Interpretable unsupervised learning enables accurate clustering with high-throughput imaging flow cytometry.

Journal: Scientific reports
PMID:

Abstract

A primary challenge of high-throughput imaging flow cytometry (IFC) is to analyze the vast amount of imaging data, especially in applications where ground truth labels are unavailable or hard to obtain. We present an unsupervised deep embedding algorithm, the Deep Convolutional Autoencoder-based Clustering (DCAEC) model, to cluster label-free IFC images without any prior knowledge of input labels. The DCAEC model first encodes the input images into the latent representations and then clusters based on the latent representations. Using the DCAEC model, we achieve a balanced accuracy of 91.9% for human white blood cell (WBC) clustering and 97.9% for WBC/leukemia clustering using the 3D IFC images and 3D DCAEC model. Above all, although no human recognizable features can separate the clusters of cells with protein localization, we demonstrate the fused DCAEC model can achieve a cluster balanced accuracy of 85.3% from the label-free 2D transmission and 3D side scattering images. To reveal how the neural network recognizes features beyond human ability, we use the gradient-weighted class activation mapping method to discover the cluster-specific visual patterns automatically. Evaluation results show that the automatically identified salient image regions have strong cluster-specific visual patterns for different clusters, which we believe is a stride for the interpretable neural network for cell analysis with high-throughput IFCs.

Authors

  • Zunming Zhang
    Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA, 92093, USA.
  • Xinyu Chen
    State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China.
  • Rui Tang
    State Key Laboratory of Earth Surface Processes and Resource Ecology, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China.
  • Yuxuan Zhu
    Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA, 92093, USA.
  • Han Guo
    College of Electrical Engineering, Zhejiang University, Hangzhou, 310000, China.
  • Yunjia Qu
    Department of Bioengineering, Institute of Engineering in Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0435, USA.
  • Pengtao Xie
    Department of Electrical and Computer Engineering, University of California San Diego, San Diego, USA. p1xie@eng.ucsd.edu.
  • Ian Y Lian
    Department of Biology, Lamar University, Beaumont, TX, 77710, USA.
  • Yingxiao Wang
    Department of Bioengineering, Institute of Engineering in Medicine, University of California, San Diego, San Diego, CA, United States.
  • Yu-Hwa Lo
    Department of Electrical and Computer Engineering, University of California, San Diego, California.