A 12-year-old child presents with acute abdominal pain that…
A 12-year-old child presents with acute abdominal pain that began diffusely and has migrated to the right lower quadrant over the past 8 hours. The child has nausea, anorexia, and a temperature of 100.8°F (38.2°C). Physical examination reveals rebound tenderness and voluntary guarding. Laboratory results show leukocytosis and elevated C-reactive protein. Which of the following is the most appropriate initial diagnostic imaging to confirm the suspected diagnosis?