A Point-Scoring System for the Clinical Diagnosis of Sjögren's Syndrome Based on Quantified SPECT Imaging of Salivary Gland

OBJECTIVE: To establish a point-scoring diagnostic system for Sjögren's syndrome (SS) based on quantified SPECT imaging of salivary gland, and evaluate its feasibility and performance compared with 2002 AECG criteria and 2012 ACR criteria. METHODS: 213 patients with suspected SS enrolled in this study. The related clinical data of all patients were collected. All patients were evaluated and grouped on a clinical basis and posttreatment follow-up by rheumatology specialists as the unified standard (SS group with 149 cases and nSS group with 64 cases). From SPECT imaging of salivary gland, T(max), UI(max), T(s) and EF(s) were derived for bilateral parotid and submandibular glands, and compared between the groups. A point-scoring diagnostic system for SS was established based on the quantified SPECT imaging of salivary gland. We estimated the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for the new diagnostic system, compared with 2002 AECG criteria and 2012 ACR criteria. RESULTS: When 7.0 was used as the cut-off point, the sensitivity, specificity, PPV, NPV and accuracy for the new point-scoring system in diagnosing SS were 89.93% (134/149), 93.75% (60/64), 97.10% (134/138), 80.00% (60/75) and 91.08% (194/213), respectively. The new point-scoring diagnostic system based on quantified SPECT imaging of salivary gland keeps the specificity comparatively to 2002 AECG criteria and 2012 ACR criteria, but improves the sensitivity significantly (P<0.01). CONCLUSION: The new point-scoring diagnostic system for SS based on quantified SPECT imaging of salivary gland may be superior to 2002 AECG criteria and 2012 ACR criteria, with higher sensitivity and similar specificity in the diagnosis of SS. Additionally, it also has good feasibility in the clinical settings.