EP22.17: Automatic detection and measurement of bi‐dimensional fetal head planes from 3D ultrasound volumes using a prototype tool

Abstract

To test a tool able to automatically extract bi-dimensional (2D) fetal head planes and measurements from 3D ultrasound volumes. Ultrasound volumes (3D) and measurements (2D) of the fetal head were acquired in women with singleton pregnancies at 18-24 weeks. The biparietal diameter (BPD), occipitofrontal diameter (OFD) and head circumference (HC) were measured manually. The “Fetal Brain Plane Finding Prototype” tool (Philips Healthcare) was used to automatically extract 2D planes from the 3D volume in the transventricular (TV), transthalamic (TT) and transcerebellar (TC) planes; and to automatically measure BPD, OFD and HC on these extracted planes. Quality assessment consisted of (1) assessment whether the correct plane was extracted; (2) scoring of the quality of the plane using predefined criteria (0-5); (3) whether image quality was “acceptable” or “not acceptable” for clinical purposes. In addition, the agreement between automatic and manual measurements was expressed in actual measurement units (mm) and in percentage terms to account for changes in fetal size with increasing gestational age. Manual measurements and 3D volume acquisition were performed in 170 pregnancies; automatic extraction of all three planes and measurements were successful in 143 (84%) volumes. Out of the 429 extracted planes, 92% were correctly identified as TV, TT or TC and 85% were deemed to be acceptable for clinical purposes. The average score was 4.7, with only 17 planes scoring 3 or less. The variability (95% limits of agreement) between automatic and manual measurements for BPD, OFD and HC was ±4.88%, ±4.19% and ±2.75%, respectively. Automatic extraction of 2D fetal head planes and measurements from 3D ultrasound volumes showed good results overall. This could be used in future to facilitate and speed up the exam process, while maintaining accuracy of the exam.