Lyshchik Andrej, Higashi Tatsuya, Asato Ryo, Tanaka Shinzo, Ito Juichi, Hiraoka Masahiro, Insana Michael F, Brill Aaron B, Saga Tsuneo, Togashi Kaori
Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan.
Radiology. 2007 Apr;243(1):258-67. doi: 10.1148/radiol.2431052032. Epub 2007 Feb 9.
To prospectively estimate the accuracy of sonoelastography in the differentiation of benign and metastatic cervical lymph nodes (LNs) in patients suspected of having thyroid or hypopharyngeal cancer, with histologic nodal findings as the reference standard.
The study protocol was approved by the hospital review board; each patient gave written informed consent. One hundred forty-one peripheral neck LNs (60 metastatic, 81 metastasis free) in 43 consecutive patients (22 men, 21 women; mean age, 58 years +/- 13 [standard deviation]) were examined. Patients referred for surgical treatment of suspected thyroid or hypopharyngeal cancer were examined with gray-scale ultrasonography (US), power Doppler US, and sonoelastography. At gray-scale and power Doppler US, the following LN characteristics were evaluated: short-axis diameter, short-to-long-axis diameter ratio, echogenicity, calcifications, and vascularity. A four-point rating scale was used to evaluate the US elastograms for LN visibility, relative brightness, margin regularity, and margin definition. In addition, strains of LN and surrounding neck muscles were measured on elastograms, and the muscle-to-LN strain ratio--that is, the strain index-was calculated. The diagnostic potential of the examined criteria for metastatic involvement was evaluated with univariate analysis and multivariate generalized estimating equation (GEE) regression. P < .05 indicated statistical significance.
A strain index greater than 1.5 had high utility in metastatic LN classification, with 98% specificity, 85% sensitivity, and 92% overall accuracy. These results were significantly better than those obtained by using the best gray-scale criterion--that is, a short-to-long-axis diameter ratio greater than 0.5-which had 81% specificity, 75% sensitivity, and 79% overall accuracy.
Sonoelastography had high accuracy (92%) in the differentiation of benign and metastatic cervical LNs in patients suspected of having thyroid or hypopharyngeal cancer.
以前瞻性方式评估超声弹性成像在疑似甲状腺或下咽癌患者中鉴别颈部良性和转移性淋巴结（LN）的准确性，以组织学淋巴结检查结果作为参考标准。
本研究方案经医院伦理委员会批准；每位患者均签署了书面知情同意书。对43例连续患者（22例男性，21例女性；平均年龄58岁±13[标准差]）的141个颈部外周淋巴结（60个转移性，81个无转移）进行了检查。因疑似甲状腺或下咽癌而转诊接受手术治疗的患者接受了灰阶超声（US）、能量多普勒超声和超声弹性成像检查。在灰阶和能量多普勒超声检查中，评估了以下淋巴结特征：短轴直径、短轴与长轴直径比、回声、钙化和血管情况。采用四点评分量表评估淋巴结的超声弹性图，评估指标包括淋巴结可见性、相对亮度、边缘规则性和边缘清晰度。此外，在弹性图上测量淋巴结和周围颈部肌肉的应变，并计算肌肉与淋巴结的应变比，即应变指数。通过单因素分析和多因素广义估计方程（GEE）回归评估所检查标准对转移累及的诊断潜力。P<0.05表示具有统计学意义。
应变指数大于1.5在转移性淋巴结分类中具有较高的效用，特异性为98%，敏感性为85%，总体准确性为92%。这些结果显著优于使用最佳灰阶标准（即短轴与长轴直径比大于0.5）所获得的结果，后者的特异性为81%，敏感性为75%，总体准确性为79%。
超声弹性成像在疑似甲状腺或下咽癌患者中鉴别颈部良性和转移性淋巴结方面具有较高的准确性（92%）。
