Fig. 4
From: The role of ultrasound imaging in vascular compression syndromes
a Standard radiography showing a cervical rib on the right (arrow). b Color Doppler US examination, performed with lowered arms, shows a regular diameter (12 mm) and a regular flow-C of the right subclavian artery. d Color Doppler US examination with raised arms shows artifacts due to turbulent flux. E: Duplex Doppler US shows increase in peak speed (105 cm/s)