THE RADIOLOGICAL MANIFESTATION AND CLASSIFICATION OF THE VERTEBRAL ARTERY SULCUS RING OF ATLAS IN 56 PILOTS / 解放军医学杂志

The presence of the cervical artery sulcus ring was found on the atlas in 56 out of 346 air pilots. The X ray appearance could be classified as follows. Type Ⅰ:Complete sulcus ring in 32 cases, in whom the sulcus might be complete unilaterally or bilatrally. Type Ⅱ: Incomplete or half ring in 18 cases. This type could be further divided into Ⅱ a , consisting of 4 persons with half ring in the anterior aspect, andⅡ b , half ring posteriorly in14 persons. Type Ⅲ: Broken ring in 6 persons. It is an anatomic variation, which may be have some relationship to vertigo. It is suggested that the presence of cervical artery sulcus ring on atlas should be taken as an disqualification factor in air pilot recruitment.