How Is Non-Radiographic Axial Spondyloarthritis (nr-axSpA) Different from Ankylosing Spondylitis (AS)?

Nr-axSpA and AS are similar and are on the same spectrum of spine-related arthritis. The main difference is that in nr-axSpA, the sacroiliac joints (where the spine meets the pelvis) don’t show definitive damage on X-rays, which is often seen in AS.