99Tcm-MDP blood-pool phase in the assessment of repetitive strain injury.

We reviewed three-phase bone scans of the limbs of 7 patients suffering from limb pain suggestive of occupational repetitive strain injury (RSI) and compared them with 13 patients with limb pain due to various aetiologies. Doppler ultrasound measurement of blood flow had been performed in 13 of the 20 patients. The bone scan results showed increased blood flow and pooling (second phase) in the affected limbs of patients with RSI as compared to those with algodystrophy or non-specific limb pain (sensitivity 86%, specificity 85%). Doppler ultrasound also demonstrated increased blood flow to the affected limbs (sensitivity 83%) but failed to differentiate between the different aetiologies of pain (specificity 14%). We conclude that the blood-pool phase of three-phase bone scans can play a potential role in screening RSI patients.