19th January 2024

A 35-year-old male presents to his GP with lower back pain and stiffness for the past 9 months.

A 35-year-old male presents to his GP with lower back pain and stiffness for the past 9 months. He has no history of trauma, and denies any numbness, tingling or weakness in the legs. His bowels and bladder function has remained normal. On examination, he had reduced spinal flexion. His past medical history is unremarkable, aside from an eye infection a few weeks ago.

 What is the most appropriate first-line investigation for this patient?

Select the SINGLE most appropriate option from the list below. Select ONE option only.