The correlation of occupancy and linear density. The Pearson correlation coefficients (r) of occupancy vs. linear density rendered by ILEE and MGT (shown in Fig. 6) are calculated. The occupancy and linear density generally have a very high linear correlation, indicating that they agree with each other on evaluating the cytoskeletal density. ILEE and MGT does not display the same mathematical relationship, indicating that ILEE and MGT possess different tendencies in rendering the topological structure (mostly influencing linear density). In the 3D mode, they only have medium-strong correlation, potentially because (1) the 3D topological structure cannot be perfectly rendered due to concave/convex structures present in the skeletonized images and (2) 3D mode abandoned the oversampling process that 2D mode supports, due to insufficient computational power.