30th April 2024

A 39-year-old woman presents with sudden onset of severe upper abdominal pain that radiates to her back.

A 39-year-old woman presents with sudden onset of severe upper abdominal pain that radiates to her back. She describes the pain as constant and worsening over the past 24 hours. She also reports nausea but no vomiting. She has a history of hypertriglyceridemia but does not consume alcohol. On examination, her abdomen is tender in the epigastric region, but there’s no rebound tenderness or guarding. She is afebrile and her blood pressure is 130/85 mmHg. Initial laboratory tests show a normal white blood cell count and slightly elevated liver enzymes.

Which of the following is the most appropriate initial test to confirm the diagnosis?