Fig. 6From: Ultrasound-guided cannulation of hemodialysis accessAcoustic shadow-tracing method. If the probe is scanned to-and-fro down the course of the femoral vein, and the trajectory of the shaft image (dotted arrow) is directed to the center of the femoral vein, the direction of the needle is correct (left). Otherwise (right), redirection of the needle is necessary. A: femoral artery V: femoral veinBack to article page