Validation of a Fully Automatic Method for the Routine Selection of the Anterior and Posterior Commissures in Magnetic Resonance Images

The anterior and posterior commissures (AC and PC) typically form the reference points of the stereotactic coordinate system. Hence any discussion of target localization is limited by the variability of AC and PC selection. In an earlier study, which was performed using manual selections of AC and PC by 43 neurosurgeons, we showed that intersurgeon variability has a substantial impact on the localization of deep brain stimulation targets. We have developed and validated a fully automatic and robust AC and PC selection system that can be routinely used clinically. In this study, we show that this system is capable of localizing the AC and PC points with an accuracy that is better than that achieved clinically by manual selection, 0.65 mm (95% confidence interval: 0.56-0.79) versus 1.21 mm (95% confidence interval: 0.91-1.47) for AC and 0.56 mm (95% confidence interval: 0.46-0.66) versus 1.06 mm (95% confidence interval: 0.82-1.26) for PC.