Table 5.
Sensitivity and specificity of US, x-ray, and clinical examination, with MRI as the standard reference method
| US sensitivity | US specificity | X-ray sensitivity | X-ray specificity | Clinical examination sensitivity | Clinical examination specificity | |
| Bone erosions | ||||||
| MCP joint | 0.56 | 0.93 | 0.38 | 0.99 | NA | NA |
| PIP joint | 0.57 | 0.88 | 0.40 | 0.95 | NA | NA |
| DIP joint | 0.00 | 0.99 | 0.67 | 0.97 | NA | NA |
| Bone proliferations | ||||||
| MCP joint | 0.00 | 0.97 | 0.00 | 0.96 | NA | NA |
| PIP joint | 0.50 | 0.96 | 0.00 | 0.96 | NA | NA |
| DIP joint | 1.00 | 0.95 | 1.00 | 0.98 | NA | NA |
| Synovitis | ||||||
| MCP joint | 0.70 | 0.88 | NA | NA | 0.31 | 0.74 |
| PIP joint | 0.50 | 0.88 | NA | NA | 0.25 | 0.76 |
| DIP joint | 0.40 | 0.87 | NA | NA | 0.00 | 0.83 |
| Tenosynovitis | ||||||
| MCP joint | 0.38 | 0.99 | NA | NA | NA | NA |
| PIP joint | 1.00 | 0.86 | NA | NA | NA | NA |
| DIP joint | 0.67 | 0.98 | NA | NA | NA | NA |
| Insertional changes | ||||||
| Extensor tendons | 0.50 | 0.96 | NA | NA | NA | NA |
| Flexor tendons | 1.00 | 0.95 | NA | NA | NA | NA |
| Capsular/extracapsular changes | 1.00 | 0.88 | NA | NA | NA | NA |
The imaging modalities were ultrasonography (US), magnetic resonance imaging (MRI), projection radiography (x-ray), and clinical examination. DIP, distal interphalangeal; MCP, metacarpophalangeal; NA, not applicable; PIP, proximal interphalangeal.