Fig. 30.

a Under normal conditions, the IRVD exhibits a continuous pattern with minimal pulsatility and no interruptions. b However, mild to moderate venous congestion results in heightened pulsatility and interruptions in the waveform, characterized by distinct systolic (S) and diastolic (D) waves. c In severe congestion, S-reversal occurs similarly to that of the HV, leaving only the D-wave below the baseline. IRVD, intrarenal vein Doppler; HV, hepatic vein; IRA, intrarenal artery; IRV, intrarenal vein