but on the late films retrograde flow was demonstrated in the left vertebral artery. Since it was assumed that the reversal of flow in the left vertebral artery was of the same magnitude as the ...

was found. The lumen of the vertebral artery at the orifice was not over 1 mm. in diameter, but retrograde flow from above downward upon release of the occluding clamp was vigorous. A left ...

In addition, in cases of subclavian steal from the vertebral artery, there is a graded system ... Grade II lesions show retrograde flow during systole and antegrade flow during diastole.