Secondary causes of Budd-Chiari Syndrome include compression or mechanical obstruction of the hepatic veins from a neoplasm (hepatocellular, adrenal, and renal cell carcinoma), an abscess, or hydatid
Secondary causes of Budd-Chiari Syndrome include compression or mechanical obstruction of the hepatic veins from a neoplasm (hepatocellular, adrenal, and renal cell carcinoma), an abscess, or hydatid cyst.
At sonography in the acute setting, a thrombus may be visible in the hepatic veins and may be obstructive or non-obstructive (figure 5). Again, it is important to examine the hepatic veins initially with gray scale sonography. Stenoses may also be observed, but typically, no collateral vessels are seen. When chronic, the hepatic veins may not be visualized and multiple intrahepatic collateral vessels may be seen (between a patent and an occluded hepatic vein, or between an occluded vein and a tortuous, developed collateral). Subcapsular and extrahepatic collaterals can also develop in the setting of chronic Budd-Chiari syndrome. It is also important to examine the caudate lobe of the liver, which frequently has enlarged veins that drain directly to the inferior vena cava in an attempt to decompress the liver. At color Doppler, there may be no detectable flow within the hepatic vein, or reversed flow when a proximal obstruction is present. The waveform is also monophasic.