR response is reduced. This ...Introduction: During the pharmacological stress test with dipyridamole, a normal hemodynamic response is slightly reduced blood pressure and raised heart rate (HR). However, sometimes the HR response is reduced. This study investigated the relationship between the HR response during the dipyridamole stress test and the severity of the perfusion defects using Thallium 201 myocardial perfusion imaging. Methods: We enrolled 50 patients undergoing dipyridamole stress at the nuclear cardiology Lab, Main University Hospital of Alexandria. Standard dipyridamole protocol (infusion over 4 min) and standard thallium 201 protocol (2 min after dipyridamole infusion) were followed. If the heart rate (HR) ratio (peak HR/rest HR) was 1.20 or less, it was considered a reduced response. Total perfusion defect (TPD), summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) for myocardial perfusion<span style="white-space:normal;font-family:;" "=""> </span><span style="white-space:normal;font-family:;" "="">were calculated. Patients with reduced HR response and normal HR responses were compared and independent predictors of reduced HR response were determined. Results: About 56% of patients had reduced HR response;which included a high number of patients with a history of dyslipidemia and diabetes mellitus. The reduced HR response group showed lower SSS, SRS. The analysis showed that the independent predictors of reduced HR response were rest HR, SSS, and diabetes mellitus. Conclusions: Reduction in the HR response during the dipyridamole-induced stress test is related to the severity of perfusion defect, diabetes mellitus, and Dyslipidemia.</span>展开更多
Background High-frequency oscillatory ventilation （HFOV） allows for small tidal volumes at mean airway pressures （mPaw） above that of conventional mechanical ventilation （CMV）,but the effect of HFOV on hemodynam...Background High-frequency oscillatory ventilation （HFOV） allows for small tidal volumes at mean airway pressures （mPaw） above that of conventional mechanical ventilation （CMV）,but the effect of HFOV on hemodynamics,oxygen metabolism,and tissue perfusion in acute respiratory distress syndrome （ARDS） remains unclear.We investigated the effects of HFOV and CMV in sheep models with ARDS.Methods After inducing ARDS by repeated lavage,twelve adult sheep were randomly divided into a HFOV or CMV group.After stabilization,standard lung recruitments （40 cmH2O × 40 seconds） were performed.The optimal mPaw or positive end-expiratory pressure was obtained by lung recruitment and decremental positive end-expiratory pressure titration.The animals were then ventilated for 4 hours.The hemodynamics,tissue perfusion （superior mesenteric artery blood flow,pHi,and Pg-aCO2）,oxygen metabolism and respiratory mechanics were examined at baseline before saline lavage,in the ARDS model,after model stabilization,and during hourly mechanical ventilation for up to 4 hours.A two-way repeated measures analysis of variance was applied to evaluate differences between the groups.Results The titrated mPaw was higher and the tidal volumes lower in the HFOV group than the positive end-expiratory pressure in the CMV group.There was no significant difference in hemodynamic parameters between the HFOV and CMV groups.There was no difference in the mean alveolar pressure between the two groups.After lung recruitment,both groups showed an improvement in the oxygenation,oxygen delivery,and DO2.Lactate levels increased in both groups after inducing the ARDS model.Compared with the CMV group,the superior mesenteric artery blood flow and pHi were significantly higher in the HFOV group,but the Pg-aCO2 decreased in the HFOV group.Conclusion Compared with CMV,HFOV with optimal mPaw has no significant side effect on hemodynamics or oxygen metabolism,and increases gastric tissue blood perfusion.展开更多
