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Balvan, J.

Publications and source records attributed to Balvan, J..

2 recordsLinked to original sources

Self-Supervised Pretraining for Transferable Quantitative Phase Image Cell Segmentation

In this paper, U-Net-based method for robust adherent cell segmentation for quantitative phase microscopy image is designed and optimised. We designed and evaluated four specific post-processing pipelines. To increase the transferability to different cell types, non-deep learning transfer with adjustable parameters is used in the post-processing step. Additionally, we proposed a self-supervised pretraining technique using nonlabelled data, which is trained to reconstruct multiple image distortions and improved the segmentation performance by from 0.67 to 0.70 of Object-wise Intersection over Union. Moreover, we publish a new dataset of manually labelled images suitable for this task together with the unlabelled data for self-supervised pretraining. Graphical Abstract O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY HighlightsO_LIFour strategies for instance cell segmentation with U-Net were compared. C_LIO_LISpecialised post-processing pipelines with tunable/optimizable parameters were designed for each segmentation strategy. C_LIO_LITransferability to different cell types by optimisation of post-processing parameters was tested. C_LIO_LIThe proposed self-supervised pretraining method improved both segmentation performance and transferability to different cell types. C_LIO_LIA new manually labelled quantitative phase imaging dataset for cell segmentation with unlabelled data for self-supervised pretraining was created. C_LI

bioinformatics↗

Detection and characterization of apoptotic and necrotic cell death by time-lapse quantitative phase image analysis

Cell viability and cytotoxicity assays are highly important for drug screening and cytotoxicity tests of antineoplastic or other therapeutic drugs. Even though biochemical-based tests are very helpful to obtain preliminary preview, their results should be confirmed by methods based on direct cell death assessment. In this study, time-dependent changes in quantitative phase-based parameters during cell death were determined and methodology useable for rapid and label-free assessment of direct cell death was introduced. Our method utilizes Quantitative Phase Imaging (QPI) which enables the time-lapse observation of subtle changes in cell mass distribution. According to our results, morphological and dynamical features extracted from QPI micrographs are suitable for cell death detection (76% accuracy in comparison with manual annotation). Furthermore, based on QPI data alone and machine learning, we were able to classify typical dynamical changes of cell morphology during both caspase 3,7-dependent and independent cell death subroutines. The main parameters used for label-free detection of these cell death modalities were cell density (pg/pixel) and average intensity change of cell pixels further designated as Cell Dynamic Score (CDS). To the best of our knowledge, this is the first study introducing CDS and cell density as a parameter typical for individual cell death subroutines with prediction accuracy 75.4 % for caspase 3,7-dependent and -independent cell death.

cell biology↗