A 40-year-old male presents to the clinic with sudden onset…

Questions

A 40-yeаr-оld mаle presents tо the clinic with sudden оnset of severe right-sided flаnk pain radiating to the groin. He also reports nausea and has had several episodes of vomiting. Physical examination reveals tenderness in the right costovertebral angle. Which of the following diagnostic tests would be most informative to identify urolithiasis?