  Supervised deep learning offers great promise to automate analysis of medical
images from segmentation to diagnosis. However, their performance highly relies
on the quality and quantity of the data annotation. Meanwhile, curating large
annotated datasets for medical images requires a high level of expertise, which
is time-consuming and expensive. Recently, to quench the thirst for large data
sets with high-quality annotation, self-supervised learning (SSL) methods using
unlabeled domain-specific data, have attracted attention. Therefore, designing
an SSL method that relies on minimal quantities of labeled data has
far-reaching significance in medical images. This paper investigates the
feasibility of deploying the Masked Autoencoder for SSL (SSL-MAE) of TransUNet,
for segmenting bony regions from children's wrist ultrasound scans. We found
that changing the embedding and loss function in SSL-MAE can produce better
downstream results compared to the original SSL-MAE. In addition, we determined
that only pretraining TransUNet embedding and encoder with SSL-MAE does not
work as well as TransUNet without SSL-MAE pretraining on downstream
segmentation tasks.
