Standardization of Doppler Echocardiographic Signals

J. C. Conti, Ph.D., E. R. Strope, Ph.D., D. J. Rohde, C. L. Hanawalt,* R.D.M.S., K. Scott,* R.D.M.S. Sage Ewing, Galena, MO, *St. John’s Hospital, Springfield, MO

A flow standard or phantom has been developed that allows the cardiologist to assure reliable flow velocity values. Proven technologies have been utilized to fabricate a device that generates highly reproducible and reliable pulsatile flow velocities up to 6 meters per second. Internationally recognized experts in the area of cardiovascular flow dynamics have contributed to this project.

After initial fabrication, the flow field of the flow phantom was mapped using laser Doppler anemometry. All regions within the flow field were accurate to approximately 2% with a pulse-to-pulse reproducibility of 2%. The flow phantom was then used to evaluate several clinical ultrasound machines at four medical centers. Results were mixed but indicated that nearly 30% of all the devices evaluated were irreproducible or displayed Doppler velocity signals as much as 25% in error.

Details of the design, calibration and clinical use of this device will be presented.