In vivo validation of image-directed Doppler measurement of superior mesenteric artery blood flow.

Image-directed Doppler measurement of superior mesenteric artery blood flow in volunteers was validated in two artificial models with either a venous or an arterial flow profile. In the "venous" model, the Doppler device overestimated the real flow velocity by 86 +/- 7%, and in the "arterial" model by 24 +/- 9%. The areas under the time-frequency curves (AUCs) from the arterial model were measured by planimetry. A correction factor of 1.47 between flow velocities calculated after planimetry and real flow was established. Correction for this factor resulted in a flow velocity of 19.5 +/- 4.7 cm/s and a blood flow rate of 377 +/- 166 ml/min in the volunteers.