Comparison between linear array real time ultrasonic scanning and conventional compound scanning in the measurement of the fetal biparietal diameter.

Abstract

Ultrasonic measurements of fetal biparietal diameter (BPD) obtained by the Real Time scanning (Dynamic Section Scan) and conventional compound scanning (Static Section Scan) in twenty patients were compared. A comparison between two operators, one of whom was relatively inexperienced, was also made, both measuring the same BPDs. The mean variance of 20 groups-of-four 'blind' measurements was reduced using dynamic scanning, particularly for the less experienced operator. A significant difference was observed between operators using conventional scanning but not when using dynamic scanning. Both operators were able to obtain results in a shorter time with dynamic scanning, the faster operator averaging less than one minute for each observation. Apparent advantages of dynamic scanning are discussed. The terms 'Dynamic Section Scan' and 'Static Section Scan' are suggested to emphasize the difference between the two imaging systems.