  Left ventricular segmentation is essential for measuring left ventricular
function indices. Segmentation of one or several images requires an initial
guess of the contour. It is hypothesized here that creating an initial guess by
first detecting anatomical markers, would lead to correct detection of the
endocardium. The first step of the algorithm presented here includes automatic
detection of the mitral valve. Next, the apex is detected in the same frame.
The valve is then tracked throughout the cardiac cycle. Contours passing from
the apex to each valve corner are then found using a dynamic programming
algorithm. The resulting contour is used as an input to an active contour
algorithm. The algorithm was tested on 21 long axis ultrasound clips and showed
good agreement with manually traced contours. Thus, this study demonstrates
that detection of anatomic markers leads to a reliable initial guess of the
left ventricle border.
