甲状腺疾病影像学检查方法及临床应用

甲状腺非侵入性检查手段包括超声、核素显像(单光子显像和正电子断层显像)、CT以及MRI.超声是一种无损伤、操作简便、价格低廉的检查方法,因而是甲状腺疾病尤其是甲状腺结节的首选影像检查方法,彩色多普勒血流成像(CDFI)和超声指导下的细针穿刺活检的应用,为甲状腺结节良、恶性的鉴别诊断提供了可能.核素显像(包括SPECT和PET)是一种功能显像.99mTcO4-是最常用的功能显像剂,131I主要用于分化型甲状腺癌.FDG PET一般不用于甲状腺疾病术前,但甲状腺癌术后考虑转移而131I扫描结果阴性时,可以考虑应用.临床上,CT常作为甲状腺疾病的第二线影像学检查方法.MRI技术本身有许多特点,但在甲状腺疾病而言,并不比CT优越.

Diagnostic imaging and clinical application in thyroid diseases

Several noninvasive imaging modalities including ultrasound, emission computed tomography (both SPECT and PET) ,CT and MRI have been used in the diagnosis of patients with thyroid diseases. Ultrasound is an easily available and relatively inexpensive modality with a high degree of accuracy and is routinely used for detection of thyroid nodule,and also for screening patients at high risk for thyroid cancer to detect clinically nonpalpable nodules. Color Doppler flow imaging(CDFI) and fine needle aspiration biopsies (FNAB) guided by ultrasound are more accurate to differentiate benign from malignant thyroid nodule. The choice of radionuclides for routine imaging of thyroid gland between 99mTcO4- and 131I,99mTcO4- provides enough information to evaluate thyroid function, and 131I for differential thyroid cancer. There are no preoperative indications for FDG PET in thyroid tumors, and often used in the situation involving a negative radioiodine scan with the suspicious of metastasis spread. CT is not routinely used as a primary modality in the workup of a thyroid lesions,and is often reserved for selected cases with complex anatomy. MRI is capable of providing excellent anatomical detail of the thyroid gland, but no more advantage compared with CT.