MRCP2-4602

A 50-year-old female presents with severe lower back pain. She reports that the pain began a few months ago and has progressively worsened. She has also been experiencing weight loss, fevers, and rigors. Upon examination, there is severe tenderness upon palpation over the L4 vertebrae, but no associated neurological signs are present.

The following blood results were obtained:

– Hb: 105 g/l
– Platelets: 542 * 109/l
– WBC: 20.2 * 109/l
– Neuts: 15.4 * 109/l
– Lymphs: 2.2 * 109/l
– Na+: 140 mmol/l
– K+: 3.8 mmol/l
– Urea: 8.5 mmol/l
– Creatinine: 92 µmol/l
– CRP: 288 mg/l

What diagnostic test is most likely to confirm the diagnosis?