Benjamin ­Hohlmann

Segmentation of the Scaphoid Bone in Ultrasound Images: A comparison of two machine learning architectures for in-vivo segmentation

Publication Info

  • Author
    B. Hohlmann
    P. Brößner
    K. Radermacher 
  • Conference
    CURAC
  • Publisher
    De Gruyter
  • Date
    2021
  • Link
    https://www.degruyter.com/document/doi/10.1515/cdbme-2021-1017/html
  • PDF „CURAC 2021b“

Abstract

For the percutaneous fixation of scaphoid fractures, navigated approaches have been proposed to facilitate screw placement. Based on ultrasound imaging, navigation can be carried out in a cost-effective and fast manner, furthermore avoiding harmful radiation. For this purpose, a fast and efficient architecture for the automated segmentation of scaphoid bone in ultrasound volume images is needed.

Methods

For 2D segmentation of the scaphoid, two architectures are taken into account: 2D nnUNet and Deeplabv3+. These architectures are trained and evaluated on a newly created dataset consisting of 67 annotated in-vivo ultrasound volume images (4576 slice images).

Results

In terms of Dice coefficient, the 2D nnUNet achieves 0.67 compared to 0.57 for the Deeplabv3+. In terms of distance metrics, the 2D nnUNet shows an average symmetric surface distance error of 0.66mm, while the Deeplabv3+ achieves 0.55mm.

Conclusion

Fast and accurate segmentation of the scaphoid in ultrasound volumes is feasible. Both architectures show competitive results.

Ultrasound image depicting the scaphoid, recognizable due to its characteristic “bone shadow”. Image (upper left), GT annotation (blue, upper right), prediction of 2D nnUNet (red, lower left), prediction of Deeplabv3+ (green, lower right).