Morphological evaluation of a regurgitant orifice by 3-D echocardiography:Applications in the quantification of valvular regurgitation

The clinical evaluation of blood flow regurgitation through a heart valve o r stenotic lesion is an unresolved problem, The proximal flowfield region h as been the study focus in the last few years; however, investigators have failed to identify an accurate and reliable calculation scheme due to lack of geometric information about the shape and size of the regurgitating or s tenotic orifice. Presented here is a superior method of calculation, by usi ng three-dimensional (3-D) echocardiography combined with Doppler velocimet ry. The geometric structure of the orifice in a regurgitating porcine prost hetic valve in vitro was formulated by 3-D image construction of sequential ly obtained 2-D images. The velocity flowfield was accessed by color Dopple r flow mapping (CD) and continuous-wave Doppler (CW), Two accurate methods of calculation of regurgitant variables were developed. The first method ca lculated peak regurgitant flow rate from CD and the second method calculate d regurgitant flow volume from CW, Both methods showed excellent correlatio n with the corresponding true values from an electromagnetic flowmeter. The promising preliminary results in such a realistic porcine model indicate t he possibility of establishing a routine procedure to be tested in the clin ical setting. (C) 1999 World Federation for Ultrasound in Medicine & Biolog y.