ASSESSMENT OF THE ACCURACY OF COLOR DOPPLER FLOW MAPPING BY DIGITAL IMAGE-ANALYSIS

An in vitro steady pow experiment was performed in order to test the a ccuracy of velocity measurements obtained through color Doppler flow m apping (CDFM). Using the American Society of Echocardiography (ASE) fl ow phantom, low (maximum velocity = 60 cm/sec), medium (maximum veloci ty = 300 cm/sec) and high (maximum velocity = 600 cm/sec) speed accele rating flow fields, in which multiple aliases were visible, were image d. A fully automatic computer algorithm was used to unwrap the aliases and to convert the CDFM to digital velocity. Packet size and wall fil ter frequency on the ultrasound machine were varied and the measured v elocity compared to the true velocity. The results show that the veloc ity obtained in this way from the CDFM is very accurate at the low and medium velocities, but for the high velocity the turbulence is too in tense to obtain an accurate result. There was no marked difference bet ween the data for different packet sizes or wall filter settings.