Background Frequent premature ventricular complexes from the right ventricular outflow tract （RVOT-PVCs） are associated with left ventricular dysfunction.This study adopted two-dimensional speckle tracking imaging t...Background Frequent premature ventricular complexes from the right ventricular outflow tract （RVOT-PVCs） are associated with left ventricular dysfunction.This study adopted two-dimensional speckle tracking imaging to evaluate global and regional left ventricular myocardial function in patients with frequent RVOT-PVCs.Methods This study included 30 patients with frequent RVOT-PVCs and 30 healthy subjects.Aortic systolic velocity-time integral （AoVTI） and myocardium strain in circumferential （CS）,radial （RS） and longitudinal （LS） directions were evaluated by conventional echocardiography and speckle tracking imaging.All values of patients with RVOT-PVCs were recorded during sinus （PVC-S） and PVC beats （PVC-V）.Results Significant differences were demonstrated in global CS,RS and LS between the control subjects and the PVC-V （CS：（17.46±2.48）% vs.（11.52±3.28）%,RS：（48.26±10.20）% vs.（20.92±9.78）%,LS：（19.89±2.62）% vs.（11.79±3.66）%,P 〈0.01）,and in segmental RS and LS of nearly all the left ventricular segments.Statistical differences in segmental CS between the PVC-V and the control subjects were only observed in anterior,anteroseptal and septal segments （only seen in anteroseptal and septal segments at apex）.Furthermore,V/S AoVTI （AoVTI during the PVC beat divided by AoVTI during the sinus beat,then multiplied by 100%） correlated with coupling interval （r=0.67,P 〈0.001） and global strain （CS：r=0.48,P=0.007; RS：r=0.65,P 〈0.001; LS：r=0.65,P 〈0.001）.Conclusions Frequent RVOT-PVCs can induce global and regional left ventricular systolic dysfunction.The reduction of hemodynamic parameters relates to the coupling interval and the global systolic function.展开更多
Background Identifying the transmural extent of myocardial necrosis and the degree of myocardial viability in acute myocardial infarction （AMI） is important clinically. The aim of this study was to assess myocardial...Background Identifying the transmural extent of myocardial necrosis and the degree of myocardial viability in acute myocardial infarction （AMI） is important clinically. The aim of this study was to assess myocardial viability using two-dimensional speckle tracking imaging （2D-STI） in patients with AMI. Methods 2D-STI was performed at initial presentation, three days, and six months after primary percutaneous coronary intervention （PCI） in 30 patients with AMI, who had a left anterior descending coronary artery （LAD） culprit lesion. In addition, 20 patients who had minimal stenotic lesions （〈 30% stenosis） on coronary angiography were also included in the control group. At six months dobutamine echocardiography was performed for viability assessment in seven segments of the LAD territory. According to the recovery of wall motion abnormality, segments were classified as viable or non-viable. Results A total of 131 segments were viable, and 44 were nonviable. Multivariate analysis revealed significant differences between the viable and nonviable segments in the peak systolic strain, the peak systolic strain rate at initial presentation, and peak systolic strain rate three days after primary PCI. Among these, the initial peak systolic strain rate had the highest predictive value for myocardial viability （hazard ratio： 31.22, P 〈 0.01）. Conclusions 2D-STI is feasible for assessing myocardial viability, and the peak systolic strain rate might be the most reliable predictor of myocardial viability in patients with AMI.展开更多
The features of myocardial strains from speckle-tracking echocardiography (STE) have not been well defined in fulminant myocarditis (FM) patients.In this study,changes in the left ventricular ejection fraction (LVEF) ...The features of myocardial strains from speckle-tracking echocardiography (STE) have not been well defined in fulminant myocarditis (FM) patients.In this study,changes in the left ventricular ejection fraction (LVEF) and global and layer-specific myocardial strains over time were monitored.We aimed to determine the echocardiographic patterns of FM and ascertain their significance in FM treatment.Twenty patients who were clinically diagnosed with FM and received mechanical life support were prospectively enrolled.Conventional echocardiographic measurements were obtained,and serial strain echocardiography was performed from admission to hospital discharge until LVEF