Background The assessment of regional pulmonary ventilation and perfusion is essential for the evaluation of a variety of lung disorders. Pulmonary ventilation MRI using inhaled oxygen as a contrast medium can be obt...Background The assessment of regional pulmonary ventilation and perfusion is essential for the evaluation of a variety of lung disorders. Pulmonary ventilation MRI using inhaled oxygen as a contrast medium can be obtained with a clinical MR scanner, without additional equipment, and has been demonstrated to be a feasible means of assessing ventilation in animal models and some clinical patients. However, few studies have reported on MR ventilation-perfusion imaging. In this study, we evaluated the usefulness of oxygen-enhanced ventilation in combination with first-pass Gd-DTPA-enhanced perfusion MRI in a canine model of pulmonary embolism and airway obstruction.Methods Peripheral pulmonary embolisms were produced in eight dogs by intravenous injection of gelfoam strips at the pulmonary segmental arterial level, and airway obstructions were created in five of the dogs by inserting a self-designed balloon catheter into a secondary bronchus. Oxygen-enhanced MR ventilation images were produced by subtracting images from before and after inhalation of pure oxygen. Pulmonary perfusion MR images were acquired with a dynamic three-dimensional fast gradient-echo sequence. MR ventilation and perfusion images were read and contrasted with results from general examinations of pathological anatomy, ventilation-perfusion scintigraphy, and pulmonary angiography. Results Regions identified as having airway obstructions matched using both MR ventilation and perfusion imaging, but regions of pulmonary embolisms were mismatched. The area of airway obstruction defects was smaller using MR ventilation imagery than that using ventilation scintigraphy. Abnormal perfusion regions due to pulmonary embolisms were divided into defective regions and reduced regions based on the time course of signal intensity changes. In the diagnosis of pulmonary embolisms with the technique of ventilation and perfusion MRI, sensitivity and specificity were 75.0% and 98.1%, respectively, and the diagnostic results of this MRI technique were in agreement with the results of ventilation-perfusion scintigraphy and pulmonary angiography (K: 0.899, 0.743).Conclusions Oxygen-enhanced ventilation in combination with pulmonary perfusion MRI can be used to diagnose abnormalities of airways and blood vessels in the lungs, and can provide regional functional information with high spatial and temporal resolution. This method possesses great potential value for clinical applications. F展开更多
BACKGROUND The prevalence of type 2 diabetes(T2D)has been increasing dramatically in recent decades,and 47.5%of T2D patients will die of cardiovascular disease.Thallium-201 myocardial perfusion scan(MPS)is a precise a...BACKGROUND The prevalence of type 2 diabetes(T2D)has been increasing dramatically in recent decades,and 47.5%of T2D patients will die of cardiovascular disease.Thallium-201 myocardial perfusion scan(MPS)is a precise and noninvasive method to detect coronary artery disease(CAD).Most previous studies used traditional logistic regression(LGR)to evaluate the risks for abnormal CAD.Rapidly developing machine learning(Mach-L)techniques could potentially outperform LGR in capturing non-linear relationships.AIM To aims were:(1)Compare the accuracy of Mach-L methods and LGR;and(2)Found the most important factors for abnormal TMPS.METHODS 556 T2D were enrolled in the study(287 men and 269 women).Demographic and biochemistry data were used as independent variables and the sum of stressed score derived from MPS scan was the dependent variable.Subjects with a MPS score≥9 were defined as abnormal.In addition to traditional LGR,classification and regression tree(CART),random forest,Naïve Bayes,and eXtreme gradient boosting were also applied.Sensitivity,specificity,accuracy and area under the receiver operation curve were used to evaluate the respective accuracy of LGR and Mach-L methods.RESULTS Except for CART,the other Mach-L methods outperformed LGR,with gender,body mass index,age,low-density lipoprotein cholesterol,glycated hemoglobin and smoking emerging as the most important factors to predict abnormal MPS.CONCLUSION Four Mach-L methods are found to outperform LGR in predicting abnormal TMPS in Chinese T2D,with the most important risk factors being gender,body mass index,age,low-density lipoprotein cholesterol,glycated hemoglobin and smoking.展开更多
