The predictive value of additional late blood pool imaging to the three-phase bone scan in the diagnosis of reflex sympathetic dystrophy in hemiplegic patients

Reflex sympathetic dystrophy (RSD) is a relative common sequel after hemiplegia. The diagnosis of RSD in hemiplegic patients presents difficult clinical problems, as the symptoms and signs of RSD are not specific and RSD may be due to reasons other than hemiplegia. Bone scintigraphy has been routinely used for the diagnosis of RSD; however, the optimal acquisition protocols, diagnostic patterns and the utility of quantitation are controversial. This prospective study was conducted to demonstrate the higher predictive value of an additional late blood pool image to the three-phase bone scan compared to the regular three-phase bone scans in RSD patients associated with hemiplegia. Thirty-four RSD patients were enrolled into the study. Bone scans according to the new protocol were obtained for all patients. Those patients with either negative or positive bone scans with no evidence of RSD were followed for 6 months. The patients had positive bone scan findings and were symptomatic at the time of the study. Of these, seven patients (58.3%) subsequently became symptomatic and five patients (41.7%) remained asymptomatic at 6 months. None of the patients with negative bone scans had symptoms of RSD on presentation except one case. We conclude that the addition of a late blood pool image increases the predictive value and has an impact on initiating early treatment in asymptomatic patients.