Biliary Peritonitis after Radiofrequency Ablation Diagnosed by Gadoxetic Acid-Enhanced MR Imaging
An 80-year-old female with liver cirrhosis from hepatitis C was presented to our hospital with elevated serum alpha-fetoprotein. Liver dynamic CT consisting of two phases was performed with a four-channel multi-detector row CT (LightSpeed QX/i; General Electric Medical Systems, Milwaukee, WI, USA). Two-phasic scanning was started with a 35-delay for the arterial phase, and a 90-second delay for the portal venous phase, after the beginning of contrast medium injection. The patient had a hepatic mass in segment VIII, which showed marked enhancement in the arterial phase and low attenuation compared to liver parenchyma in the portal venous phase, which was diagnosed as typical hepatocellular carcinoma (). RFA was the most appropriate treatment as opposed to surgery, and was performed using three bipolar RF electrodes (CelonPOWER system; OLYMPUS Winter & Ibe GmbH, OLYMPUS, Japan) with a 30-mm exposed tip. Contrast-enhanced CT in the portal venous phase obtained seven days after RFA revealed an ablated tumor with sufficient margin (). The patient had a good course and was discharged two weeks after RFA therapy.\nTwo months later, the patient had sudden upper abdominal pain, and underwent a dynamic contrast-enhanced CT scan. The scan demonstrated marked enhancement on the surface of the liver, fluid collection around the liver, and dirty omentum. Biliary peritonitis was suspected. The next day, MR imaging with Gd-EOB-DTPA (Primovist, Bayer-Schering, Berlin, Germany) was performed to evaluate biliary leakage from the liver.\nMRI examination was performed with a 1.5-T clinical unit (Signa EXCITE EchoSpeed Plus; General Electric Medical Systems, Milwaukee, WI, USA) using a TORSO coil. Liver Acquisition with Volume Acceleration sequence was used with the following parameters: TR/TE/FA: 5.3 ms/2.3 ms/12°, 4.6-mm thickness without gap, and 320 × 192 matrix. A bolus of 0.025 mmol/kg body weight Gd-EOB-DTPA was injected intravenously by a power injector at a rate of 1 mL/s. Enhanced T1-weighted images were acquired 20, 60, and 300 minutes after the administration of Gd-EOB-DTPA (). Enhanced T1-weighted MR imaging acquired at 300 minutes showed increased signal intensity in the fluid collection around the liver than in the image acquired at 20 minutes. Linear high signal areas to match the RFA puncture route were also demonstrated, suggesting a biliary leakage route from the bile duct to the fluid collection around the liver. Biliary peritonitis was diagnosed. Percutaneous drainage for fluid collection around the liver was performed, and the collected fluid was confirmed as bile.