Magnetic resonance imaging findings in cases of hepatobiliary fascioliasis

Fascioliasis is a foodborne parasitic disease caused by Fasciola hepatica and Fasciola gigantica. Epidemiological studies on humans have revealed that it has a wide distribution worldwide. Fascioliasis has two distinct phases, hepatic and biliary, and clinical status and radiological findings vary according to the phase. Especially in regions where it is not endemic, misdiagnoses or delays in diagnosis may be seen due to radiologic confusion with many different pathologies, and therefore unnecessary investigations and invasive procedures may be performed. There are limited number of studies in the literature describing magnetic resonance imaging (MRI) findings of fasciolosis. The aim of this study was to describe in detail the MRI findings of hepatobiliary fasciolosis at the time of initial diagnosis, to investigate the segmental distribution of the areas of involvement in the liver and to analyse the relationship between MRI findings and laboratory findings. The study was carried out by analysing the dynamic liver MRI and/or magnetic resonance cholangiopancreatography (MRCP) images and laboratory findings of a total of 69 patients, 63 in the hepatic phase and 6 in the biliary phase, who were diagnosed with 'Hepatobiliary Fascioliasis' at Fırat University Medical Faculty Hospital between 2011-2023. Of the patients in the study, 42 (60.9%) were female and 27 (39.1%) were male, and 6 (8.7%) were children (<18 years). Of the 63 cases in the hepatic group, 93.7% had tubular structure, 73% had clustering nodules, 47.6% had cyst-cystic degeneration, 3.2% had T1 hyperintense cysts, 36.5% had increased signal in the capsule on T2A, 12%, Contrast enhancement in the capsule was found in 7%, Transient hepatic attenuation differences was found in 42.9% and hypointensity in the hepatobiliary phase was found in all 23 patients (100%) in whom hepatocyte specific agent was used as contrast agent. When the segmental distribution of the areas of involvement in the liver was analysed, the most frequently involved segments were segments 5 and 8 with 68.3%, followed by segment 7 with 66.7% and segment 6 with 61.9%. There was isolated segment 1 involvement in 1 (1.6%), isolated left lobe involvement in 1 (1.6%), isolated right lobe involvement in 29 (46%) and both lobes involvement in 32 (50.8%) cases. There was a positive correlation (p<0.05) between the number of segments involved in the liver and the percentage of eosinophils, ALP, GGT, LDH and CRP values. In the evaluation of diffusion-weighted images, ADC values obtained from lesion areas were lower than normal parenchyma (p<0.01), while ADC values of cyst-cystic degenerations were higher than normal parenchyma (p<0.01). Of the 6 cases in the biliary phase, 4 (66.7%) had dilatation in the intrahepatic bile ducts, 6 (100%) had dilatation in the extrahepatic bile ducts and hypointense appearances in the biliary system, 3 (50%) had wall thickening in the biliary system and 1 (16.7%) had pancreatitis and cholecystitis. In addition, 3 of 4 patients (75%) who underwent dynamic liver MRI showed wall contrast enhancement in the biliary system. In the hepatic phase, hepatomegaly was detected in 26.9%, splenomegaly in 15.9%, periportal LAPs in 49.2%, pleural effusion in 13.8%, pulmonary consolidation in 1.6%, ectopic involvement in 4.8% and ascites in 1.6%. No hepatomegaly or extrahepatic findings were observed in the biliary phase. In this study, MRI findings of hepatobiliary fascioliasis in hepatic and biliary phases were described in detail. Hepatobiliary fascioliasis has typical MRI findings and knowing them will contribute to prevent misdiagnosis and reduce unnecessary examinations and invasive procedures. Key Words: Fasciola hepatica, fascioliasis, magnetic resonance imaging, liver