Fig. 2From: Performance of 18F-sodium fluoride positron emission tomography with computed tomography to assess inflammatory and structural sacroiliitis on magnetic resonance imaging and computed tomography, respectively, in axial spondyloarthritisTwo examples of discordance between PET/CT and CT scan. A negative PET/CT with structural sacroiliitis on CT scan and multiple erosions (a), and a positive PET/CT without structural lesions (erosion or ankylosis) on CT scan (b)Back to article page