The usefulness of quantitative evaluation of three-phase scintigraphy in the diagnosis of post-traumatic reflex sympathetic dystrophy.

Quantitative analysis of three-phase bone scintigrams was done in 70 patients with reflex sympathetic dystrophy (RSD) and in 30 patients who did not have RSD after injury to the hand or wrist. Regions of interest were selected and the uptake ratios (affected/unaffected) were calculated. Significant differences between affected and unaffected patients were seen in the metacarpal area in phase 2 of the scintigrams as well as in the metacarpophalangeal joints and metacarpal bones in phase 3. Combination of these images had the greatest diagnostic value. Sensitivity and specificity of 80% were achieved in the regions of interest in phase 3. The duration of RSD and the predisposing injury significantly affected the results of bone scintigraphy. It was also noted that a fracture may cause increased fixation of the tracer in each phase of three-phase bone scintigraphy in asymptomatic patients.