15-year Chronic Hepatitis B in Medicine / Internal Medicine — 55yo Man | Hepatology | SMLE Q#6147

A 55-year-old man with a 15-year history of chronic hepatitis B presents to the hepatology clinic for routine follow-up. He reports mild fatigue but no weight loss, abdominal pain, jaundice, or gastrointestinal bleeding. Physical examination shows no ascites or stigmata of advanced liver disease. Abdominal ultrasound reveals a mildly coarse liver texture and a solitary hepatic nodule measuring 3 × 3 cm in the right lobe. The hepatologist is concerned about hepatocellular carcinoma and wants the most definitive imaging test to establish the diagnosis and guide management. Which of the following is the most appropriate next step to definitively diagnose hepatocellular carcinoma in this patient?