Pressure gradient determination by three dimensional Doppler ultrasound [medical haemodynamics]

A three-dimensional formulation was used to quantitate the maximal velocity in a flow jet produced by circulating a Doppler acoustic fluid through a Pasteur pipette in an open recirculating system. The flow jet velocity, as determined from the three-dimensional vector magnitude, was 119.7±3.17 cm/s; the actual velocity of 119.6 cm/s was determined with an Aalborg ball flowmeter. Doppler velocities for calculation of pressure using the Bernoulli equation were within 3.9% of actual jet stream velocities. The three-dimensional ultrasound Doppler velocity of a flow jet detemined at the site of the maximal pressure gradient should lead to a more accurate determination of pressure drop through a structure, stenosis, or septal defect using the Bernoulli equation