Diagnostic value of ultrasonography for post-liver transplant hepatic vein complications

Figure 1 Normal hepatic veins. A: Color Doppler imaging shows the right hepatic vein (blue arrow) and the middle hepatic vein (red arrow) draining into the inferior vena cava. Both the right and middle hepatic veins can be visualized simultaneously below the right costal margin. The left hepatic vein is difficult to display in the same plane due to its angle; B: Spectral Doppler imaging shows waveforms of the right hepatic vein. Post-liver transplantation, normal hepatic vein waveforms can appear triphasic, biphasic, or even monophasic. Greater variability in the amplitude of hepatic vein waveforms suggests fewer hepatic vein abnormalities. Blood flow velocity also varies significantly, influenced by the measurement location, patient respiration, and the degree of hepatic vein filling.