Bidirectional flow in the right vertebral artery

The duplex ultrasound was obtained from a 77-year-old female with peripheral artery disease and coronary heart disease with prior coronary angioplasty, as well as right carotid endarterectomy for asymptomatic high-grade carotid stenosis. On duplex ultrasound, bidirectional flow can be seen in the right vertebral artery and was due to progression of stenosis in the brachiocephalic trunk.