recovery (> 50%).Global/regional peak systolic longitudinal strains (GLS/RLS) and layer-specific longitudinal strains were quantified,and their changes with time were monitored in 14 FM patients.All patients had severely impaired cardiac function.Steep improvement in LVEF and GLS were observed within 6 days.Layer-specific strain analysis showed that reduction at admission or recovery at discharge in the endocardium and epicardium strains were equal.In conclusion,FM patients who received mechanical circulatory supports exhibited steep improvement in ventricular function within 6 days.The patchy and diffused distribution pattern of reduced RLS and equally and severely impaired strain in the endocardium and epicardium are valuable features in the diagnosis of FM.展开更多
This paper introduces some latest developments regarding the X-ray imaging methodology and applications of the X-ray imaging and biomedical application beamline(BL13W1)at Shanghai Synchrotron Radiation Facility in the...This paper introduces some latest developments regarding the X-ray imaging methodology and applications of the X-ray imaging and biomedical application beamline(BL13W1)at Shanghai Synchrotron Radiation Facility in the past 5 years.The photon energy range of the beamline is 8–72.5 keV.Several sets of X-ray imaging detectors with different pixel sizes(0.19–24 lm)are used to realize X-ray microcomputed tomography(X-ray micro-CT)and X-ray in-line phase-contrast imaging.To satisfy the requirements of user experiments,new X-ray imaging methods and image processing techniques are developed.In vivo dynamic micro-CT experiments with living insects are performed in 0.5 s(sampling rate of 2 Hz,2 tomograms/s)with a monochromatic beam from a wiggler source and in 40 ms(sampling rate of 25 Hz,25 tomograms/s)with a white beam from a bending magnet source.A new X-ray imaging method known as move contrast X-ray imaging is proposed,with which blood flow and moving tissues in raw images can be distinguished according to their moving frequencies in the time domain.Furthermore,X-ray speckle-tracking imaging with twice exposures to eliminate the edge enhancement effect is developed.A high-precision quantification method is realized to measure complex three-dimensional blood vessels obtained via X-ray micro-CT.X-ray imaging methods such as three-dimensional X-ray diffraction microscopy,small-angle X-ray scattering CT,and X-ray fluorescence CT are developed,in which the X-ray micro-CT imaging method is combined with other contrast mechanisms such as diffraction,scattering,and fluorescence contrasts respectively.Moreover,an X-ray nano-CT experiment is performed with a 100 nm spatial resolution.Typical user experimental results from the fields of material science,biomedicine,paleontology,physics,chemistry,and environmental science obtained on the beamline are provided.展开更多
文摘Background Frequent premature ventricular complexes from the right ventricular outflow tract （RVOT-PVCs） are associated with left ventricular dysfunction.This study adopted two-dimensional speckle tracking imaging to evaluate global and regional left ventricular myocardial function in patients with frequent RVOT-PVCs.Methods This study included 30 patients with frequent RVOT-PVCs and 30 healthy subjects.Aortic systolic velocity-time integral （AoVTI） and myocardium strain in circumferential （CS）,radial （RS） and longitudinal （LS） directions were evaluated by conventional echocardiography and speckle tracking imaging.All values of patients with RVOT-PVCs were recorded during sinus （PVC-S） and PVC beats （PVC-V）.Results Significant differences were demonstrated in global CS,RS and LS between the control subjects and the PVC-V （CS：（17.46±2.48）% vs.（11.52±3.28）%,RS：（48.26±10.20）% vs.（20.92±9.78）%,LS：（19.89±2.62）% vs.（11.79±3.66）%,P 〈0.01）,and in segmental RS and LS of nearly all the left ventricular segments.Statistical differences in segmental CS between the PVC-V and the control subjects were only observed in anterior,anteroseptal and septal segments （only seen in anteroseptal and septal segments at apex）.Furthermore,V/S AoVTI （AoVTI during the PVC beat divided by AoVTI during the sinus beat,then multiplied by 100%） correlated with coupling interval （r=0.67,P 〈0.001） and global strain （CS：r=0.48,P=0.007; RS：r=0.65,P 〈0.001; LS：r=0.65,P 〈0.001）.Conclusions Frequent RVOT-PVCs can induce global and regional left ventricular systolic dysfunction.The reduction of hemodynamic parameters relates to the coupling interval and the global systolic function.
