Fig. 6From: Common pitfalls in point-of-care ultrasound: a practical guide for emergency and critical care physicians a Rouleaux formation over the venous valves (arrows). b After distal compression, the blood was squeezed and the rouleaux are finally cleared. Arrows venous valves. c Normal phasic venous waveform, indicating a non-stopping flow between the heart and the site of insonation. d Abnormal non-phasic venous flow, indicating a stop between the heart and the site of insonationBack to article page