Ultrasonography observations of entheses in patients with ankylosing spondylitis (AS). Values are expressed as number (%). Type A.: no abnormal findings in both B mode and color Doppler (CD) ultrasonography; B: swelling and/or decreased echogenicity, and/or calcification of tendon insertions and/or proliferation of periosteum. No CD signals were found in entheses; C: CD signals found in entheses with or without abnormal findings in B mode.
| Type | Active AS | Inactive AS |
|---|---|---|
| A | 912 (80.7) | 436 (90.8) |
| B | 117 (10.3) | 42 (8.8) |
| C | 101 (8.9) | 2 (0.4) |