This dataset contains whole-brain functional Ultrasound Imaging (fUSI) recordings and associated behavioral/physiological signals collected in head-fixed , freely running mice, under conditions of spontaneous behaviour.The files are processed data, including Power Doppler data for all acquisitions performed for the following study: A Landemard, M Krumin, KD Harris, and M Carandini, "Brainwide blood volume reflects opposing neural populations", bioRxiv 2025 (Nature, 2026).After downloading, please unzip the zipped directories. The repository is in the BIDS format, organized as follows:fUSI power-Doppler runs: sub-/fusi/_pwd.nii.gz with JSON sidecars.Whisker activity (when available): sub-/fusi/_recording-whisking_physio.tsv.gz,Eye position (when available): sub-/fusi/_recording-eye_physio.tsv.gz,Running wheel signals (when available) sub-/fusi/_recording-wheel_physio.tsv.gz (+ JSON sidecars).One angiography scan per subject: sub-/angio/_pwd.nii.gz (+ JSON sidecars).Per-subject acquisition tables: sub-/sub-_scans.tsv.Atlas alignment and processed derivatives.The code to analyze these files is available on GitHub, at https://github.com/agneslandemard/fusi_analyses