Comparison of the diagnostic performances of two protocols of hand perfusion scintigraphy for Raynaud’s phenomenon

Abstract

The aim of this study was to compare the diagnostic performances of two hand perfusion scintigraphy protocols for diagnosing Raynaud's phenomenon (RP). We enrolled 130 patients who underwent hand perfusion scintigraphy for suspected RP and 40 normal controls. Of these, 66 patients (group A) and 25 normal controls underwent 99mTc-methylene diphosphonate hand perfusion scintigraphy without one-hand chilling, and the finger-to-palm ratio (FPR) was calculated. The remaining 64 patients (group B) and 15 normal controls underwent 99mTc-methylene diphosphonate hand perfusion scintigraphy with one-hand chilling, and three parameters (the chilled-to-ambient hand ratios of the first peak height, initial slope, and blood pool uptake) were calculated. Forty-eight and 47 patients were clinically diagnosed with RP in groups A and B, respectively. In group A, patients with RP had significantly lower FPRs compared with those without RP, and the receiver operating characteristic curve analysis showed that an FPR of 0.51 was the best cutoff value for diagnosing RP, with a sensitivity of 63% and a specificity of 83%. In group B, the three aforementioned parameters differed significantly (lower or higher) between patients with and without RP. The receiver operating characteristic curve analysis provided highly sensitive and specific results for all three parameters. The initial slope ratio showed the highest sensitivity of 87% and a specificity of 88% when using cutoff values of 0.78 and 1.25. Although both protocols for hand perfusion scintigraphy showed high specificity for diagnosing RP, the protocol with one-hand chilling showed higher diagnostic ability compared with that without one-hand chilling.