超声弹性成像技术预测甲状腺微小乳头状癌中央组淋巴结转移的价值

目的 探讨超声弹性成像技术弹性评分及弹性应变率（SR）预测甲状腺微小乳头状癌（PTMC）中央组淋巴结转移的价值。方法 选择2012年6月至2013年3月上海交通大学医学院附属瑞金医院经手术病理证实的82例PTMC患者共82个病灶，其中12例患者12个病灶伴有中央组淋巴结转移，70例患者70个病灶无中央组淋巴结转移。对所有病灶进行弹性评分，并检测病灶与周围正常甲状腺组织的SR。分别采用χ^2检验、独立样本t检验比较有中央淋巴结转移PTMC与无中央淋巴结转移PTMC弹性评分、SR的差异，并绘制操作者工作特性（ROC）曲线评价SR判断PTMC有无中央淋巴结转移的价值。结果 有中央淋巴结转移PTMC与无中央淋巴结转移PTMC的弹性评分差异无统计学意义（χ^2=5.00，P=0.08）；有中央组淋巴结转移PTMC的平均SR为2.44±0.61，高于无中央组淋巴结转移PTMC的平均SR 1.67±0.42，且差异有统计学意义（t=5.5，P=0.00）；PTMC与周围正常甲状腺组织的SR的ROC曲线下面积为0.847，当SR为2.01时判断PTMC有中央组淋巴结转移的敏感度、特异度和准确性分别为83.3%、81.4%、78.6%。结论 超声弹性成像技术弹性评分不能作为判断PTMC有无中央组淋巴结转移的指标，而SR可作为预测PTMC有无中央组淋巴结转移的指标。

Value of elastography in predicting central lymph nodes metastasis of papillary thyroid microcarcinoma

Objective To investigate the value of elasticity score and elasticity strain ratio （SR） in predicting the central lymph nodes metastasis of papillary thyroid microcarcinoma （PTMC）. Methods This study conducted a retrospective analysis of ultrasonography ifndings of 236 thyroid lesions from 208 patients. All of them underwent surgery in Ruijin Hospital of Shanghai Jiao Tong University from June 2012 to March 2013. Totally 82 PTMC from 82 patients were included in this study. Among them 12 patients with 12 PTMC had central lymph nodes metastasis. The elasticity score and SR were compared between metastasis and non-metastasis groups, and the receiver operating characteristic （ROC） curve of SR was calculated. Results The differences of PTMC elasticity score between two groups showed no statistical signiifcance （χ^2=5.00, P=0.08）. The average SR of the group with central lymph nodes metastasis is 2.44±0.61, which is higher than the group without lymph nodes metastasis whose average SR is 1.67±0.42. Differences are statistically signiifcant （t=5.5, P=0.00）. The area under curve of SR-ROC curve was 0.847. Using 2.01 as cutoff of SR, the sensitivity, speciifcity, accuracy of predicting central lymph nodes metastasis was 83.3%, 81.4%, 78.6%respectively. Conclusion The SR but not elasticity score could be a meaningful indicator for predicting lymph nodes metastasis.