PATTERN-RECOGNITION IN 5-PHASE BONE-SCINTIGRAPHY - DIAGNOSTIC PATTERNS OF REFLEX SYMPATHETIC DYSTROPHY IN ADULTS

The objective of this study was to assess qualitative and quantitative patterns of tracer accumulation to increase the diagnostic utility of bone scintigraphy in reflex sympathetic dystrophy (RSD), Of 120 patie nts with high clinical suspicion for RSD, 96 were confirmed as having RSD during follow-up, while the remaining 24 were used as controls. Cl inical parameters were measured and correlated to five activity ratios (0-30 s, 0.5-5 min, 5-15 min, 3 h, 24 h) and five scintigraphic signs . Monitoring three dynamic phases revealed different tracer kinetics o f potential diagnostic utility; however, the 24-h bone phase offered n o additional diagnostic contribution and can be omitted. Quantificatio n provided objective parameters for the duration of symptoms, pain and impairment of movement but not for surface temperature differences, s welling and impairment of physical force, It is of limited use for dia gnosis except for the exclusion of disease. Discriminant analysis reve aled the combination of three signs (diffuse uptake in carpus/tarsus+d iffuse uptake in all small joints+increased activity ratio in the late blood pool phase) to be the pattern with the highest diagnostic accur acy independent of localisation, sex, age and precipitating factors. I t is concluded that the scintigraphic confirmation of RSD is based on lateralisation in the late blood pool phase and the described pattern in the early bone phase.