Quantitation of regional myocardial blood flow by contrast echocardiography

A basic theoretical approach is presented for the quantitative measurement of regional myocardial tissue blood flow based on the computer analysis of contrast enhanced echocardiographic images. Blood flow is evaluated as the ratio of the intravascular fraction, and the mean transit time of the contrast agent. Both parameters are obtained by analyzing the variations in mean videointensity in two regions of interest, defined in the left ventricular (LV) cavity and the myocardial tissue. The main transit time is computed using combined time- and frequency-domain processing, applying deconvolution of the response function. Extensive computer simulation showed that the algorithm successfully evaluates the mean transit time within 10% of error for signal-to-noise levels up to 2:1. The intravascular volume fraction is computed as a ratio of the integrated intensities in the two regions of interest. Animal experiments involving radiolabeled microspheres showed high correlation between the two independent measurements of blood flow