目的:探讨不同呼气末正压通气(Positive end expiratory pressure,PEEP)水平对慢性阻塞性肺疾病急性加重期(Acute exacerbation of chronic obstructive pulmonary disease,AECOPD)伴肺动脉高压患者的影响。方法:选取2020年6月至2022年...目的:探讨不同呼气末正压通气(Positive end expiratory pressure,PEEP)水平对慢性阻塞性肺疾病急性加重期(Acute exacerbation of chronic obstructive pulmonary disease,AECOPD)伴肺动脉高压患者的影响。方法:选取2020年6月至2022年5月期间我院收治的103例AECOPD伴肺动脉高压患者作为研究对象,所有患者按照随机数字表法分为常规组(n=51)和高水平组(n=52)。常规组采用常规PEEP,高水平组采用高水平PEEP,两组患者均持续治疗3 d。观察两组氧利用率、血清炎性因子、脑血流灌注以及肺功能。结果:治疗3 d后,高水平组氧利用率(Ratio of oxygen utilization,O_(2)UC)高于常规组(P<0.05);高水平组超敏C-反应蛋白(High sensitivity C-reactive protein,hs-CRP)、肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)、白-细胞介素-6(Interleukin-6,IL-6)以及降钙素原(Procalcitonin,PCT)水平低于常规组(P<0.05);高水平组阻力指数(Resistance Index,RI)、搏动指数(Pulsatility index,PI)和平均血流速度(Mean velocity,Vm)和常规组无明显差异(P>0.05);高水平组肺用力肺活量占预计值百分比(Percentage of forced vital capacity to the expected value,FVC%pred)、第一秒用力呼气容积占预计值百分比(Percentage of forced expiratory volume in the first second to the expected value,FEV1%pred)、第一秒用力呼气容积占用力肺活量百分比(Percentage of forced expiratory volume in the first second to forced vital capacity,FEV1/FVC)均高于常规组(P<0.05)。结论:相比较于常规PEEP,将高水平PEEP用于AECOPD伴肺动脉高压患者中可提高氧利用率,促进肺功能恢复,减轻机体炎症反应,且不影响脑血流灌注。展开更多
文摘Coronary artery disease is one of the most common and important health problems in the world. Early diagnosis of this disease is very important to treat before severe myocardial damage occurred. Myocardial perfusion scintigraphy (MPS) and computed tomography coronary angiography (CTCA) which evaluates regional myocardial perfusion and coronary arteries, respectively, are reliable and non-invasive methods in terms of coronary artery disease. In this study we aimed to compare MPS and CTCA based on conventional coronary angiography (CCA). Totally 60 patients were included in the study. CCA and MPS were performed to 30 patients;CCA and CTCA were performed to the rest of the patients (30 patients). Lesions were classified as mild, moderate and severe in these imaging methods. MPS and CTCA were compared with CCA by using chi-square and Fisher’s exact test. MPS and CTCA’s p values were found for left anterior descending artery (LAD) p: 0, p: 0.271;for circumflex artery (Cx) p: 0.256, p: 0.08 and for right coronary artery (RCA) p: 0.033, p: 0.271, respectively. Furthermore MPS and CTCA’s sensitivity, specificity, accuracy, positive predictive value and negative predictive value were calculated 81% to 87%;70% to 49%;73% to 72%;54% to 72%;90% to 71%, respectively. CCA results were found more concordant with MPS for LAD and RCA lesions and more concordant with CTCA for Cx lesions. It was also found that positive predictive value of MPS and negative predictive value of CTCA were significantly higher than the others. As a result, MPS and CTCA were suggested as complementary techniques for the diagnosis of coronary artery disease, not as alternatives to each other.
文摘Movement of the patient during myocardial perfusion SPECT leads to some artifacts that make the interpretation difficult. In this study, myocardial perfusion imaging protocol was performed on a cardiac phantom and SPECT was performed by simulating patient movements. A lesion model with dimensions of 1.2 × 2 × 2 cm was created on the inferoseptal wall of the cardiac phantom. Imaging was done in circular orbits in 64 × 64 matrix and step and shoot mode. First set of images taken with no movement was referred as the reference image. During imaging, patient movement was simulated by moving the phantom in ±X and ±Y directions between the frames starting from 8th frame to 16th frame. At the end of imaging, Bull’s eye maps of images with movement were com-pared with Bull’s eye maps of reference images. Bull’s eye maps were evaluated by an experienced nuclear medicine physician. Shifting patient’s movement in all directions by ±1 and ±2 cm, dis-placed the localization of the lesion mildly and this did not hamper the evaluation. However, movements of ±3 or ±4 cm resulted in artifacts which in turn caused partial or no visualization of the lesion. In motion corrected images, the lesion could be evaluated in ±1 and ±2 cm movements while lesion could not be evaluated in ±3 and ±4 cm movements. As a result, movement greater than ±3 cm causes significant image artifacts and this should be considered as a potential source of error in myocardial perfusion studies.
