Doppler studies can detect the relative increase in flow velocity seen in the jet of flow within the stenosis itself. The severity of the obstruction can be estimated by comparing the higher velocity within the stenotic area with the lower velocities obtained immediately proximal to the obstructing lesion. Provided that the proximal velocity is not abnormally high, a modified Bernoulli equation can be used to estimate the peak pressure drop across the stenosis.

To read more or access our algorithms and calculators, please log in or register.