Which imaging finding is consistent with Schistosomiasis?

Increased echogenicity and thickening of the portal vein is a hallmark imaging finding associated with Schistosomiasis. This parasitic infection can lead to chronic portal hypertension due to the presence of eggs in the portal circulation, causing inflammatory responses and fibrosis in and around the portal vein. As this condition progresses, the normal structure of the portal vein becomes altered, resulting in both thickening of its walls and increased echogenicity on ultrasound due to the deposition of fibrous tissue.

The other findings, while they may be associated with other conditions affecting the liver or spleen, are not specific to Schistosomiasis. For example, increased echogenicity of the gallbladder could suggest other gallbladder diseases, and hypoechoic liver lesions may indicate various neoplastic or infectious processes unrelated to this infection. Enlargement of the spleen, known as splenomegaly, can occur in a variety of conditions, including portal hypertension from other causes, but is not uniquely indicative of Schistosomiasis. Thus, the thickening and increased echogenicity of the portal vein is the most relevant finding in this context.