Figure 2. Cross-sectional illustration of the neck that depicts the anatomic relation of the carotid artery (A) and internal jugular vein (V). Quadrangles above the cross-sections illustrate the ultrasound images of the artery (A) and the vein (V). (A): Coronal approach, head facing anteriorly, representing conventional anatomic approach. (B): Cannulating needle approach, head turned to left, representing actual operating conditions, or "what the cannulating needle sees."