The normal flow of the renal vein at the hilum is:

• A. Pulsatile
• B. Non-pulsatile
• C. Highly pulsatile
• D. Reversed

Answer: (B)

Venous flow is non-pulsatile because veins are low-pressure, capacitance vessels that return blood to the heart with a steady, continuous velocity. In Doppler imaging at the renal hilum, this appears as continuous, low-velocity flow toward the heart with only minor variations from respiration, not the distinct pulsations seen in arteries. Pulsatile flow would reflect arterial systole and is not expected in a vein, while highly pulsatile or reversed flow would indicate abnormal or pathologic conditions. So the normal renal vein flow pattern is non-pulsatile.