Quantitative Assessment Of Valve Reguritation By Real-time Tri-plane Echocardiography

Part 1Objective To set up a vitro mode to imitate the valve regurigtation and to establish the true control of the quantification assessment of the valve regurgation by real-time tri-plane echocardiography.Mehtods and principle Basing the principle of pressure of fluid p=ρgh, to keep a stabilizaed gradient through the orification by keep a given altitude of the fluid.Control the open time of the electromagnetically operated valve by using a timer.1)The water tank and self-made measuring glass was connected by a gas pipe which inner diameter is 1.5cm.And keep in the three difference height between the water tank and the measuring glass.2)A hole was drilled in the center at the top of the casing of single-use syringes with different diameters 2mm,3mm,4mm,5mm,6mm 7mm,8mm,9mm,10mm to imitate regurgitation orific.3)Bean milk which temperature was at 24-27°c and specific density was controled at 1.005-1.006. 4)The real-time three-dimensional transducer of 4V(GE VV7 DIMENSION)was fixed above the water tank by a bracket to detect the color Doppler flow image of imitated valve regurgitation.Results 1)The lasting time of imitated regurgitation was longer(0.5±0.02s) than the set time(0.4s)by the timer.2)Lasting time of imitated regurgitation set at 0.4s,the gradient through the orification set at 160cm,100cm,60cm of the height of fluid,the error volumes of imitation regurgitation through orifics(inner diameter 2mm,4mm,6mm,8mm)were not more than 2.5 ml.3)Volumes of imitation regurgitation through orifics was not increase when the diameter of the orfic was over 8mm,demonstrating the size of orfic of the electromagnetically operated valve not more than 8ram.4)The shape of the volume of the reguigitatin was a spindle observed in real-time tri-plane color doppler echocardiography.Conclusions The self-made vitro mode can imitate the valve regurgitation. Using the mode,the control can be established between the volume measured in the real-time tri-plane echocardiography and the real volume through orific.Part 2The feasibility study on valve regurgitation quantification with real-time three dimensional echocardiograph in tri-plane color doppler mode____vitro studyObjective To validate the feasibility of mitral quantification with real-time three-dimensional echocardiography(RT-3DE)in tri-plane color doppler mode.Mehtods The volumes of color doppler of imitation regurgitation were observed and measured in real-time three-dimensional echocardiograph in tri-plane color doppler mode using self-made regurgitation mode with the different instrument condition.The diameter of regurgitation orifice were selected with 2mm,4mm,6mm, 8mm.The gradient of pressure was controled under the height of water at 160cm, 100cm,60cm.Result The regurgitant flow volume measured with 3D color doppler imaging were increased with the increase of gain and power and lower of the color bar. However there were no difference between the volume measured with 3D color doppler imaging and the real volume under the appropriate instrument condition.Conclusions It is feasible to quantify the mitral regurgitation with real-time three-dimensional echocardiography(RT-3DE)in three-section color doppler mode. But the accuracy of the quantification is influenced by the instrument condition. Part 3vena contracta width and the flow convergence method in the quantitive assessment of valvular reguigitation by real -time tri-plane echocardiography____vitro studyObjective To evaluate the accuracy and effect factor in the quantiation of valve regurgitation with vena contracta width and the flow convergence method by real -time tri-plane echocardiography.Methds The vena contracta width and the flow convergen of different diameter orifice(2mm,4mm,6mm,8mm)were observed and measured in different gradient and different instrument condition by real -time tri-plane echocardiography.Results flow rate that measured by the convergence method.The vena contracta width did not vary with the transvalvular gradient and color bar(P＞0.05,p＞0.05),but it was correlated with the gain(p＜0.05).The vena contracta width was signdficantly correlated with the diameter of the orifice,r=0.854 when gain was set at -20db.The width increased with the increase of gain.While the transvalvular gradient influenced the flow rate measured by the flow convergence significantly(p＜0.05).Conclusion Vena contracta widthes are easy to measure and can be used to assess the valvular regurgitation and do not vary with the transalvular gradient but the gain of color doppler influences the width.The flow convergence method is a accurate method to quantitive assess valvular reguigitation and corelated to the transvalvular gradient.