剪切波弹性成像与实时组织弹性成像技术在甲状腺结节良恶性鉴别诊断中的应用价值

目的比较剪切波弹性成像（SWE）技术与实时组织弹性成像技术在甲状腺结节良恶性鉴别诊断中的应用价值。方法选择2012年2月至2012年12月于中山大学附属第一医院接受甲状腺手术的49例患者共59个甲状腺结节,于术前同一时间分别接受SWE和实时组织弹性成像检查。所有患者均经手术病理证实。59个甲状腺结节中,41个结节为良性,18个结节为恶性。对于SWE技术,绘制受试者操作特性（ROC）曲线得出鉴别诊断甲状腺结节良恶性的最佳阈值并进行诊断;对于实时组织弹性成像技术,采取Rago 5分法对甲状腺结节良恶性进行鉴别诊断。以手术病理结果作为金标准,分别计算SWE技术和实时组织弹性成像技术鉴别诊断甲状腺良恶性结节的敏感度、特异度、准确性、阳性预测值、阴性预测值。结果 ROC曲线显示,SWE技术鉴别诊断甲状腺结节良恶性的最佳阈值为38.3 k Pa。SWE和实时组织弹性成像技术鉴别诊断甲状腺结节良恶性的敏感度、特异度、准确性、阳性预测值、阴性预测值分别为72.2%（13/18）、85.4%（35/41）、81.4%（48/59）、68.4%（13/19）、87.5%（35/40）和77.8%（14/18）、87.8%（36/41）、84.8%（50/59）、73.7%（14/19）和90.0%（36/40）。实时组织弹性成像技术鉴别诊断直径≤1 cm的甲状腺小结节良恶性的敏感度为87.5%（7/8）,高于SWE技术鉴别诊断直径≤1 cm的甲状腺小结节良恶性的敏感度50.0%（5/5）。SWE技术鉴别诊断直径〉3 cm的甲状腺大结节良恶性的准确性为100%（5/5）,高于实时组织弹性成像技术鉴别诊断直径〉3 cm的甲状腺大结节良恶性的准确性80.0%（4/5）。结论无论是SWE技术还是实时组织弹性成像技术对甲状腺结节良恶性的鉴别诊断都有很好的应用价值。但SWE技术对于直径〉3 cm的甲状腺大结节良恶性的鉴别诊断有一定的优势,而实时组织弹性成像技术对直径≤1 cm的甲状腺小结

Preliminary comparative study of shear wave elastography versus quasi-static elastography on evaluation of thyroid nodules

Objective To comparatively evaluate two real-time elastic imaging called shear wave elastography（SWE） and quasi-static elastography for distinguishing malignant thyroid nodules from benign.Methods From February 2012 to December 2012,46 patients scheduled thyroid surgery with 59 focal thyroid nodules in the First Affi liated Hospital of Sun Yat-sen University underwent SWE and quasi-static elastography at the same time.For SWE,the optimal cut-off value was calculated by receiver operating characteristic（ROC） curve to discriminate malignant from benign lesions.For quasi-static elastography,elastograms were assessed by Rago criteria.Histopathologic results after surgery were adopted as diagnostic reference.Compared with pathological results,the sensitivity,specificity,accuracy,positive predictive value（PPV） and negative predictive value（NPV） of SWE or quasi-static elastography were calculated.Results For SWE,the optimal cut-off value according to ROC curve was 38.3 k Pa.Generally,the specifi city,sensitivity,accuracy,PPV and NPV were 72.2%（13/18）,85.4%（35/41）,81.4%（48/59）,68.4%（13/19） and 87.5%（35/40） for SWE,and 77.8%（14/18）,87.8%（36/41）,84.8%（50/59）,73.7%（14/19） and 90.0%（36/40） for quasi-static elastography,respectively.For nodules ≤ 1 cm,quasi-static elastography showed a sensitivity of 87.5%,which was higher than that of SWE（50%）.However,for nodules〉3cm,the accuracy of SWE was higher than quasi-static elastography（100% vs 80%）.Conclusion The results demonstrated that either SWE or quasi-static elastography has good diagnostic performance on distinguishing malignant thyroid nodules from benign.SWE has advantage for nodules〉 3 cm,whereas quasi-static elastography shows better diagnostic performance for nodules ≤ 1 cm.