NephroPOCUS

#POCUS answer: Jugular vein The point of this quiz is to highlight that not everything that looks pulsatile is an artery! Color Doppler flow can be red in a vein, and spectral Doppler flow can appear above the baseline. It all depends on the direction of blood flow relative to the transducer, not whether the vessel is an artery or a vein. It's also about learning to distinguish venous from arterial flow - when a simultaneous ECG is available, it is a great clue. Here, you can see fusion of the systolic and diastolic flow components rather than a distinct high-velocity systolic peak followed by lower-velocity diastolic flow, as typically seen in carotid artery. I'm also attaching an arterial Doppler tracing from the same patient for comparison. Again, pay attention to the timing in relation to the ECG. Fusion of systolic and diastolic components (S and D-waves) is not uncommon, especially in hyperdynamic states, and is not necessarily abnormal by itself. Another point: Here, the artery doesn't appear simply red or blue on color Doppler. Instead, you see a mixture of colors due to aliasing because the color Doppler velocity scale is set much lower than the actual blood flow velocity in the artery.