文摘Introduction: During the pharmacological stress test with dipyridamole, a normal hemodynamic response is slightly reduced blood pressure and raised heart rate (HR). However, sometimes the HR response is reduced. This study investigated the relationship between the HR response during the dipyridamole stress test and the severity of the perfusion defects using Thallium 201 myocardial perfusion imaging. Methods: We enrolled 50 patients undergoing dipyridamole stress at the nuclear cardiology Lab, Main University Hospital of Alexandria. Standard dipyridamole protocol (infusion over 4 min) and standard thallium 201 protocol (2 min after dipyridamole infusion) were followed. If the heart rate (HR) ratio (peak HR/rest HR) was 1.20 or less, it was considered a reduced response. Total perfusion defect (TPD), summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) for myocardial perfusion<span style="white-space:normal;font-family:;" "=""> </span><span style="white-space:normal;font-family:;" "="">were calculated. Patients with reduced HR response and normal HR responses were compared and independent predictors of reduced HR response were determined. Results: About 56% of patients had reduced HR response;which included a high number of patients with a history of dyslipidemia and diabetes mellitus. The reduced HR response group showed lower SSS, SRS. The analysis showed that the independent predictors of reduced HR response were rest HR, SSS, and diabetes mellitus. Conclusions: Reduction in the HR response during the dipyridamole-induced stress test is related to the severity of perfusion defect, diabetes mellitus, and Dyslipidemia.</span>
基金This study was supported by the grants from the National Natural Science Foundation of China （No. 81372093 and No. 81370180）, the Foundation of Jiangsu Province Department of Health （No. H201432） and the Special Fund for Health-Scientific Research in the Public Interest Program from Ministry of Health, China （No. 20120201 !）.
文摘Background High-frequency oscillatory ventilation （HFOV） allows for small tidal volumes at mean airway pressures （mPaw） above that of conventional mechanical ventilation （CMV）,but the effect of HFOV on hemodynamics,oxygen metabolism,and tissue perfusion in acute respiratory distress syndrome （ARDS） remains unclear.We investigated the effects of HFOV and CMV in sheep models with ARDS.Methods After inducing ARDS by repeated lavage,twelve adult sheep were randomly divided into a HFOV or CMV group.After stabilization,standard lung recruitments （40 cmH2O × 40 seconds） were performed.The optimal mPaw or positive end-expiratory pressure was obtained by lung recruitment and decremental positive end-expiratory pressure titration.The animals were then ventilated for 4 hours.The hemodynamics,tissue perfusion （superior mesenteric artery blood flow,pHi,and Pg-aCO2）,oxygen metabolism and respiratory mechanics were examined at baseline before saline lavage,in the ARDS model,after model stabilization,and during hourly mechanical ventilation for up to 4 hours.A two-way repeated measures analysis of variance was applied to evaluate differences between the groups.Results The titrated mPaw was higher and the tidal volumes lower in the HFOV group than the positive end-expiratory pressure in the CMV group.There was no significant difference in hemodynamic parameters between the HFOV and CMV groups.There was no difference in the mean alveolar pressure between the two groups.After lung recruitment,both groups showed an improvement in the oxygenation,oxygen delivery,and DO2.Lactate levels increased in both groups after inducing the ARDS model.Compared with the CMV group,the superior mesenteric artery blood flow and pHi were significantly higher in the HFOV group,but the Pg-aCO2 decreased in the HFOV group.Conclusion Compared with CMV,HFOV with optimal mPaw has no significant side effect on hemodynamics or oxygen metabolism,and increases gastric tissue blood perfusion.
基金ThisworkwassupportedbytheNationalNaturalScienceFoundationofChina (No 3 0 2 0 0 0 66)andtheKeyClinicalSubjectFoundationoftheMinistryofHealthofChina (No .2 0 0 12 0 2 8)
文摘Background The assessment of regional pulmonary ventilation and perfusion is essential for the evaluation of a variety of lung disorders. Pulmonary ventilation MRI using inhaled oxygen as a contrast medium can be obtained with a clinical MR scanner, without additional equipment, and has been demonstrated to be a feasible means of assessing ventilation in animal models and some clinical patients. However, few studies have reported on MR ventilation-perfusion imaging. In this study, we evaluated the usefulness of oxygen-enhanced ventilation in combination with first-pass Gd-DTPA-enhanced perfusion MRI in a canine model of pulmonary embolism and airway obstruction.Methods Peripheral pulmonary embolisms were produced in eight dogs by intravenous injection of gelfoam strips at the pulmonary segmental arterial level, and airway obstructions were created in five of the dogs by inserting a self-designed balloon catheter into a secondary bronchus. Oxygen-enhanced MR ventilation images were produced by subtracting images from before and after inhalation of pure oxygen. Pulmonary perfusion MR images were acquired with a dynamic three-dimensional fast gradient-echo sequence. MR ventilation and perfusion images were read and contrasted with results from general examinations of pathological anatomy, ventilation-perfusion scintigraphy, and pulmonary angiography. Results Regions identified as having airway obstructions matched using both MR ventilation and perfusion imaging, but regions of pulmonary embolisms were mismatched. The area of airway obstruction defects was smaller using MR ventilation imagery than that using ventilation scintigraphy. Abnormal perfusion regions due to pulmonary embolisms were divided into defective regions and reduced regions based on the time course of signal intensity changes. In the diagnosis of pulmonary embolisms with the technique of ventilation and perfusion MRI, sensitivity and specificity were 75.0% and 98.1%, respectively, and the diagnostic results of this MRI technique were in agreement with the results of ventilation-perfusion scintigraphy and pulmonary angiography (K: 0.899, 0.743).Conclusions Oxygen-enhanced ventilation in combination with pulmonary perfusion MRI can be used to diagnose abnormalities of airways and blood vessels in the lungs, and can provide regional functional information with high spatial and temporal resolution. This method possesses great potential value for clinical applications. F
基金The study was reviewed and approved by the Cardinal Tien Hospital Institutional Review Board(Approval No.CTH-102-2-5-024).
