Standardized method for the measurement of Grabb's line and clival-canal angle

摘要

OBJECTIVE Grabb's line the perpendicular distance from the basion-C2 line (pB-C2) is a widely used radiographic measurement with significant clinical implications in patients with a complex Chiari malformation. Rigorous demonstration of the reproducibility of this measurement has not previously been reported. The authors report a standardized measurement technique with excellent inter-and intrarater reliability on T1-weighted sagittal MRI.