MRCP2-2055
A 38-year-old female presents with subacute onset, itching, severe abdominal pain and distension. The patient has a history of hypothyroidism and borderline type 2 diabetes. She occasionally experiences lower back pain following long days standing at work as a waiter. Her current medications include Levothyroxine, Metformin, combined oral contraceptive pill, Paracetamol, and Ibuprofen. On examination, the patient has obvious pain, yellowing of the sclera, and tender hepatomegaly with shifting dullness. Blood investigations reveal elevated levels of Total Bilirubin, ALT, and ALP. Which investigation is most appropriate to confirm the likely diagnosis?