Portal vein aneurysm is very rare, and its relation to portal hypertension has been emphasized. We report six cases of portal vein aneurysm (five extrahepatic and one intrahepatic). All patients were asymptomatic and had no signs suggestive of portal hypertension; the lesion was incidentally detected by ultrasound. Color Doppler sonography showed a constant hepatopetal flow along the aneurysmal wall, which immediately led to the diagnosis. We stress the usefulness of color Doppler sonography for studying the hemodynamics of this vascular anomaly and briefly review the literature.

Color Doppler sonography was very useful for the diagnosis of gastric and duodenal varices and for visualizing fine venous flows in the thickened gastric or duodenal wall. When it shows portal thrombosis in the confluence of the splenic vein and the superior mesenteric vein, duodenal varices should be suspected. The flow direction of the left gastric vein helps to differentiate hemorrhagic gastric varices from nonhemorrhagic ones.

Extrahepatic portosystemic shunt usually occurs secondary to severe portal hypertension, and it is rare to encounter it in patients without portal hypertension. We report herein a large extrahepatic portosystemic shunt between the left gastric vein and left renal vein without portal hypertension in which color Doppler sonography was useful not only for detection but evaluation of the effect of embolization.

Portal hypertension is a relatively uncommon pathologic condition in children and young adults in contrast with older adults. The aim of this study is to evaluate the utility of sonography and color Doppler sonography in the diagnosis of portal hypertension in children and young patients and to evaluate the sonographic pattern of each disease. We reviewed 25 such patients who were younger than 30 years old and obtained the following sonographic findings: (1) liver cirrhosis: (a) multiple intrahepatic venovenous shunts in patients with primary Budd-Chiari syndrome and (b) intrahepatic vascular narrowing and nodular coarse parenchymal texture, with multiple very-high-echo spots along the portal vein in patients with Wilson disease; (2) congenital hepatic fibrosis: marked and developed collaterals, wide periportal echogenic band, and a heterogeneous parenchymal texture comprised of multiple high echoes but without portal thrombus; and (3) extrahepatic portal thrombosis: invisible portal lumen except as an echogenic band. Sonography and color Doppler sonography are very useful in diagnosing these portal hypertensive diseases. However, there are no specific sonographic findings, and the role of sonography is limited to follow-up observation of associated secondary hepatobiliary changes in patients with congenital biliary atresia.

Pneumatosis cystoides intestinalis (PCI) is a relatively rare benign condition, and its sonographic findings have rarely been reported. We report on four cases of PCI in which sonography showed multiple immobile linear or spotty high echoes in the thickened colonic wall. These sonographic findings were more clearly visualized by using high-frequency probes and helped in establishing the diagnosis. In addition, color Doppler sonography confirmed the absence of portal gas and helped rule out fulminant PCI. When encountering patients with abundant abdominal gas, the possibility of PCI should be considered and the colonic wall and the portal vein should be meticulously observed by high-frequency probe and color Doppler sonography to prevent a delay in the diagnosis and to improve patient management.