Friday, June 12, 2009

Normal Hepatic Artery Velocity in Portal Vein Thrombosis

Hepatic artery (HA) velocity is increased with portal vein thrombosis (PVT). This is responsible for the increased arterial-phase enhancement of the liver parenchyma supplied by the thrombosed veins.

In this image we see an enlarged hepatic artery (red) anterior to a thrombosed portal vein.

Normal values for HA peak velocities are hard to come by. Normal subjects in one study had mean HA velocities of less than 0.7 m/s. In this image (same patient as the first image) we see that the hepatic artery peak systolic velocity is greater than 2.5 m/s.

It has also been shown that HA resistance decreases with acute portal vein thrombosis. Control subjects in one study had mean HA resistive indices (HARI) of 0.75 +/- 0.08, while those with PVT had HARIs of 0.57 +/- 0.11. The reduction in HARI may not be as apparent with more chronic PVT.

References

  • Platt et al. Hepatic artery resistance changes in portal vein thrombosis. Radiology 1995; 196 (1): 95-98.
  • Rokni-Yazdi H and Sotoudeh H. Assessment of Normal Doppler Parameters of Portal Vein and Hepatic Artery in 37 Healthy Iranian Volunteers. Iran J Radiol, 2006; 3(4): 213-216

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