Automatic Detection and Measurement of Fetal Biparietal Diameter and Femur Length—Feasibility on a Portable Ultrasound Device

An automatic method able to recognize a presented section through the biparietal plane of the fetal head and a section through the fetal femur in ultrasound images is developed. Once the correct anatomical section for measurement is identified by the machine, the placement of the measurement calipers is automatically determined by fitting an active contour model to the structure of interest. The fetal biparietal diameter (BPD) and femur length (FL) are then measured automatically. The validation data set contained 167 and 197 Bmode images for BPD and FL measurements, respectively. The images were acquired using 4 different ultrasound scanners, which resulted in varied image quality and gain settings. The mean gestational age (GA) of the fetuses was 19.4 weeks, range 16 to 41 weeks. A measurement success rate of 90% was achieved for both BPD and FL. The correlation coefficients between the manual and automatic measurements were 0.995 (BPD) and 0.967 (FL), mean errors were 0.5 mm (BPD) and -1.7 mm (FL) and error range with 95% confidence interval (CI) were −3.8 4.8 mm (BPD) and −11.4 8.1 mm (FL). The automatic measurement results were consistent in both high and low gain settings. The intraclass correlation coefficients between manual and automatic measurements were 0.995 (95% CI; 0.981 0.999) for BPD in high gain, 1.0 (95% CI; 0.998 1.0) for BPD in low gain, 0.998 (95% CI; 0.991 0.999) for FL in high gain and 0.999 (95% CI; 0.996 1.0) for FL in low gain settings. The method was implemented on a prototype, portable ultrasound machine designed to be used in lowand middle-income countries (LMIC). The overall performance of the method supports our hypothesis that automated methods How to cite this paper: Khan, N.H., Tegnander, E., Dreier, J.M., Eik-Nes, S., Torp, H. and Kiss, G. (2017) Automatic Detection and Measurement of Fetal Biparietal Diameter and Femur Length—Feasibility on a Portable Ultrasound Device. Open Journal of Obstetrics and Gynecology, 7, 334-350. https://doi.org/10.4236/ojog.2017.73035 Received: February 27, 2017 Accepted: March 20, 2017 Published: March 23, 2017 Copyright © 2017 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access DOI: 10.4236/ojog.2017.73035 March 23, 2017