VP40.20: Standard biometric planes: what are the salient anatomical landmarks?


Objectives: During acquisition of standard biometric planes, sonographers must accurately identify several anatomical landmarks. Using operator gaze tracking and novel machine learning techniques, we aimed to determine and compare the salient anatomical landmarks of standard fetal biometric planes used in practice for second and third trimester scans. Methods: We prospectively collected video recordings of entire routine ultrasound scans coupled with operator eye tracking. Using deep learning algorithms, we automatically detected the anatomical landmarks that sonographers fixate on and pay attention to while acquiring the three basic standard biometric planes: head circumference (HC), abdominal circumference (AC) and femur length (FL). Results: We analysed 242 and 204 HC, 256 and 257 AC, 236 and 218 FL planes in the second and third trimesters, respectively. These scans were performed by 15 sonographers. Within each plane, sonographers spend a different proportion of time observing the various anatomical landmarks. Comparing second and third trimester scans, we found that operators look at standard biometric planes differently: the most notable differences between the trimesters are in the HC plane for the lateral ventricle (91.3% vs. 42.7%, p < 0.001) and midline (38.0% vs. 65.7%, p < 0.001, figure 1). Conclusions: While acquiring standard biometric planes, sonographers spend an uneven proportion of time observing the different anatomical landmarks, and sonographer’s attention also differs comparing second and third trimester scans.

Ultrasound in Obstetrics & Gynecology

*L. Drukker and R. Droste contributed equally to this work.

Figure 1


  author = {Drukker, L. and Droste, R. and Noble, A. and Papageorghiou, A.T.},
  title = {VP40.20: Standard biometric planes: what are the salient anatomical landmarks?},
  journal = {Ultrasound in Obstetrics \& Gynecology},
  volume = {56},
  number = {S1},
  pages = {235-235},
  doi = {10.1002/uog.22958},
  url = {https://obgyn.onlinelibrary.wiley.com/doi/abs/10.1002/uog.22958},
  eprint = {https://obgyn.onlinelibrary.wiley.com/doi/pdf/10.1002/uog.22958},
  year = {2020}