sphero-vem ========== **sphero-vem** is a Python library for end-to-end quantitative analysis of volume electron microscopy (vEM) data, with a focus on 3D cell and nucleus morphology and nanoparticle (NP) localization and quantification in tumor spheroid models. It covers the full analysis pipeline from raw image ingestion to per-label quantitative property extraction, with GPU acceleration throughout: automatic via CuPy and CuCIM for array operations, and PyTorch-native for registration and segmentation. Cell and nucleus segmentation builds on `Cellpose-SAM `_, self-supervised denoising on `CAREamics `_, and image registration on `PyTorch `_. Originally developed for SBF-SEM imaging of gold nanoparticle (AuNP) distribution in FaDu head-and-neck tumor spheroids, the pipeline is designed to generalize to other vEM modalities and biological specimens. **sphero-vem** accompanies the paper: Bottone et al., *3D Reconstruction of Nanoparticle Distribution in Tumor Spheroids with Volume Electron Microscopy*, 2026. `https://doi.org/10.64898/2026.04.17.719153 `_ The annotated dataset is publicly available at `BioImage Archive (S-BIAD3263) `_, and finetuned model weights for cell and nucleus segmentation are available on `Zenodo `_. .. toctree:: :maxdepth: 2 :caption: Contents installation pipeline api/index