The paper uses Dice Coefficient for the evaluation of their model which is common in such semantic segmentation tasks. The article is written for lay audience hence the use of "accuracy".

    Dice Coefficient = 2 * the Area of Overlap divided by the total number of pixels in both images.

0. https://www.nature.com/articles/s41467-020-19449-7#Abs1 1. https://towardsdatascience.com/metrics-to-evaluate-your-sema...