Table 1 Radiological grading of stress fractures (Arendt et al13).
Radiology | Bone scan | MRI | ||
---|---|---|---|---|
Normal | Normal | Normal | Normal | |
Grade 1 | Normal | Poorly defined area of increased activity | Positive STIR image | |
Grade 2 | Normal | More intense but still poorly defined | Positive STIR plus positive T2 | |
Grade 3 | Discrete line (?), discrete periosteal reaction (?) | Sharply demarked area of increased activity focal or fusiform | Positive T1 and T2 but without definite cortical break | |
Grade 4 | Fracture or periosteal reaction | More intense transcortical localised uptake | Positive T1 and T2 fracture line |
MRI, magnetic resonance imaging; STIR, short T1 inversion recovery.