Variability and Landmark Quality in Anatomical Co-Registration in Neuronavigation for Brain Stimulation

Marked and unmarked localization of 13 facial and cranial landmarks in neuronavigation shows operator- and landmark-specific variability, with median within-operator precision 1.60 mm and median inter-operator distance 2.91 mm.

• Why it matters: Neuronavigation accuracy depends on reproducible physical localization of anatomical landmarks, yet variability by operator and landmark—and the effect of marking—has not been quantified at this scale.
• What they did: In 19,630 measurements from 16 participants, four operators, and 13 landmarks, the study analyzed within-operator precision, inter-operator agreement, and marked–unmarked displacement under marked and unmarked conditions.
• The result: Marking did not significantly improve overall within-operator precision, but reduced inter-operator distances by 29.2% and revealed systematic directional between-operator offsets approaching 1.5 mm, supporting landmark-specific quality control.