Supplementary Material for: MRI USING GADOXETIC ACID IN THE WORK-UP OF LIVER NODULES NOT CONCLUSIVELY BENIGN IN BUDD-CHIARI SYNDROME. A PROSPECTIVE LONG-TERM FOLLOW-UP

Introduction The incidence of hepatocellular carcinoma (HCC) in Budd-Chiari syndrome (BCS) is unknown and there is no validated diagnostic work-up to define the liver nodules with arterial phase hyperenhancement (APHE) suggesting malignancy. This prospective study evaluates HCC incidence in a Western cohort of patients with BCS and assesses the performance of MRI with hepatobiliary contrast (HB-MRI) for nodule characterization. Methods Patients with BCS followed in our hospital were prospectively evaluated by MRI with extracellular contrast (EC-MRI). Nodules with APHE categorized as non-conclusively benign by 2 radiologists, were studied by HB-MRI and reviewed by 2 radiologists blinded to the EC-MRI results. A new EC-MRI one year later and clinical, analytical and sonographic follow-up every six months for a median of 10 years were performed. Results A total of 55 non-conclusively benign nodules with APHE were detected at EC-MRI in 41 patients. While 32 of them were suggestive of HCC by EC-MRI, all the 55 nodules showed increased uptake of hepatobiliary contrast. An unequivocal central scar was seen in 12/55 nodules at HB-MRI regardless of it was not detected on the EC-MRI. None of the nodules was hypointense in the hepatobiliary phase. HCC was not detected during a median of 10 years of follow-up. Conclusions Detection of nodules with APHE is frequent in patients with BCS, but HCC is rare in Western patients with BCS. While EC-MRI may detect nodules suggesting malignancy, the identification of contrast uptake in the hepatobiliary phase at HB-MRI may help to categorize them as benign.