甲状腺实性低回声结节良恶性鉴别：声辐射力脉冲弹性成像技术的应用价值

目的评估声辐射力脉冲弹性成像（ARFI）技术声触诊组织成像（VTI）和声触诊组织定量（VTQ）对常规超声表现为甲状腺实性低回声结节良恶性的鉴别诊断价值。方法回顾性分析经手术病理证实的62例患者77个甲状腺实性低回声结节的常规超声、VTI及VTQ特征。分析结节的超声声像图特征,如结节的形态、边界、有无微钙化、内部血流,周边声晕及纵横比。将VTI图像分为6级,级数越高代表组织硬度越大。VTQ以横向剪切波速度（SWV）值表示,SWV值越大表示组织硬度越高。结果 77个甲状腺实性低回声结节经手术病理证实良性结节49个,恶性结节28个。常规超声声像图特征：形态、边界、微钙化、内部血流、周边声晕及纵横比对甲状腺恶性结节的敏感度、特异度、准确性、阳性预测值及阴性预测值范围分别为39.3%（11/28）～78.6%（22/28）、26.5%（13/49）～83.7%（41/49）、45.5%（35/77）～70.1%（54/77）、37.9%（22/58）～61.9%（13/21）及68.4%（13/19）～76.5%（26/34）;VTI技术对甲状腺恶性结节的敏感度、特异度、准确性、阳性预测值及阴性预测值分别为85.7%（24/28）、95.9%（47/49）、92.2%（71/77）、92.3%（24/26）及92.2%（47/51）;VTQ技术对甲状腺恶性结节的敏感度、特异度、准确性、阳性预测值及阴性预测值分别为67.9%（19/28）、71.4%（35/49）、70.1%（54/77）、57.6%（19/33）及79.5%（35/44）。结论 VTI对甲状腺实性低回声结节良恶性的鉴别诊断能力优于常规超声及VTQ技术,对甲状腺良恶性结节的评估较常规超声及VTQ更具优势。

Differential diagnosis between benign and malignant solid hypoechoic thyroid nodules in ultrasonography:value of acoustic radiation force impulse imaging

Objective To evaluate the value of virtual touch tissue imaging（VTI）and virtual touch tissue quantification （VTQ）of acoustic radiation force impulse imaging （ARFI） in the differential diagnosis between benign and malignant solid hypoechoic thyroid nodules in ultrasonography. Methods Retrospective analysis was performed to evaluate the uhrasonography, VTI and VTQ features of 77 histologically proven solid hypoechoic thyroid nodules in 62 patients. The uhrasonography features of the nodules were analyzed, such as the nodule shape, margin, internal microcalcification, intranodular blood flow, peripheral halo sign and anteroposterior to transverse diameter ratio with solid hypoechoic thyroid nodules. The VTI features were divided into 6 grades and higher grade represented harder tissue. The VTQ was expressed as the shear wave velocity（SWV） and greater SWV represented stiffer tissue. Results obtained in different nodules were primarily compared using the X2 test. Then the sensitivity, specificity, accuracy, positive predictive value （PPV） and negative predictive value （NPV）for differential diagnosis by ultrasonography and ARFI were investigated. Results All 77 pathologically proven thyroid nodules included 49 benign and 28 malignant nodules. The sensitivity, specificity, accuracy, PPV and NPV of the ultrasonography features for differential diagnosis ranged from 39.3% （ 11/28 ） to 78.6% （ 22/28 ） ,26.5% （ 13/49 ） to 83.7% （41/49） ,45.5% （35/77） to 70.1% （54/77） ,37.9% （22/58）to 61.9% （ 13/21 ） and 68.4% （ 13/19 ） to 76.5 % （26/34）,respectively. The sensitivity, specificity, accuracy, PPV and NPV of VTI were 85.7% （24/28）, 95.9 % （47/49）, 92.2% （71/77） ,92.3% （24/26） and 92.2% （47/51） ,respeetively. For VTQ, the values were 67.9% （ 19/28 ）, 71.4% （35/49） ,70.1% （54/77） ,57.6% （19/33） and 79.5% （35/44） ,respectively. Conclusions VTI of ARF1 elastography showed superior performance in the differential diagnosis between malignant and benign solid hypoeehoic thyroid nodules compared with ultrasonography and VTQ. Therefore, VTI of ARFI elastography showed superior performance in the differential diagnosis between malignant and benign nodules compared with ultrasonography and VTQ.