Cellthick

Cellthick is a quantitative metric used in cell biology and histology to describe the effective thickness of a cell along the imaging axis, typically the z-axis in microscopy data. The term is not universally standardized, but in imaging pipelines it denotes the distance between defined internal boundaries within a cell, such as apical and basal membranes or nucleus-to-cytoplasm interfaces, measured on a per-pixel or per-region basis.

Measurement relies on three-dimensional image acquisition, usually by confocal or two-photon microscopy, with z-stacks or optical coherence tomography. After segmentation identifies the boundaries of the cell and its substructures, thickness at a given x,y position is computed as the distance along the local normal to the boundaries. Analysts may report cellthick as a local value, an average over a region (cellthick_mean), a median (cellthick_median), or a distribution, along with dispersion measures.

Applications include characterizing cell morphology in epithelial layers, comparing structural changes in development or disease, and informing models of tissue architecture in 3D culture. Because cellthick depends on imaging modality, staining, and segmentation quality, it is typically used in conjunction with other morphometric metrics such as cell diameter, volume, and surface area.

Standards emphasize consistent acquisition parameters (voxel size, z-step, and calibration with micrometer standards), explicit direction of thickness measurement, and transparent reporting of segmentation methods. Limitations include anisotropic voxels, marker bias, and segmentation errors, which can bias thickness estimates, particularly in crowded or irregular tissues.

See also: cell height, epithelial thickness, z-stack analysis, tissue thickness.