We studied the wall motion characteristics of the ascending aorta by velocity vector imaging （VVI） in primary hypertension patients. The ascending aortas both in 30 patients with primary hypertension and 30 normal c...We studied the wall motion characteristics of the ascending aorta by velocity vector imaging （VVI） in primary hypertension patients. The ascending aortas both in 30 patients with primary hypertension and 30 normal controls were examined by Acuson sequoia 512 equiped with VVI. The maximum velocity （Vs, Ve） of every point on the anterior wall of ascending aorta both in systole and diastole was measured. The aortic diameter was wider in the hypertension patients than that in the healthy subjects （P〈0.05）. The movement amplitude of the anterior wall of the ascending aorta in long axis view in the hypertension patients was lower than that in the healthy subjects （P〈0.05）. The motion and time to peak in systole of each point of the ascending aorta in the healthy subjects had no significant difference （P〉0.05）. The velocity curves of the anterior wall of ascending aorta both in the hypertension and healthy subjects were regular, and the curve in systole was named S wave and that in diastole named E wave. The velocity of S wave and E wave was slower in the hypertension patients than that in the healthy subjects （P〈0.05）. The time to peak of S wave on the anterior wall of ascending aorta in systole was shorter in the hypertension patients than in the healthy subjects （P〈0.05）. VVI could be used to accurately and directly observe the movement character of the ascending aorta walls, which would help us understand the elasticity of great arteries in patients with hypertension.展开更多
Background Tagged magnetic resonance imaging （MRI） is the non-invasive golden standard to measure myocardial deformity. Tissue Doppler Imaging can be used to assess myocardial deformity, however, it has the limitati...Background Tagged magnetic resonance imaging （MRI） is the non-invasive golden standard to measure myocardial deformity. Tissue Doppler Imaging can be used to assess myocardial deformity, however, it has the limitation of angle-dependence. Our study aimed to compare left ventricular torsion and strains measured by velocity-vector imaging （Wl） using echocardiography （echo-Wl） and MRI （MRI-WI）, and to validate them against harmonic phase tagged MRI （HARP MRI）. Methods A total number of 34 subjects （14 normal and 20 patients） were evaluated. Apical and basal image of left ventdcular short axis view were acquired for measurements of apical and basal rotation, circumferential and radial strain using both echo-VVI and MRI-WI. An apical four-chamber view was obtained for measuring the distance between the apical and basal levels. Results The correlations of segmental rotations, circumferential and radial strains were high between echo-WI and HARP MRI, while the agreement of apical rotation was poor. Left ventricular torsion showed much better correlation and agreement between echo-WI and HARP MRI than apical rotation： the coefficient was 0.97, P 〈0.001. The correlation between MRI-WI and HARP MRI in quantifying rotational parameters and strains was similar with echo-Wl and HARP MRI. Echo-WI could discriminate normal and dysfunctional ventricles on either hypertensive or dilated cardiomyopathy. Conclusion The data from this study show that （1） it is feasible to quantify left ventricular torsion and myocardial strain using echo-WI and MRI-WI in normal subjects, patients with left ventricular global systolic dysfunction and segment systolic dysfunction; （2） the agreement among all mechanical parameters derived from echo-Wl, MRI-WI, and HARP MRI remained with clinically acceptable ran qes.展开更多
Background Pulmonary hypertension （PH） is a set of pathophysiological syndromes characterized by increased pulmonary artery pressure and pulmonary vascular resistance,resulting in increased right ventricular afterlo...Background Pulmonary hypertension （PH） is a set of pathophysiological syndromes characterized by increased pulmonary artery pressure and pulmonary vascular resistance,resulting in increased right ventricular afterload.The left and right ventricles interact through hemodynamics.What impact will PH have on synchronization and function of the left ventricle （LV）？ The aim of this study was to evaluate the synchronization of the left ventricular wall motion and left ventricular function in patients with varying degrees of PH using velocity vector imaging （Wl） technology.Methods Sixty patients with chronic PH served as the experimental group,and 20 healthy volunteers served as the control group.According to the different degrees of pulmonary artery systolic pressure,the experimental group was divided into three groups：mild,moderate,and severe PH groups.The time to peak systolic longitudinal velocity （Tvl）,the peak systolic longitudinal velocity （Vsl）,the peak diastolic longitudinal velocity （Vel）,the peak systolic longitudinal strain （SI）,and strain rate （SRI） in 18 segments were measured in each group.Results TvI in the