中文摘要：

目的探讨18F—FDGPET／CT对肌无力患者的临床应用价值。方法回顾性分析41例2010年8月至2013年11月期间行全身18F-FDGPET／CT检查的不明原因肌无力患者资料，其中男28例，女13例，平均年龄62．6岁。患者最终诊断根据组织病理学结果及长期随访（8—46个月）得出，并获得18F-FDGPET／CT对肌无力患者良恶性病变的诊断效能。结果41例患者中，经组织病理学证实，12例为恶性病变（肺癌6例、淋巴瘤2例、脑胶质母细胞瘤、前列腺癌、肾透明细胞癌和结肠癌各1例），18F-FDGPET／CT均正确诊断；余29例为神经肌肉系统良性疾病，6例18F—FDGPET／CT发现高代谢病灶，2例18F-FDGPET／CT误诊为恶性病变。18F-FDGPET／CT对肌无力患者恶性肿瘤诊断的灵敏度为12／12，特异性为93．1％（27／29），准确性为95．1％（39／41），阳性预测值为12／14，阴性预测值为100％（27／27）。1例皮肌炎患者肌肉葡萄糖代谢弥漫性增高。结论 18F-FDGPET／CT有助于肌无力患者的病因诊断，早期发现潜在的肿瘤病灶，还有助于判断某些周围神经肌肉疾病受累的范围和程度。

英文摘要：

Objective To assess the value of lSF-FDG PET/CT in discovering the cause of myas- thenia. Methods Between August 2010 and November 2013, 41 cases （28 males, 13 females; average age 62.6 years） with myasthenia who underwent whole-body lSF-FDG PET/CT were enrolled in this retro- spective study. The final diagnoses were based on histopathology and clinical follow-up （8-46 months）, and the detecting efficiency of ISF-FDG PET/CT in patients with myasthenia was calculated. Results Of the 41 patients, 12 were histologically confirmed as having a malignancy including lung cancer （n = 6）, lymphoma （ n = 2）, spongioblastoma （ n = 1 ）, prostate cancer （ n = 1 ）, renal clear cell cancer （ n = 1 ） and colon canc- er （n= 1）. lS F-FDG PET/CT could detected all the primary malignancies and metastases. In 29 patients with benign diseases, abnormal FDG uptake lesions were found in 6 cases, and the rest 2 cases had false- positive results. The sensitivity, specificity, accuracy, positive predictive value and negative predictive val- ue of ISF-FDG PET/CT in detecting tumors in patients with myasthenia was 12/12, 93.1% （27/29）, 95.1% （39/41）, 12/14 and 100% （27/27）, respectively. FDG uptake in muscles increased diffusely was found in 1 patient with dermatomyositis. Conclusions 18F-FDG PET/CT is helpful to find causes of myas- thenia and can demonstrate the underlying malignancy in the early stage. It could also reveal the range and the extent of some patients with peripheral neuropathy and muscle diseases.