Multi-temporal Globally-Optimal Dense 3-D Cell Segmentation and Tracking from Multi-photon Time-Lapse Movies of Live Tissue Microenvironments

Abstract

Living immune system microenvironments can be imaged by timelapse multi-photon multi-spectral microscopy to reveal the complex tissue architecture and cell movements. Automated segmentation and tracking of these motile, numerous, and densely packed cells over long-duration 3-D movies is needed to sense and quantify subtle phenotypic differences between genetically modified and wild type cells. We present a novel multi-temporal 3-D cell tracking algorithm that: (i) implicitly models and corrects segmentation errors by exploiting spatio-temporal continuity, (ii) computes globally-optimal second-order correspondences through second-order matching in a directed hypergraph, (iii) does not require any manual initialization, and (iv) utilizes a trainable nonparametric motion model using smooth kernel density estimation. The tracking problem is formulated as a second-order hyperedge selection problem in a directed hypergraph, and solved using branch-and-cut integer programming. A quantitative study on four real datasets containing 3,361 cells showed that our algorithm reduces segmentation errors by 53% post-tracking compared to independent segmentations in every frame. In comparison, Jaqaman et al.’s u-track [1] algorithm eliminates only 38% of the segmentation errors. We found the error rate of our tracking algorithm to be 2.23%, 28.8% lesser than u-track’s error rate while comparing 7,213 track correspondences.