摘要：Objective To evaluate the accuracy of a three-dimensional (3D) magnetic position sensor system in the quantification of ventricular stroke volumes in a dynamic *** A latex balloon model of the left ventricle was suspended in a water bath connected to a pump producing 10 different pulsatile stroke volumes (15-65mi/beat). Scanning was performed using a 5.0 mHz transducer mounted with a Flock of Birds (FOB) magnetic receiver (GE System Five). The probe was scanned to sweep continuously across and over the balloon volume over 3 - 7 seconds. Digital loops were stored on magneto-optical disks and reviewed retrospectively using 3D Echopac software (GE)based on Simpson's method and compared with a two-dimensional (2D) biplane area-length method (1/2L x R) measurements at end systole and end diastole. Both 3D and 2D derived stroke volumes were compared with the reference stroke volume calculated by direct measurement of balloon *** There was an improved correlation between 3D stroke volume and reference stroke volume ( y = 0.91 x + 0.41, r = 0.97, SEE = 2.83 ml, P = 0.0001 ) compared to 2D stroke volume and reference stroke volume (y=0.49x+8.68, r=0.87, SEE=3.87 ml, P=0.0011, difference between 2D and 3D P＜0.003).Conclusion 3D magnetic FOB scanning is practical, accurate and should facilitate assessment of left ventricular function.