目的 对18F-FDG PET/CT检查发现可疑甲状腺高代谢结节的发病率和良恶性进行回顾性分析。方法 回顾2010年11月至2013年5月间行18F-FDG PET/CT检查，发现甲状腺病变的2569例患者中，甲状腺呈高代谢灶的患者1219例，有病理证实及随访结果的 67例。根据病变病理及随访结果，结合代谢情况、影像表现，对此67例甲状腺良恶性病变发病率进行分析。结果 甲状腺弥漫性病变恶性率与局灶性高代谢病变恶性率的差异有统计学意义（P<0.01）。单发高代谢结节中，恶性结节及良性结节SUVmax值分别为6.63±4.49和3.07±1.42，两者之间差异有统计学意义（t＝2.436，P＝0.035）。多发结节单发高代谢灶病变中，恶性及良性病变SUVmax值分别为5.72±2.47和3.37±0.74，两者之间差异无统计学意义。多发高代谢结节的良恶性SUVmax值差异无统计学意义（t=1.870，P=0.151）。结论 甲状腺高代谢结节有较高的恶性率，SUVmax值对单发高代谢结节的良恶性鉴别有意义。

Objective To investigate the prevalence of the suspicious primary thyroid disease incidentally detected by 18F-FDG PET/CT and to explore the diagnostic value between malignant and benign thyroid disease. Methods During November 2010 to May 2013, 2569 patients were suspected primary thyroid disease via 18F-FDG PET/CT scan．Among them, 1219 patients were proved hyper-metabolic lesions. Sixty-seven patients were conformed via histopathology or clinical follow-up. Then, these patients were analyzed with metabolism, PET and CT imaging to reveal the characteristic features between malignant and benign. Results Malignant rate of hypermetabolic thyroid nodules was significantly different from that of diffuse hypermetabolic thyroid （P<0.01）. The SUVmax value of malignant and benign for the patients with single hypermetabolic thyroid nodule were 6.63±4.49 and 3.07±1.42, respectively (t=2.436，P=0.035). The SUVmax value of malignant and benign for the patients with multiple nodules single hypermetablic focus were 5.72±2.47 and 3.37±0.74, respectively (t=1.870，P=0.151). No statistics difference of SUVmax value was found between malignant group and benign group with multiple hypermetabolic thyroid nodules. Conclusion Focal hypermetabolic thyroid nodules detected via 18F-FDG PET/CT come with high malignant rate. Differential diagnosis between malignance and benign can be conducted by the SUVmax value.