In addition, although sacroiliitis is the primary axial feature in SpA, there is increasing evidence that there can also be spinal involvement even in the absence of SI joint inflammation. Recent studies suggest that spinal inflammation can occur in up to one-third of nonradiographic SpA patients with <5 years of disease duration.18 This could be an important early imaging inflammatory biomarker. To our knowledge there are no published studies evaluating spinal and SI joint MRI imaging biomarkers in Crohn's associated SpA.