文摘BACKGROUND The prevalence of type 2 diabetes(T2D)has been increasing dramatically in recent decades,and 47.5%of T2D patients will die of cardiovascular disease.Thallium-201 myocardial perfusion scan(MPS)is a precise and noninvasive method to detect coronary artery disease(CAD).Most previous studies used traditional logistic regression(LGR)to evaluate the risks for abnormal CAD.Rapidly developing machine learning(Mach-L)techniques could potentially outperform LGR in capturing non-linear relationships.AIM To aims were:(1)Compare the accuracy of Mach-L methods and LGR;and(2)Found the most important factors for abnormal TMPS.METHODS 556 T2D were enrolled in the study(287 men and 269 women).Demographic and biochemistry data were used as independent variables and the sum of stressed score derived from MPS scan was the dependent variable.Subjects with a MPS score≥9 were defined as abnormal.In addition to traditional LGR,classification and regression tree(CART),random forest,Naïve Bayes,and eXtreme gradient boosting were also applied.Sensitivity,specificity,accuracy and area under the receiver operation curve were used to evaluate the respective accuracy of LGR and Mach-L methods.RESULTS Except for CART,the other Mach-L methods outperformed LGR,with gender,body mass index,age,low-density lipoprotein cholesterol,glycated hemoglobin and smoking emerging as the most important factors to predict abnormal MPS.CONCLUSION Four Mach-L methods are found to outperform LGR in predicting abnormal TMPS in Chinese T2D,with the most important risk factors being gender,body mass index,age,low-density lipoprotein cholesterol,glycated hemoglobin and smoking.
文摘目的:探讨不同呼气末正压通气(Positive end expiratory pressure,PEEP)水平对慢性阻塞性肺疾病急性加重期(Acute exacerbation of chronic obstructive pulmonary disease,AECOPD)伴肺动脉高压患者的影响。方法:选取2020年6月至2022年5月期间我院收治的103例AECOPD伴肺动脉高压患者作为研究对象,所有患者按照随机数字表法分为常规组(n=51)和高水平组(n=52)。常规组采用常规PEEP,高水平组采用高水平PEEP,两组患者均持续治疗3 d。观察两组氧利用率、血清炎性因子、脑血流灌注以及肺功能。结果:治疗3 d后,高水平组氧利用率(Ratio of oxygen utilization,O_(2)UC)高于常规组(P<0.05);高水平组超敏C-反应蛋白(High sensitivity C-reactive protein,hs-CRP)、肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)、白-细胞介素-6(Interleukin-6,IL-6)以及降钙素原(Procalcitonin,PCT)水平低于常规组(P<0.05);高水平组阻力指数(Resistance Index,RI)、搏动指数(Pulsatility index,PI)和平均血流速度(Mean velocity,Vm)和常规组无明显差异(P>0.05);高水平组肺用力肺活量占预计值百分比(Percentage of forced vital capacity to the expected value,FVC%pred)、第一秒用力呼气容积占预计值百分比(Percentage of forced expiratory volume in the first second to the expected value,FEV1%pred)、第一秒用力呼气容积占用力肺活量百分比(Percentage of forced expiratory volume in the first second to forced vital capacity,FEV1/FVC)均高于常规组(P<0.05)。结论:相比较于常规PEEP,将高水平PEEP用于AECOPD伴肺动脉高压患者中可提高氧利用率,促进肺功能恢复,减轻机体炎症反应,且不影响脑血流灌注。
