Objectives: 18F-fluoride uptake represents active osteoblastic bone synthesis. We assessed bone synthetic activity in inflammatory lesions and syndesmophytes in patients with ankylosing spondylitis (AS) using 18F-fluoride positron emission tomography-magnetic resonance imaging (PET-MRI, Philips Healthcare, Cleveland, OH, USA) and x-ray.
Methods: All images of 12 AS patients were recorded with the presence or absence of increased 18F-fluoride uptake lesions on PET, acute (type A) or advanced (type B) corner inflammatory lesions (CILs) on MRI, syndesmophytes on x-ray at the anterior vertebral corners.