Quantitative methods of tophus measurement.
| Method | Category | Original Study |
|---|---|---|
| Counting the total number of subcutaneous tophi | Simple | Becker8 |
| Tape measurement of subcutaneous tophus area | Simple | Schumacher11 |
| Vernier calipers for measurement of subcutaneous tophus diameter | Simple | Perez-Ruiz12 |
| Digital photography for measurement of subcutaneous tophus area | Complex | Maroli13 |
| Ultrasonography for measurement of tophus diameter and volume | Complex | Perez-Ruiz14 |
| Magnetic resonance imaging for measurement of tophus volume | Complex | Schumacher15 |
| Conventional computed tomography (CT) for measurement of tophus volume | Complex | Dalbeth16 |
| Dual energy CT for measurement of tophus volume | Complex | Choi17 |