Calculation of mitral regurgitant fraction by automated analysis of Doppler power spectrographs

Mitral regurgitation (MR) associated with valve incompetence is an increasingly recognised clinical problem. The mitral regurgitant fraction (MRF) is a quantitative index of MR severity and is a valuable aid in decision making regarding need for and timing of surgical intervention. It is also a useful post-intervention outcome measure. Currently no reliable non-invasive means of assessing MRF is available and the gold standard remains the invasive procedure of left-ventriculography, a procedure itself not inherently highly accurate and both costly and inconvenient to regularly perform. We have recently proposed a non-invasive, and therefore repeatable, method of assessment of MR based on the received power of the backscattered Doppler signal obtained during conventional trans-thoracic echocardiographic investigation. The technique has however suffered from the drawback of requiring time-consuming manual analysis of videotaped data images with associated unavoidable inter- and intra-observer inaccuracies. We have now developed an automated technique for the detection of the Doppler flow waveforms that significantly reduces the processing time and minimises the need for a skilled operator.