For suspected ankylosing spondylitis, which imaging investigation is essential?

In the context of suspected ankylosing spondylitis, spinal X-rays are essential as they are a key tool in the initial assessment and diagnosis of this condition. Spinal X-rays can reveal characteristic changes in the sacroiliac joints and spine that are associated with ankylosing spondylitis, such as syndesmophytes and calcification, which are essential for confirming the diagnosis.

Early X-ray findings may include the blurring of the sacroiliac joints, and in some cases, these changes can be quite subtle, necessitating a skilled interpretation. While MRI can provide more detailed images and may be used in later stages or when X-ray findings are inconclusive, spinal X-rays remain the cornerstone for initial evaluation due to their availability, cost-effectiveness, and ability to visualize bony changes.

Other imaging modalities, like CT scans or MRIs of non-spinal regions, do not contribute significantly to the diagnosis of ankylosing spondylitis, while ultrasound of the spine is not standard practice for this diagnosis. Spinal X-rays serve as the foundation for evaluating structural changes in the spine, reinforcing their essential role in the diagnostic process.