Grading scales with definitions for FD and NV
| Grade | FD | NV |
|---|---|---|
| 0 | Normal | Normal (no signal) |
| 1 | Mild (involving under 25% of the height of the tendon) | Mild (single small signal in the ROI) |
| 2 | Moderate (involving 25–50% of the height of the tendon) | Moderate (Doppler activity in <25% of the ROI) |
| 3 | Severe (involving more than 50% of the height of the tendon) | Severe (Doppler activity in 25–50% of the ROI) |
| 4 | Partial rupture (disruption of the fibres in the full thickness of the tendon) | Extreme (Doppler activity in more than 50% of the ROI) |
FD, fibrillar disruption; NV, neovascularity; ROI, region of interest.