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 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.

Reliability of fetal anthropometry by ultrasound

“…1). This variability is similar to that found by POLL [6] (SD = 0.76 mm) and COOPERBERG et al [3] (SD = 0.77 mm), and somewhat smaller than that found by DOCKER et al [4]. On the other hand, HUGHEY et al [5] states that when scanning is performed with medium gain (width of skull table: 3-5 mm) and measuring from outer edge to outer edge of the fetal head, the SD is 0.517mm.…”

“…It should be noted that this intra-observer variability accounts for only 2% of the BPD value. When BPD measurements were compared among observers, no significant differences were found, this has also been reported by DOCKER et al [4] when both observers used a real-time B scan. Regarding the comparison between the fetal and neonatal measurements of BPD, no significant differences were found.…”

Accuracy of an average ultrasonic laboratory in measurements of fetal biparietal diameter, head circumference and abdominal circumference

“…curacy as that reported by CAMPBELL and NEWand R.T. (figure 2). These results are in agree-MAN who have estimated gestational age within ment, at least as regards BPD, with other pub-plus or minus 7 days by a single determination lished papers [12,14] and suggest that differen-of BPD before 24 weeks [5]. This relatively low ces in confidence limits of standard growth degree of precision is by far better than that curves at different gestational ages mainly re-provided by certain dates, which has been reflect biological variability rather than the ported to vary between plus or minus 29 days degree of accuracy.…”

The Reproducibility of Fetal Crown Rump Length Measurements Obtained With Real Time Ultrasound Systems Compared With Those of a Conventional B‐scanner

“…Thus variability of CRL measurement with every machine is small in terms of gestational age and justifies the use of real time machines to establish gestational age.THE measurement by sonar of fetal crown rump length (CRL) in the first trimester of pregnancy is a recognised method of establishing gestational age (Robinson, 1973;Drumm et al, 1976). Real time ultrasound systems, because of their portability (Balfour, 1978) and their ease of use, especially by inexperienced operators (Docker and Settatree, 1977), are particularly suitable for this role.Adam et a1 (1979) have shown a good correlation between CRL measurements made with one type of real time machine and a static 734…”