文摘Background Identifying the transmural extent of myocardial necrosis and the degree of myocardial viability in acute myocardial infarction （AMI） is important clinically. The aim of this study was to assess myocardial viability using two-dimensional speckle tracking imaging （2D-STI） in patients with AMI. Methods 2D-STI was performed at initial presentation, three days, and six months after primary percutaneous coronary intervention （PCI） in 30 patients with AMI, who had a left anterior descending coronary artery （LAD） culprit lesion. In addition, 20 patients who had minimal stenotic lesions （〈 30% stenosis） on coronary angiography were also included in the control group. At six months dobutamine echocardiography was performed for viability assessment in seven segments of the LAD territory. According to the recovery of wall motion abnormality, segments were classified as viable or non-viable. Results A total of 131 segments were viable, and 44 were nonviable. Multivariate analysis revealed significant differences between the viable and nonviable segments in the peak systolic strain, the peak systolic strain rate at initial presentation, and peak systolic strain rate three days after primary PCI. Among these, the initial peak systolic strain rate had the highest predictive value for myocardial viability （hazard ratio： 31.22, P 〈 0.01）. Conclusions 2D-STI is feasible for assessing myocardial viability, and the peak systolic strain rate might be the most reliable predictor of myocardial viability in patients with AMI.
基金The project was supported by the grant from the National Natural Science Foundation of China(Nos.81873535 and 81570367)We thank Dr.Jonathan R.Linder who gave us helpful suggestions in writing the manuscript.
文摘The features of myocardial strains from speckle-tracking echocardiography (STE) have not been well defined in fulminant myocarditis (FM) patients.In this study,changes in the left ventricular ejection fraction (LVEF) and global and layer-specific myocardial strains over time were monitored.We aimed to determine the echocardiographic patterns of FM and ascertain their significance in FM treatment.Twenty patients who were clinically diagnosed with FM and received mechanical life support were prospectively enrolled.Conventional echocardiographic measurements were obtained,and serial strain echocardiography was performed from admission to hospital discharge until LVEF recovery (> 50%).Global/regional peak systolic longitudinal strains (GLS/RLS) and layer-specific longitudinal strains were quantified,and their changes with time were monitored in 14 FM patients.All patients had severely impaired cardiac function.Steep improvement in LVEF and GLS were observed within 6 days.Layer-specific strain analysis showed that reduction at admission or recovery at discharge in the endocardium and epicardium strains were equal.In conclusion,FM patients who received mechanical circulatory supports exhibited steep improvement in ventricular function within 6 days.The patchy and diffused distribution pattern of reduced RLS and equally and severely impaired strain in the endocardium and epicardium are valuable features in the diagnosis of FM.
基金This work was supported by the National Key Research and Development Program of China(Nos.2017YFA0403801,2016YFA0401302,2017YFA0206004,2018YFC1200204)the National Major Scientific Instruments and Equipment Development Project of China(No.11627901).
文摘This paper introduces some latest developments regarding the X-ray imaging methodology and applications of the X-ray imaging and biomedical application beamline(BL13W1)at Shanghai Synchrotron Radiation Facility in the past 5 years.The photon energy range of the beamline is 8–72.5 keV.Several sets of X-ray imaging detectors with different pixel sizes(0.19–24 lm)are used to realize X-ray microcomputed tomography(X-ray micro-CT)and X-ray in-line phase-contrast imaging.To satisfy the requirements of user experiments,new X-ray imaging methods and image processing techniques are developed.In vivo dynamic micro-CT experiments with living insects are performed in 0.5 s(sampling rate of 2 Hz,2 tomograms/s)with a monochromatic beam from a wiggler source and in 40 ms(sampling rate of 25 Hz,25 tomograms/s)with a white beam from a bending magnet source.A new X-ray imaging method known as move contrast X-ray imaging is proposed,with which blood flow and moving tissues in raw images can be distinguished according to their moving frequencies in the time domain.Furthermore,X-ray speckle-tracking imaging with twice exposures to eliminate the edge enhancement effect is developed.A high-precision quantification method is realized to measure complex three-dimensional blood vessels obtained via X-ray micro-CT.X-ray imaging methods such as three-dimensional X-ray diffraction microscopy,small-angle X-ray scattering CT,and X-ray fluorescence CT are developed,in which the X-ray micro-CT imaging method is combined with other contrast mechanisms such as diffraction,scattering,and fluorescence contrasts respectively.Moreover,an X-ray nano-CT experiment is performed with a 100 nm spatial resolution.Typical user experimental results from the fields of material science,biomedicine,paleontology,physics,chemistry,and environmental science obtained on the beamline are provided.
