Fascioliasis: US, CT, and MRI findings with new observations

Background: The purpose of this study is to describe the ultrasonographic ( US), computed tomographic (CT), and magnetic resonance imaging (MRI) findin gs in fascioliasis and to emphasize the impact of radiology in diagnosis. Methods: Radiologic findings in 23 consecutive patients with fascioliasis w ere prospectively recorded. All patients had at least one US and CT examina tion, and 10 of them were studied by MRT. All diagnoses were confirmed by s erologic methods. In the first three cases, initial diagnosis was reached b y microscopic demonstration of the parasites' eggs in bile obtained by US-g uided gallbladder aspiration. Results: In the hepatic phase of fascioliasis, multiple, confluent, linear, tractlike, hypodense, nonenhancing hepatic lesions were detected by CT. On US, the parasites could be clearly identified in the gallbladder or common bile duct as floating and nonshadowing echogenic particles. MRI showed the lesions as hypo- or isointense on T1-weighted images and as hyperintense o n T2-weighted images. Conclusions: CT findings in the hepatic phase and US findings in the biliar y phase are characteristic of fascioliasis. Because clinical and laboratory findings of fascioliasis may easily be confused with several diseases, rad iologists should be familiar with the specific radiologic findings of the d isease to shorten the usual long-lasting diagnostic process.