The relationship between the SUV max value and the maximum thymoma diameter. The sensitivity, specificity, and accuracy of 18F-FDG in the detection of low-grade thymomas and thymomas with a maximum diameter of ≤50 mm and an SUV max of ≤3.4 were 85%, 48%, and 60%, respectively. SUV max: maximum standardized uptake values; 18F-FDG: 18F-fluorodeoxyglucose