INCREASED SOFT-TISSUE BLOOD-FLOW IN PATIENTS WITH REFLEX SYMPATHETIC DYSTROPHY OF THE LOWER-EXTREMITY REVEALED BY POWER DOPPLER SONOGRAPHY

OBJECTIVE. We evaluated the ability of power Doppler sonography to sho w increased soft-tissue blood flow in patients with reflex sympathetic dystrophy of the lower extremity. SUBJECTS AND METHODS. Power Doppler sonography was performed in 30 patients with reflex sympathetic dystr ophy of the lower extremity and in 26 asymptomatic control subjects. T he bilateral power Doppler sonograms that were obtained of the soft ti ssues of the dorsum of the foot of each subject were grouped in pairs, and three sonologists who were unaware of clinical information indepe ndently reviewed the images. Images were evaluated for the amount of p ower Doppler signal shown on the following scale: 1 = no flow or minim al flow; 2 = mild Row; 3 = moderate flow; and 4 = marked Row. RESULTS. More power Doppler Row was seen in the patients with reflex sympathet ic dystrophy than in the control subjects (p < .005). In addition, sid e-to-side asymmetry of Row was seen in patients, but this trend was no t statistically significant (p < .20). Receiver operating characterist ic (ROC) analysis showed that combined flow and asymmetry were more re lated to reflex sympathetic dystrophy than either parameter alone (are a under the ROC curve: for flow, 0.748; for asymmetry, 0.566; for both , 0.799). We found that when the sum of power Doppler Row in both feet was greater than or equal to five, and asymmetry of flow was greater than or equal to one, the sensitivity of power Doppler sonography for reflex sympathetic dystrophy was 73% and the specificity was 92%. CONC LUSION. Patients with reflex sympathetic dystrophy of the lower extrem ity have increased power Doppler Row compared with asymptomatic contro l subjects. Patients may also exhibit more side-to-side asymmetry of f low than control subjects.