IXI-TN: trigeminal nerve labels and a known-rigid perturbation protocol for MRI-MRA registration evaluation

Bilateral trigeminal nerve labels for 40 subjects of the IXI dataset (Hammersmith Hospital subset, Philips 3 T; paired T2-weighted MRI and TOF-MRA), together with the known-rigid perturbation protocol used as the public reproduction layer of the TN-Reg-Benchmark for MRI–MRA registration evaluation in trigeminal neuralgia. Contents: labels/ (one NIfTI label map per subject on the native IXI T2 grid; cisternal segment of the trigeminal nerve, left and right; no vessel labels), manifest.csv (IXI ID, side, ROI centre and the 48³-voxel ROI definition at 0.47 mm isotropic), perturbation/ (640 rigid transforms: rotations of 5°, 10° and 20° about a random axis, translations of 5, 10, 20 and 40 mm in a random direction, and a combined 10° + 10 mm level, two draws per subject per level; as CSV and ANTs 4×4 matrices), README.md. The labels were drawn by one annotator on the T2 image alone, without reference to the MRA or to any registration output, following the annotation protocol of the clinical cohort described in the paper. The IXI images are not included; download them from https://brain-development.org/ixi-dataset/. Derived from the IXI dataset (CC BY-SA 3.0); released under CC BY-SA 4.0. Evaluation code: https://github.com/jhuldr/TN-Reg-Benchmark. If you use these labels, please cite: Zhang X. et al., Evaluation Principles for MRI–MRA Registration in Trigeminal Neuralgia: An ROI-Centered Neurovascular Benchmark, arXiv:2609.08805 (2026).