control group and each group with PH was reduced from basal to apical segment,and in control group Tvl in various segments of the same wall and in different walls showed no significant difference （P ＞0.05）.With increase in pulmonary artery pressure,Tvl values measured showed an increasing trend in groups with PH.In groups with PH,Vsl and Vel of each wall were reduced sequentially from basal to apical segments,showing gradient change; Vsl and Vel values measured showed a decreasing trend with increase in pulmonary artery pressure,in which the differences of Vel values measured in the control group and the mild PH group were statistically significant （P ＜0.01）,and the differences between other groups were statistically significant （P ＜0.01）.In groups with PH,SI and SRI in basal segment and the middle segment of each wall were decreased; the difference between groups was statistically significant （P ＜0.01）.Conclusions Asynchronization of the LV and decreased left ventricular function were present in patients with chronic PH;WI technology can accurately evaluate left ventricular function in patients with PH,and indicators such as Tvl,Vsl,and Vel are valuable.展开更多
Background The velocity vector imaging is an ultrasound speckle imaging that was recently developed, which is based on the two-dimensional gray scale image, with more accurate tracking process and more conve-nient and...Background The velocity vector imaging is an ultrasound speckle imaging that was recently developed, which is based on the two-dimensional gray scale image, with more accurate tracking process and more conve-nient and time-saving operation method can quantitatively displays the varied curve of myocardial velocity and direction sampling taking from multiple parts in one cardiac cycle by tracking the space motion of echo spots of the cardiovascular tissue, and then analyze their movements, avoiding the angular dependence and the limita-tions of analysis section that could effect on Doppler technology. The technology provides a new auxiliary method for the diagnosis and treatment of cardiovascular disease and is valuable on clinical diagnosis and scientific re-search and a wide horizon of development.展开更多
Side-looking SAR raw data can be obtained from the commercial market. Comparatively, in other modes such as squint SAR and spotlight SAR and the real flight echo data are hardly acquired. A new approach called the int...Side-looking SAR raw data can be obtained from the commercial market. Comparatively, in other modes such as squint SAR and spotlight SAR and the real flight echo data are hardly acquired. A new approach called the integrated velocity transformation is presented in this paper, which can approximately transform the side-looking raw data to a squint mode. The simulation proves the method is acceptable.展开更多
INTRODUCTIONlschemic stroke accounts for 70% of all the cerebrovascular diseases. Severe stenosis and occlusions ofextracranial and intracranial artery are all important risk factors causing ischemic stroke. Based on ...INTRODUCTIONlschemic stroke accounts for 70% of all the cerebrovascular diseases. Severe stenosis and occlusions ofextracranial and intracranial artery are all important risk factors causing ischemic stroke. Based on the widespread observation worldwide, intracranial atherosclerosis is the most common vascular lesions in Asians, Hispanics, and Africans. Therefore, accurate and noninvasive methods fbr early diagnosis of stroke in individuals without significant stenosis of the extracranial carotid artery is of considerable clinical interest.展开更多
文摘We studied the wall motion characteristics of the ascending aorta by velocity vector imaging （VVI） in primary hypertension patients. The ascending aortas both in 30 patients with primary hypertension and 30 normal controls were examined by Acuson sequoia 512 equiped with VVI. The maximum velocity （Vs, Ve） of every point on the anterior wall of ascending aorta both in systole and diastole was measured. The aortic diameter was wider in the hypertension patients than that in the healthy subjects （P〈0.05）. The movement amplitude of the anterior wall of the ascending aorta in long axis view in the hypertension patients was lower than that in the healthy subjects （P〈0.05）. The motion and time to peak in systole of each point of the ascending aorta in the healthy subjects had no significant difference （P〉0.05）. The velocity curves of the anterior wall of ascending aorta both in the hypertension and healthy subjects were regular, and the curve in systole was named S wave and that in diastole named E wave. The velocity of S wave and E wave was slower in the hypertension patients than that in the healthy subjects （P〈0.05）. The time to peak of S wave on the anterior wall of ascending aorta in systole was shorter in the hypertension patients than in the healthy subjects （P〈0.05）. VVI could be used to accurately and directly observe the movement character of the ascending aorta walls, which would help us understand the elasticity of great arteries in patients with hypertension.
