A new string phantom with Four independent variables for evaluation of doppler ultrasonography instruments

The porpose of this paper was design and construction of a new string phantom for testing doppler ultrasonography instruments with four independent variables including target velocity, depth, angle an lateral probe to target distance. The velocity accuracy of 10 doppler ultrasonography instruments were tested by the phantom and dependence of the velocity accuracy of instrument to target depth, angle and velocity were investigated. Doppler accuracy was found to be significantly dependent on the target angle (p<0.01), but target depth and velocity did not do so.