Reply to the letter to the editor by Brown

The vertebral artery (VA) usually enters the transverse foramen at the C6 level. Thus, surgeons prefer to insert pedicle screws (PSs) at C7, but this does not eliminate the risk of VA injury. We aimed to clarify anatomical features of the VA V1 segment at the C7 pedicle level, based on computed tomographic angiography (CTA) of 81 consecutive patients.We examined the course of the VA V1 segment on axial CTA images. VA position was classified...