To explore the diagnosis of the ¹⁸F-FDG PET/CT and evaluate the feasibility of SUVmax in the differential diagnosis of benign and malignant thyroid nodules.

The diagnostic efficacy of PET/CT in differentiating benign and malignant thyroid nodules was retrospectively analyzed by calculating the sensitivity, specificity, accuracy, positive predictive value and negative predictive value in one hundred and one patients with thyroid who had ¹⁸F-FDG PET/CT before surgy, including thirty males and seventy-one females, age 17~78(48.2±12.9). The ROI of the contralateral nodules, the affected side of thyroid tissues or the surrounding tissues delineated, the SUVmax values were measured, SPSS software package was used to detect differences between the benign and the malignant lesions.

The sensitivity of ¹⁸F-FDG PET/CT examination for benign and malignant thyroid nodule was 89.1%; the specificity was 60.0%; the accuracy was 62.3%; negative predictive value was 35.2% and positive predictive value was 90.1%.SUVmax value was statistically significant between the two groups of benign and malignant thyroid (t=3.14, P<0.05). The SUXmax in malignant group [6.70±4.57(1.3~21.7)] was higher than that in the benign group[3.95±2.58(1.3~12)].

It is meaningful for the ¹⁸F-FDG PET/CT in identification of benign and malignant thyroid nodules.And it is feasible to distinguish between the benign and malignant nodules with reference to the SUVmax value.