文摘Background Tagged magnetic resonance imaging （MRI） is the non-invasive golden standard to measure myocardial deformity. Tissue Doppler Imaging can be used to assess myocardial deformity, however, it has the limitation of angle-dependence. Our study aimed to compare left ventricular torsion and strains measured by velocity-vector imaging （Wl） using echocardiography （echo-Wl） and MRI （MRI-WI）, and to validate them against harmonic phase tagged MRI （HARP MRI）. Methods A total number of 34 subjects （14 normal and 20 patients） were evaluated. Apical and basal image of left ventdcular short axis view were acquired for measurements of apical and basal rotation, circumferential and radial strain using both echo-VVI and MRI-WI. An apical four-chamber view was obtained for measuring the distance between the apical and basal levels. Results The correlations of segmental rotations, circumferential and radial strains were high between echo-WI and HARP MRI, while the agreement of apical rotation was poor. Left ventricular torsion showed much better correlation and agreement between echo-WI and HARP MRI than apical rotation： the coefficient was 0.97, P 〈0.001. The correlation between MRI-WI and HARP MRI in quantifying rotational parameters and strains was similar with echo-Wl and HARP MRI. Echo-WI could discriminate normal and dysfunctional ventricles on either hypertensive or dilated cardiomyopathy. Conclusion The data from this study show that （1） it is feasible to quantify left ventricular torsion and myocardial strain using echo-WI and MRI-WI in normal subjects, patients with left ventricular global systolic dysfunction and segment systolic dysfunction; （2） the agreement among all mechanical parameters derived from echo-Wl, MRI-WI, and HARP MRI remained with clinically acceptable ran qes.
基金This work is supported by a grant from the Natural Science Foundation of Hebei Province （No. 2010000550）.
文摘Background Pulmonary hypertension （PH） is a set of pathophysiological syndromes characterized by increased pulmonary artery pressure and pulmonary vascular resistance,resulting in increased right ventricular afterload.The left and right ventricles interact through hemodynamics.What impact will PH have on synchronization and function of the left ventricle （LV）？ The aim of this study was to evaluate the synchronization of the left ventricular wall motion and left ventricular function in patients with varying degrees of PH using velocity vector imaging （Wl） technology.Methods Sixty patients with chronic PH served as the experimental group,and 20 healthy volunteers served as the control group.According to the different degrees of pulmonary artery systolic pressure,the experimental group was divided into three groups：mild,moderate,and severe PH groups.The time to peak systolic longitudinal velocity （Tvl）,the peak systolic longitudinal velocity （Vsl）,the peak diastolic longitudinal velocity （Vel）,the peak systolic longitudinal strain （SI）,and strain rate （SRI） in 18 segments were measured in each group.Results TvI in the control group and each group with PH was reduced from basal to apical segment,and in control group Tvl in various segments of the same wall and in different walls showed no significant difference （P ＞0.05）.With increase in pulmonary artery pressure,Tvl values measured showed an increasing trend in groups with PH.In groups with PH,Vsl and Vel of each wall were reduced sequentially from basal to apical segments,showing gradient change; Vsl and Vel values measured showed a decreasing trend with increase in pulmonary artery pressure,in which the differences of Vel values measured in the control group and the mild PH group were statistically significant （P ＜0.01）,and the differences between other groups were statistically significant （P ＜0.01）.In groups with PH,SI and SRI in basal segment and the middle segment of each wall were decreased; the difference between groups was statistically significant （P ＜0.01）.Conclusions Asynchronization of the LV and decreased left ventricular function were present in patients with chronic PH;WI technology can accurately evaluate left ventricular function in patients with PH,and indicators such as Tvl,Vsl,and Vel are valuable.
文摘Background The velocity vector imaging is an ultrasound speckle imaging that was recently developed, which is based on the two-dimensional gray scale image, with more accurate tracking process and more conve-nient and time-saving operation method can quantitatively displays the varied curve of myocardial velocity and direction sampling taking from multiple parts in one cardiac cycle by tracking the space motion of echo spots of the cardiovascular tissue, and then analyze their movements, avoiding the angular dependence and the limita-tions of analysis section that could effect on Doppler technology. The technology provides a new auxiliary method for the diagnosis and treatment of cardiovascular disease and is valuable on clinical diagnosis and scientific re-search and a wide horizon of development.
文摘Side-looking SAR raw data can be obtained from the commercial market. Comparatively, in other modes such as squint SAR and spotlight SAR and the real flight echo data are hardly acquired. A new approach called the integrated velocity transformation is presented in this paper, which can approximately transform the side-looking raw data to a squint mode. The simulation proves the method is acceptable.
文摘INTRODUCTIONlschemic stroke accounts for 70% of all the cerebrovascular diseases. Severe stenosis and occlusions ofextracranial and intracranial artery are all important risk factors causing ischemic stroke. Based on the widespread observation worldwide, intracranial atherosclerosis is the most common vascular lesions in Asians, Hispanics, and Africans. Therefore, accurate and noninvasive methods fbr early diagnosis of stroke in individuals without significant stenosis of the extracranial carotid artery is of considerable clinical interest.
