目的 探讨单光子发射计算机断层显像（SPECT）/X线计算机断层显像(CT)在131I去除治疗分化型甲状腺癌（DTC）后的临床应用。方法 对119例接受甲状腺全切或部分切除术后的DTC患者（其中男性22例，女性97例），用131I去除残余甲状腺组织（简称去除治疗）5～7d后，行131I-SPECT 配2.5mA X射线球管装置和131I全身扫描（131I-WBS显像），所有结果均通过病理、其他影像检查(B超、CT)和临床随访一年确定DTC转移灶397处。结果 119例病人经131I-SPECT 配2.5mA X射线球管装置融合显像检查发现DTC转移或复发灶377处，占95%(377／397)，假阴性有9处，占2％(27／397)，假阳性病灶11处，占3％(11／397)。131I-WBS显像检查发现DTC转移灶或复发灶324处，占82%(324／397)，假阴性有64处 ，占16％(64／397)，假阳性病灶9处，占2％(9／397)。从病灶检出数目看，差异具有统计学意义（t=-8.445，P <0.01）。结论 131 I-SPECT配2.5mA X射线球管装置显像在131I去除治疗后能够精确定位DTC复发和转移，准确鉴别病灶和生理显像或污染的影响，提高DTC术后病灶的检出率，明确病灶的具体部位及摄碘情况，有助于对DTC进行再分期,为患者的进一步治疗提供临床依据。

Objective To explore the clinical application of single photon emission computed tomography (SPECT) / X-ray computed tomography (CT) imaging in patients of differentiated thyroid carcinoma (DTC) with 131I treatment after DTC removal. Methods 119 patients undergoing thyroid DTC patients with total or partial resection (Male 22 cases, female 97 cases) to remove residual thyroid tissue by 131I (referred to as the removal treatment) 5 ~ 7d, 131I-SPECT with 2.5mA X-ray tube device and 131I whole body scan (131I-WBS scan), all the results were confirmed by pathology, other imaging (B-mode ultrasonography , CT) and clinical follow-up one year to determine DTC 397 metastasis lesions. Results The total 377 of DTC metastasis or recurrence lesions were found in patients by 131I-SPECT with 2.5mA X-ray tube device fusion imaging, accounting for 95%. The false negative lesions were 9, accounted for 2%, and 11 false positive extra nodal lesions, accounting for 3%. 131I-WBS imaging found 324 DTC metastasis or recurrence lesions, accounting for 82%. The false negative lesions were 64, accounted for 16% and 9 false positive extra nodal lesions, accounting for 2%. There were significantly difference in founding lesions number between two methods (P <0.01). Conclusion 131 I-SPECT with 2.5mA X- ray tube device imaging in patients of differentiated thyroid carcinoma (DTC) with 131I treatment after DTC removal can accurately locate the recurrence and metastasis lesions of DTC and improve the detection rate of lesions. It would be helpful for re-staging of DTC and provide the basis for further treatment of patients.