case_images: PMC3955861_01
case_images: A 29-year-old man with underlying chronic hepatitis B and an incidentally detected hepatic nodule. A, On T1-weighted gradient-echo imaging (TR/TE: 3.6/1.4), there was a subtle low signal intensity nodule (upper left, arrow). On gadoxetic acid-enhanced MR imaging, the nodule demonstrated early homogeneous intense enhancement (upper right), subtle peripheral washout during the portal venous phase (lower left), and ring-like peripheral enhancement with a central washout pattern on 20 minutes delayed hepatobiliary phase (lower right). B, Histopathology reported proliferating hepatocytes and bile ductules with fibrous septae on the border compatible with focal nodular hyperplasia.
case_images: iranjradiol-11-9269-g001.jpg
case_images: PMC3955861_01_iranjradiol-11-9269-g001.jpg
case_images: fig7727
case_images: On gadoxetic acid-enhanced MR imaging, the mass demonstrated early intense homogeneous enhancement and subtle peripheral washout during the portal venous phase and ring-like peripheral enhancement with a central washout during the equilibrium phase and hepatobiliary phase (20 minutes, Figure 1 A). Ultrasound-guided biopsy was performed, and the biopsy specimens were grossly visualized as yellowish gray soft tissue and proliferating bile ductules with fibrous stroma and normally proliferating hepatocytes (Figure 1 B), which was histopathologically indicative of FNH.
case_images: PMC3955861_02
case_images: A 39-year-old man with a history of heavy alcoholism. A, T2-weighted fast-spin echo imaging (TR/TE: 3646.3/107. 0, upper left, arrow), and diffusion weighted imaging (b-factor, 800, upper right) showed a high signal intensity nodule in the subcapsular portion of the right hepatic lobe. On T1-weighted gradient-echo imaging (TR/TE: 3.6/1.4), there was a high signal-intensity nodule with a peripheral halo (middle left). On gadoxetic acid-enhanced MR imaging, the nodule was visualized with early homogeneous enhancement (middle right), washout during the equilibrium phase (lower left), and complete perfusion defect on the 20 minutes delayed hepatobiliary phase (lower right). B, On histopathology (HE stain, high-power field [x200], a fibrous septum was observed in the tumor nodule exhibiting signs of lymphocytic infiltration. The hepatocytes formed one or two cell thick trabecular cords and were cytologically benign proliferating hepatocytes compatible with a diagnosis of focal nodular hyperplasia.
case_images: iranjradiol-11-9269-g002.jpg
case_images: PMC3955861_02_iranjradiol-11-9269-g002.jpg
case_images: fig7728
case_images: On gadoxetic acid-enhanced MR imaging, a well-defined, well-encapsulated, subtle high SI hepatic nodule was observed on T1-weighted imaging (T1WI) showing homogeneously intense enhancement during the early phase, subtle washout during the delayed phase and a low signal perfusion defect during the hepatobiliary phase (Figure 2 A). Ultrasound-guided biopsy was performed for confirmation, and the histopathologic reports showed hepatocellular nodule with fibrovascular septae favoring FNH (Figure 2 B).